Glossary (ch. 1-10, 22) Flashcards
1
Q
abdominal cavity
A
body cavity located below the diaphragm; contains liver, stomach, pancreas, spleen, kidneys, urinary bladder, intestines, and gonads; also called the abdominopelvic cavity
2
Q
ABO blood group:
A
red-blood-cell antigen group consisting of antigens A and B
3
Q
abscisic acid
A
hormone that signals plant tissues to remain dormant; also called ABA
4
Q
abscission layer
A
special cell layer that forms to cut a leaf or fruit from a stem
5
Q
absorption
A
movement of water, digested food, and other dissolved substances from the small intestine into the bloodstream
6
Q
accommodation
A
increase in the curvature of the eye’s lens to focus on nearby objects
7
Q
achene
A
simple fruit consisting of a seed and a shell, much thinner than the shell of a nut
8
Q
action potential
A
brief pulse of positive charge that travels down the axon of a neuron that has been triggered to fire
9
Q
active transport
A
movement of molecules across the cell membrane from a place of lower concentration to a place of higher concentration with the expenditure of energy
10
Q
acute confusion
A
disturbance of the brain caused by physical illness elsewhere in the body
11
Q
adipose cell
A
fat cell
12
Q
adventitious root
A
root that grows from an unexpected region of a plant
13
Q
agar
A
gelling agent, derived from red algae, used as a culture medium for growing bacteria in the laboratory
14
Q
agent dispersal
A
seed dispersal in which an outside agent carries the seeds
15
Q
aggregate fruit
A
fruit that forms from a flower that has several pistils
16
Q
albumin
A
blood protein that helps regulate the water content of the blood
17
Q
alga
A
member of the group containing the smallest green, chlorophyll-containing organisms
18
Q
algin
A
gummy substance derived from kelp and used to hold liquids in an emulsion
19
Q
alimentary canal
A
tube leading from the mouth to the anus that forms the main portion of the digestive system
20
Q
all-or-none principle
A
principle stating that when a muscle fiber is stimulated to contract it does so completely and then relaxes completely
21
Q
alternate
A
leaf pattern in which only one leaf grows from each node in an alternating pattern up the branch
22
Q
alternation of generations
A
life cycle, found in ferns, mosses, and some other plants, that involves both asexual and sexual production in alternating generations
23
Q
alveolus
A
one of the microscopic air sacs of the lungs in which gas exchange takes place; plural ‘alveoli’
24
Q
Alzheimer’s disease
A
disease similar to dementia but much more severe and sometimes occuring much earlier in life
25
amino acids
group of about 20 types of simple molecules that combine to produce proteins
26
amnesia
memory loss
27
anemia
disorder resulting from too little oxygen being transported to body cells
28
angiosperm
plant with flowers that produce seeds covered by fruit
29
Animalia
animal kingdom; consists of multicellular eukaryotes without cell walls
30
annual
plant that develops from a seed and produces new seeds in a single growing season
31
annual growth ring
distinct layer in the xylem of a woody stem formed by annual variation in the rate of secondary growth
32
anther
enlarged pollen-producing structure at the tip of a stamen
33
anthocyanin
pigment in leaves that produces bright red, blue, and purple colors
34
Anthophyta
phylum consisting of angiosperms
35
antigen
carbohydrate molecule on the surface of a cell that functions as an identification unit
36
antioxidant
substance that neutralizes harmful free radicals
37
anus
valve that closes the rectum and serves as the digestive tract's second opening to the exterior
38
aorta
the body's largest artery, from which all other systemic arteries branch
39
aortic semilunar valve
heart valve that allows blood to exit the left ventricle and enter the aorta
40
apoptosis
process through which a cell can trigger its own death when it is no longer needed or no longer able to survive; also called programmed cell death
41
appendictis
condition caused by infection of the vermiform appendix
42
appendicular skeleton
division of the skeletal system that includes the shoulders, hips, and appendages
43
appendix
small, fingerlike structure attached to the cecum
44
aqueous humor
clear fluid in the eye that fills the space between the cornea and the iris and lens
45
Archaebacteria
kingdom consisting of prokaryotes that do not contain peptidoglycan in their cell walls
46
arteriole
small blood vessel connecting an artery to capillaries
47
arteriosclerotic dementia
dementia caused by death of brain cells due to blockage in the arteries
48
artery
thick-walled blood vessel that transports blood away from the heart
49
arthritis
inflammation of the joints
50
astigmatism
focusing problem in which the light rays entering the eye are bent incorrectly, usually caused by an incorrectly curved cornea
51
atherosclerosis
form of arteriosclerosis in which a buildup of plaque and scar tissue narrow the inside of an artery
52
ATP
special phosphorus compound that serves as the energy carrier of the cell; short for adenosine triphosphate
53
ATP synthase
molecular machine that generates ATP using power provided by the flow of hydrogen ions
54
atrium
either of the two thin-walled upper chambers of the heart; plural 'atria'
55
atrophy
muscle degeneration
56
auditory nerve
nerve connecting the hairlike nerve cells of the cochlea to the brain
57
autonomic nervous system
portion of the peripheral nervous system that controls the heart and other internal organs
58
autotroph
organism that makes its own food using an inorganic energy source; also called a producer
59
auxin
any of a group of plant growth hormones that are involved in many tropisms, cause the apical stem to remain dominant, and stimulate root growth and fruit formation
60
A-V valve
either of the two heart valves that allow blood to flow from an atrium into a ventricle
61
axial skeleton
division of the skeletal system that includes the head, spine, and rib cage
62
axon
long extension of a neuron that relays nerve impulses from the cell body to other neurons
63
ball-and-socket joint
joint in which the rounded head of a bone fits into a hollow socket in another bone, allowing the bone to move in two planes and rotate in place
64
bark
outer section of a woody stem, which provides protection and helps transport food
65
basidium
microscopic, club-shaped, spore-producing structure of a club fungus; plural 'basidia'
66
behaviorism
philosophy that the behavior of a person is determined by his environment, not his mind
67
berry
simple fruit in which the entire ovary is freshy and juicy throughout
68
biceps brachii
muscle on the front of the upper arm that bends the forearm; also called 'biceps'
69
bicupsid
any of the four light-grinding teeth next to the cupsids (one pair on each side) on each jaw; also called 'premolar'
70
bicupsid valve
heart valve connecting the left atrium and left ventricle; also called 'mitral valve'
71
biennial
plant that lives through two growing seasons to complete its life cycle
72
bile
greenish substance secreted from the liver that helps in the digestion of fats
73
bile salts
group of substances in bile that emulsify fats
74
binomial nomenclature
system of assigning scientific names to organisms by using two words (genus and species) for each scientific name
75
biology
study of living things
76
blade
flat, green portion of a leaf
77
blind spot
spot on the retina where the optic nerve exits the eye and there are no light-sensitive cells
78
blood
thick fluid that transports gases, nutrients, and wastes as part of the circulatory system
79
blood pressure
force that blood exerts upon the walls of the blood vessels
80
blood-brain barrier
system of tightly sealed capillary walls that prevents bacteria, viruses, and harmful molecules from entering the brain and spinal cord
81
bolus
small ball into which food is formed by the tongue
82
bone conduction
transmission of vibrations (caused by speech, etc.) from the jawbone to the inner ear
83
botany
study of plants
84
botulism
severe food poisoning caused by the bacterium Clostridium botulinum
85
bract
special leaf that looks like a flower petal
86
brain
principal organ of the nervous system; the chief organ of the mind
87
brain stem
portion of the brain that connects the rest of the brain to spinal cord; includes three regions responsible for most automatic body functions
88
bran
shell-like fruit covering of a wheat kernel
89
broadleaf tree
tree that has broad, flat leaves
90
bronchial asthma
allergic condition characterized by spasms of the bronchial tube muscles
91
bronchial tube
a bronchus or any of its branches
92
bronchiole
small tube, branching from a secondary bronchus, that ends in alveoli
93
bronchitis
inflammation of the lining of the bronchial tubes
94
bronchus
either of the two tubes into which the trachea divides, one going to each lunch; plural 'bronchi'
95
bryophyte
spore-bearing novascular plant
96
bud
part of a stem that allows it to grow in length or develop new stems, flowers, or leaves
97
bud scale
any of the scales that cover a bud in winter to protect it from frost injury and drying out
98
budding
form of grafting in which the scion is a bud
99
bud-scale scar
ring that circles a stem, indicating where last year's growth started
100
bulb
structure made of a special stem and leaves that stores food underground
101
bundle scar
marking on a leaf scar that indicates a passage point of vascular tissue from the stem to the leaf petiole
102
Calorie
unit used to measure the energy content of food; equal to the amount of energy needed to raise the temperature of one kilogram (or one liter) of water by one degree Celsius
103
calyx
collective term for a flower's sepals
104
cambium
internal layer of meristematic tissue that enables stems and roots to grow in diameter
105
capillarity
upward movement of liquids through a very narrow tube due to differences in adhesion and cohesion; also called capillary action
106
capillary
microscopic blood vessel, linking an artery and vein, in which the exchanges between body cells and blood take place
107
capsule
spore case of a moss plant
108
carbohydrate
organic compound consisting of the elements carbon, hydrogen, and oxygen in about a 1:2:1 ratio
109
cardiac conduction system
system of special cardiac muscle fibers that generate electrical impulses and distribute them to all parts of the heart
110
cardiac muscle
self-stimulating striated cardiac tissue found in the heart
111
cardiac veins
system of veins that collect blood from the heart tissues and carry it to the right atrium
112
cardiologist
doctor specializing in the heart and its disorders
113
cardiovascular system
another name for the circulatory system
114
carotene
pigment in leaves that produces yellowish-orange colors
115
carpal
any of the eight bones of the wrist
116
carrageenan
gelatinous substance that comes from the alga Irish moss and is used in many food products
117
cartilage
tough, rubbery connective tissue that cushions the joints between bones
118
catalyst
substance that speeds up a chemical change but is not consumed in the process
119
catkin
long, tassel-like cluster formed by the flowers of some trees
120
cecum
pouch in the large intestine at the junction with the small intestine
121
cell
basic unit of structure and function of living things
122
cell biology
another name for cytology, the study of cells
123
cell body
central portion of neuron, which contains the nucleus and most of the cytoplasm
124
cell cycle
life cycle of a cell
125
cell membrane
thin, flexible barrier that surrounds a cell, separates it from its environment, and regulates what enters and leaves the cell; also called plasma membrane
126
cell theory
idea that all living things are composed of living units called cells and of cell products and that all cells come only from preexisting cells
127
cell wall
rigid, boxlike structure outside the cell membrane of a plant cell that stiffens, supports, and protects the cell
128
cellular respiration
process through which a cell breaks down chemical substances such as sugars and combines them with oxygen (oxidizes them) to release energy; also called aerobic respiration
129
cellulase
enzyme that weakens the cell walls of the abscission layer
130
cellulose
complex carbohydrate that forms the cell wall of plants and is a form of insoluble fiber
131
cementum
bonelike substance that fastens the root of a tooth to the jaw
132
central nervous system
portion of the nervous system that consists of the brain and spinal cord
133
centrosome
microtubule-organizing center of a human or animal cell
134
cereal
any of the types of grass used by man for food; the grain of such a plant
135
cerebellum
portion of the brain that coordinates skeletal muscle activity
136
cerebral cortex
outer layer of the cerebrum, which contains much of the brain's gray matter
137
cerebral palsy
damage to the cerebral motor area, resulting in reduced motor abilities without affecting intelligence
138
cerebrospinal fluid
clear fluid that circulates through the fibers of the arachnoid mater
139
cerebrum
portion of the brain responsible for consciousness, memory, voluntary actions, thinking, and intelligence
140
cervical
of or related to the neck
141
cervical vertebra
any of the seven vertebrae of the neck
142
chaff
husk of a wheat kernel
143
chamber
any of the four internal hollow spaces of the heart
144
cheese mold
any of the molds used to make some types of cheese
145
chemical sense
any of the senses that result from chemical stimuli
146
chemoreceptor
receptor for a chemical sense
147
chlorophyll
green pigment of plants that enables them to capture the energy of light
148
chloroplast
organelle, found in the cells of green plants, that is a tiny chemical "factory" that uses light to manufacture food
149
cholesterol
lipid used by the body to make bile, vitamin D, and important hormones and used in cell membranes
150
choroid
layer of tissue within the uvea that provides most of the cell's nourishment
151
chromosome
individual DNA molecule within a cell
152
chyme
thick liquid formed in the stomach, consisting of digestive juices and partially digested food
153
ciliary body
muscular structure near the front of the uvea that adjusts the lens of the eye to focus at varying distances
154
cilium
tiny hairlike projection extending from the cell membrane of some cells
155
circulatory shock
potentially lethal condition in which the body's blood pressure falls to a critical low
156
circulatory system
body system that brings food, water, and oxygen to the cells and carries away carbon dioxide and waste products; also called cardiovascular system
157
cirrhosis
buildup of fatty deposits and fibrous tissue in the liver
158
class
level of taxonomy between phylum and order
159
clavicle
collarbone
160
club fungi
group of fungi that produce spores in club-shaped basidia
161
club moss
creeping vascular plant that has an erect stem and bears spores in club-shaped, cone-like structures; also called ground pine
162
coccyx
bone, consisting of four separate vertebrae that are fused in adults, that is an attachment for muscles involved in standing and the elimination of wastes; also called tailbone
163
cochlea
coiled tube in the inner ear that detects vibrations and sends them to the brain
164
coenzyme
molecule that assists a cell's enzymes in performing their jobs
165
collagen
tough, resilient protein fiber that reinforces bone and, with elastin, gives skin its strechability and elasticity
166
colon
long, tubular section of the large intestine that absorbs water from undigested food
167
colony
group of single-celled algae clumped together and living as a group
168
colorblind
unable to distinguish one or more of the primary colors of light
169
coma
prolongued unconscious state that may not be reversible
170
common bile duct
duct through which bile enters the small intestine from the gallbladder
171
common cold
most common respiratory disease, caused by any of over a hundred different types of viruses
172
compact bone
strong, dense tissue composing the outer layer of a bone
173
complete flower
flower that has all four basic flower parts (sepals, petals, stamens, and pistils)
174
complex carbohydrate
carbohydrate formed from a long chain of simple carbohydrates; also called polysaccharide
175
compound fracture
fracture in which the broken bone pierces through the skin; also called open fracture
176
compound leaf
leaf that has more than one blade on every petiole
177
concussion
period of paralysis of the central nervous system accompanied by a short period of unconsciousness
178
cone
type of cell in the retina that detects colors
179
conifer
cone-bearing gymnosperm
180
connective tissue
any of the tissues that connect parts of the body
181
constipation
condition that occurs when feces are so dry that defecation is difficult
182
cork
plant structural tissue that forms the bark of woody plants
183
cork cambium
cambium tissue that produces a new cork tissue
184
corm
swollen stem that stores food underground; distinguished from a bulb by a thicker stem and thinner leaves
185
corn smut
smut that attacks the tassels and ears of corn plants, forming large, shiny blisters
186
cornea
transparent structure that replaces the sclera at the front of the eye
187
corolla
collective term for a flower's petals
188
coronary arteries
two arteries that branch from the base of the aorta to supply blood to the cardiac muscle cells
189
coronary circulation
portion of systemic circulation in which blood flows to the heart muscle and back to the right atrium
190
corpus callosum
mass of nerve fibers through which the cerebral hemispheres communicate
191
cortex
food-storage tissue in a herbaceous stem in which the vascular bundles are embedded; similar tissue in a root or young woody stem
192
cotyledon
portion of an angiosperm embryo that contains stored food used to supply the energy for sprouting
193
cranial cavity
body cavity containing the brain
194
cranial nerve
any of the twelve pairs of nerves that branch directly from the brain stem
195
cranium
portion of the skull that protects the brain; also called braincase
196
cross-pollination
pollination in which the pollen from one plant is transferred to another plant
197
crown
bushy head of a tree OR part of a tooth that is exposed above the gums
198
cuspid
either of two tearing teeth flanking the incisors on each jaw; also called canine
199
cutaneous membrane
another term for the skin
200
cuticle
waxy layer that usually covers the epidermal tissue of a plant's shoot system
201
cutting
piece of stem or root that can grow into a new plant; also called a slip
202
cyanobacteria
group of bacteria that form colonies resembling those of unicellular algae; also called blue-green algae
203
cyad
palmlike tropical gymnosperm
204
cystic fibrosis
recessive genetic disease caused by a defect that affects the chlorine gates of lung cell membranes; abbreviated CF
205
cytokinesis
process in which the cytoplasm of a cell separates to form two separate cells
206
cytokinin
any of a group of plant growth hormones that promote cell division and stimulate lateral buds to grow into new shoots
207
cytology
study of cells; also called cell biology
208
cytoplasm
jellylike fluid medium of the cell, containing organelles and numerous dissolved chemicals
209
cytoskeleton
intricate internal skeleton that helps a cell maintain its shape
210
deciduous
describes a tree that loses its leaves each fall
211
deltoid
muscle that forms the curve of the shoulder; lifts the upper arm away from the body
212
dendrite
short, branched extension of a nerve cell that receives nerve impulses from other neurons and conducts them toward the cell body
213
denitrifying bacteria
bacteria in the soil that convert unused nitrates back into atmospheric nitrogen
214
dental caries
disease in which acid attacks the teeth, penetrating the enamel and dentin; also called tooth decay and cavities
215
dentin
bonelike layer that surrounds the pulp of a tooth
216
depressant
substance that slows the central nervous system
217
desmid
any of a large group of unicellular freshwater green algae characterized by a beltlike constriction that divides cells into two identical semicells
218
diaphragm
thick sheet of muscle that separates the thoracic cavity from the abdominal cavity
219
diaphysis
shaft of a long bone
220
diarrhea
condition that occurs when insufficient water is removed from feces, resulting in soft and watery feces and frequent defecation
221
diastole
relaxing and filling phase of heart action
222
diatom
any of a group of yellow algae characterized by rigid cell walls composed of silica
223
diatomaceous earth
substance formed from packed layers of diatom shells; also called diatomite
224
dicot
plant with two cotyledons per seed; typically characterized by flower petals that are arranged in groups of four or five, leaves that are usually broad and flat with branching venation, and a taproot system
225
dietary fiber
group of complex carbohydrates that are not digested or incorporated into the body
226
diffusion
process of mixing molecules of one substance through another by random molecular motion
227
digestion
process that changes food substances with large, complex chemical molecules into substances with smaller, less complex molecules
228
digestive enzyme
any of the enzymes involved in digestion
229
digestive gland
secreting body that produces digestive enzymes and digestive juices
230
digestive system
body system that breaks down food into a form that can be absorbed by the bloodstream
231
dinoflagellate
unicellular aquatic alga that has two unlike flagella used for locomotion
232
dioecious
having staminate and pistillate flowers borne by separate plants
233
disk flower
one of the flowers in the center of a composite flower head
234
dislocation
injury in which a joint is overstressed to the extent that a bone pops out of alignment
235
DNA
chemical, found in the nucleus, that stores the genetic information needed for cellular function; short for deoxyribonucleic acid.
236
dormancy
period of inactivity, which helps prevent seeds from sprouting when conditions are unfavorable for the growth of young plants
237
drupe
simple fruit that has an outer fleshy layer and an inner woody layer
238
dry fruit
fruit that has a dry ovary
239
duodenum
first and shortest section of the small intestine
240
dysentery
painful infection of the colon that causes severe diarrhea and cramps accompanied by blood in the feces
241
dyspepsia
gastric indigestion
242
eardrum
membrane stretched across the ear canal that vibrates in response to sound waves
243
edema
condition in which the body tissues absorb extra fluids and cannot maintain proper water balance
244
egg cell
female reproductive cell
245
electrocardiogram
medical procedure in which the tiny electrical currents in the heart are detected by electrodes taped to the patient's skin; abbreviated EKG or ECG
246
ellipsoid joint
joint that consists of a bone with a convex surface that fits into a concave portion of another bone and that allows movement in two planes but does not permit rotation; also called condyloid joint
247
embryo
living part within a seed that develops into a new plant
248
emphysema
progressive deterioration of the alveoli caused by malfunctioning enzymes
249
emulsification
process of breaking large droplets into smaller droplets
250
enamel
mineral substance that covers the crown of a tooth
251
endocardium
inner layer of the heart, which provides a smooth coating for the heart's interior
252
endocrine gland
any of the glands within the endocrine system, which secrete hormones into the bloodstream
253
endocrine system
body system containing hormone-producing glands
254
endocytosis
process by which a cell takes in large substances
255
endoplasmic reticulum
network of interconnected sacs and tubules that is connected to the nucleus and extends through much of the cell; abbreviated ER
256
endosperm
part of a seed that provides nutrition to the growing embryo, such as the starchy part of a wheat kernel
257
enzyme
large protein molecule that is a catalyst to carry out chemical reactions
258
epicardium
layer of slippery tissue covering the outside of the heart to allow the heart to move easily within the pericardial sac
259
epidermal tissue
plant structural tissue that protects and covers leaves, roots, stems, and other exposed areas and prevents excessive water loss and injury by outside agents
260
epidermis
outer layer that provides covering and protection to plant structures
OR
outermost layer of the skin
261
epiglottis
small flap of cartilage in the pharynx that closes the top of the trachea during swallowing
262
epilepsy
disorder in which neurons malfunction and begin to fire together over and over, disrupting ordinary cerebral processing and causing unconsciousness
263
epiphysis
bulged end of a long bone
264
epithelial tissue
any of the tissues that line body parts, cover and protect organs, regulate temperature, and regulate what enters and exits organs
265
ER
abbreviation for endoplasmic reticulum
266
ER lumen
internal cavity of the edoplasmic reticulum
267
erector spinae
muscle that extends along the spinal column from the upper back to the pelvis; straightens the back
268
esophagus
foot-long muscular tube connecting the pharynx to the stomach
269
ethylene
hydrocarbon that functions as a plant hormone to signal leaf abscission and to trigger green fruits to ripen
270
Eubacteria
bacteria kingdom; consists of prokaryotes with cell walls made of peptidoglycan
271
eukaryote
organism that has a membrane-bound nucleus and membrane-enclosed organelles
272
eustachian tube
tube connecting the throat to the middle ear
273
evergreen
describes a tree that retains its leaves throughout the winter
274
excretory system
body system that excretes waste materials from the body
275
exhalation
process in breathing in which air rushes from the lungs due to increased pressure
276
exocytosis
process by which waste products are eliminated from the cytoplasm
277
external oblique
muscle that connects the ribs to the pelvis but more to the side than does the rectus abdominis
278
external respiration
process of breathing
279
extracellular fluid
fluid that surrounds the body's cells
280
extrinsic muscles
set of six muscles that move the eye
281
eye (in plants)
node consisting of buds and small leaves, found on a tuber
282
eyelid
protective skin structure that blinks to keep foreign objects from entering the eye and cleans and moistens the eyeball
283
facial skeleton
bones that are the framework fo the face and jaw
284
family
level of classification between order and genus
285
farsightedness
the ability to see distant objects better than near objects due to the eye being too short or the lens being too flat; also called hyperopia
286
fascia
tough, translucent sheath encasing a muscle; also called epimysium
287
fat
molecule consisting of three fatty acid molecules attached to a single glycerol molecule; also called triglyceride
288
fat-soluble vitamin
any of the vitamins that are insoluble in water and can accumulate in the body if ingested in excess
289
fatty acid
simplest type of lipid molecule, made of carbon and oxygen atoms attached to a long chain of carbon and hydrogen atoms
290
feces
undigested waste materials from the digestive process
291
feedback mechanism
body mechanism that helps maintain homeostatis by directing changes in the body and directing the body to respond appropriately
292
femur
thigh bone
293
fermentation
process by which cells produce ATP when the oxygen required for cellular respiration is not available; also called anaerobic respiration
294
fern
nonflowering vascular plant with spore-bearing leaves and horizontal underground stems
295
fertilization
process in which a sperm cell fuses with an egg cell to form a new organism
296
fibrinogen
blood protein that helps in blood clotting
297
fibrous root
type of root system in which the primary root remains small and many slender secondary roots grow from it in all directions
298
fibula
thin bone of the lower leg
299
filament
slender, elongated part of a stamen
OR
hairlike structure formed by green algae that join end to end, forming a long chain of cells
300
flagellum
whiplike tail that extends from a cell and is used for propulsion; plural flagella
301
flat bone
bone that has a flattened shape
302
fleshy fruit
fruit that has a fleshy ovary
303
fleshy root
taproot that enlarges to store large quantities of food
304
flower
reproductive structure of an angiosperm
305
fontanel
tough connective-tissue membrane connecting the bones of an infant's cranium
306
food poisoning
gastrointestinal disease caused by consumption of food contaminated with bacteria or bacterial toxins
307
forage grass
any of the types of grass used to feed livestock
308
fovea
small depression on the retina where the light-sensitive cells are most densely packed
309
fracture
crack or break in a bone
310
freely movable joint
type of joint that allows a wide range of motion; also called synovial joint
311
frond
fern leaf
312
frontal lobe
lobe of the cerebrum corresponding to the frontal bone; associated with personality, judgement, and self-control; includes motor area
313
fruit
ripened ovary of a flower
314
fruiting body
umbrella-shaped reproductive structure formed by mushrooms; similar reproductive structure formed by another club fungus
315
Fungi
fungus kingdom; consists of multicellular eukaryotes that have cell walls and do not conduct photosynthesis
316
gallbladder
saclike organ that stores bile
317
gamete
reproductive cell (sperm cell or egg cell)
318
gametophyte
sexually reproducing generation in alteration of generations
319
ganglion
mass of neuron cell bodies; plural ganglia
320
gastric juice
digestive juice formed by the secretions of the stomach
321
gastrocnemius
muscle that forms the bulge on the upper calf; extends the foot downward
322
genus
level of classification between family and species; plural genera
323
geotropism
growth of a plant in response to gravity
324
germ
embryo of a wheat kernel
325
germination
process in which a seed sprouts
326
gibberellin
any of a group of plant growth hormones that help regulate normal plant growth and trigger germination of dormant seeds
327
gill
basidia-containing "spoke" on the underside of a mushroom cap
328
gingivitis
periodontal disease in which the gums become tender and inflamed due to accumulation of plaque and tartar
329
ginkgo
unique oriental gymnosperm with fan-shaped leaves; also called maidenhair tree
330
glaucoma
condition in which the pressure of the fluid inside the eye becomes much higher than normal, causing permanent damage to the retina
331
glial cell
cell that helps support and insulate nerve tissue
332
gliding joint
joint in which one bone merely slides across the surface of another
333
globulin
any of a broad group of blood proteins that help transport fat throughout the body and fight infections
334
glucagon
pancreatic hormone that signals the liver to convert glycogen to glucose and release the glucose into the bloodstream
335
glucose
simple sugar produced by photosynthesis (C_6H_12O_6)
336
gluteus maximus
muscle that pulls the upper leg downward
337
Golgi apparatus
organelle that serves as a shipping center of a cell
338
gonad
reproductive organ of a human or animal that produces gametes
339
grafting
process of transplanting living tissue from one plant to another
OR
light and dark streaks in wood formed by differences in the size of springwood and summerwood vessels
340
grain
fruit of a grass plant
341
graminoid
general term for a member of the grass family
342
gray matter
portion of the brain and spinal cord that consists largely of neuron cell bodies
343
guard cell
either of a pair of crescent-shaped cells that expand and contract to open and close a stoma
344
gulfweed
common name for the brown algae of the genus Sargassum
345
gymnosperm
plant that does not produce flowers but does produce seeds
346
habitat
region where a particular organism normally lives; the organism's environment or home
347
hamstrings
group of three muscles in the back of the thigh that bend the leg at the knee
348
hardwood
another term for a broadleaf tree
349
head
flower cluster of a member of the composite family, which superficially resembles a single flower
350
heart
pump that propels blood through the circulatory system
351
heart attack
type of heart failure caused by a blockage of blood flow to the heart muscle
352
heart murmur
abnormal rushing or blowing heart sound produced by valve damage
353
heartbeat
"lub-dup" sounds produced by the heart during the cardiac cycle
354
heartwood
inner portion of a woody stem, made of older xylem tubes that have become clogged and been sealed off
355
hemisphere
right or left half of the cerebrum or cerebellum
356
hemoglobin
iron-containing blood protein, found in red blood cells, that carries oxygen in the blood
357
hemophilia
recessive sex-linked disease in which clots cannot form due to a hereditary defect in any of several blood-clotting proteins
358
herb
herbaceous plant
359
herbaceous
nonwoody
360
heteroecious
refers to a parasite that must have two hosts to complete its life cycle
361
heterotroph
organism that cannot produce its own food and must obtain energy from organic sources; also called a consumer
362
hinge joint
joint that allows a bone to move back and forth in a single plane
363
holdfast
special type of anchoring cell found in certain types of algae
364
homeostasis
condition of having and maintaining a stable internal environment, as in an individual cell or in the body as a whole
365
hormone
chemical produced by humans, plants, or animals to control or stimulate specific processes and regulate body activities; produced by the endocrine glands in humans and animals
366
horsetail
spore-producing vascular plant with unique hollow, jointed stems and very small leaves
367
horticulturist
agricultural technician who specializes in growing flowers, fruits, vegetables, and shrubs
368
human anatomy and physiology
study of the physical structure and function of the human body
369
humerus
upper-arm bone
370
husk
outer layer of a wheat kernel; also called chaff
371
hybrid
organism resulting from a cross between two different species of teh same kind of plant or animal
372
hydrochloric acid
component of gastric juice that softens food, kills bacteria, reacts with certain minerals to make them soluble, and provides the acid medium required for the enzyme pepsin
373
hydrogenated oil
vegetable oil with hydrogen added to change it from liquid to solid or semisolid
374
immune system
body system that defends against bacteria, viruses, and other invaders
375
hydroxyapaptite
rigid mineral that gives bones its hardness [Ca_10(PO_4)(OH)_2]
376
impacted
describes a tooth (usually a wisdom tooth) that has erupted too close to the adjacent tooth and become stuck
377
hyoid bone
U-shaped bone that is the foundation of many of the tongue muscles and of certain muscles involved in swallowing
378
incisor
any of the four front cutting teeth on each jaw
379
hypertension
condition in which resting blood pressure exceeds either 140 mmHg sytolic or 90 mmHg diastolic; also called high blood pressure
380
incomplete flower
flower that lacks one or more of the four basic flower parts
381
hypertrophy
enlargement of muscles through use
382
hyphae
threadlike filaments that form the body of a fungus
383
hypothalamus
portion of the limbic system that controls the autonomic nervous system and endocrine system and is responsible for the physical effect of emotions
384
incus
second bone of the middle ear; also called anvil
385
ileum
third and longest section of the small intestine
386
inferior vena cava
vein that returns blood from the lower part of the body to the heart
387
inflorescence
flower cluster
388
influenza
viral respiratory disease that causes fever, aching muscles, headache, and chest pain
389
inhalation
process in breathing in which air rushes into the lungs due to decreased pressure
390
inner ear
portion of the ear that is the actual organ of hearing
391
insectivorous plant
plant that uses special leaves to trap and digest small insects
392
insulin
pancreatic hormone that signals the liver and muscles to remove glucose from the blood and store it as glycogen
393
intercostal muscles
gruop of muscles located between the ribs; lift the rib cage to aid breathing
394
internal respiration
exchange of oxygen and carbon dioxide between blood cells and tissue cells
395
interneuron
neuron that relays signals between neurons or groups of neurons and is involved in information processing
396
internode
portion of a stem between nodes
397
interphase
stage of the cell cycle between cell divisions
398
interstitial fluid
fluid that fills the area around and between tissues
399
intervertebral disk
disk of flexible cartilage between vertebrae
400
intestinal glands
digestive glands in the small intestine that produce intestinal juice
401
intracellular fluid
fluid inside the body's cells
402
involuntary muscles
cardiac and smooth muscles
403
iris
front-most muscular portion of the uvea, which forms the colored portion of the eye and controls the size of the pupil
404
irregular bone
bone that cannot be easily classified as a long bone, short bone, or flat bone
405
jejunum
middle section of the small intestine
406
joint
place where bones join
407
kelp
any of the group containing the largest brown algae
408
kilocalorie
unit of energy sometimes used in physics, equal to one food Calorie
409
kind
group of similar organisms that are all descended from a single group of originally created organisms
410
kingdom
one of the main groups into which all organisms are divided in the Linnaean system of classification
411
lacrimal gland
tear gland
412
lacteal
tubelike lymph vessel that carries absorbed fats out of a villus
413
large intestine
tubelike organ that prepares undigested food for expulsion from the body
414
laryngeal muscles
muscles in the larynx that move the vocal cords
415
larynx
special enlargement of the trachea in which speech originates; also called voice box
416
lateral bud
bud that allows growth of a new stem from the side of the main stem; also called axillary bud
417
lateral root
root that originates from the taproot; also called secondary root
418
latissimus dorsi
muscle that connects the humerus to the lumbar region of the spine and pulls the arms to the rear
419
layering
method of vegetative propagation that involves causing an existing plant to generate adventitious roots at a node
420
leaf hair
one of the hairlike structures that cover the epidermis of certain plant leaves
421
leaf scar
scar left on a stem where a leaf was previously attached
422
leaflet
one of the small blades of a compound leaf
423
legume
plant of the pea family; a simple fruit consisting of a pod enclosing several seeds, which is characteristic of members of this family
424
lens
portion of the eye that focuses the rays of light
425
lenticel
opening in the bark of a stem that allows air to enter the stem
426
leukemia
form of cancer in which white blood cells are produced in uncontrolled numbers
427
lichen
single unit formed by a fungus and an alga living in close relationship
428
ligament
tissue that joins bones to other bones
429
limbic system
collective term for the brain structures, clustered around the brain stem, that coordinate the activity of the parts of the brain and seem to be involved in emotions
430
Linnaeus, Carolus
Swedish naturalist who devised the modern system of biological classification
431
lipid
any of a group of macronutrient compounds that are characterized by their insolubility in water
432
liver
large abdominal organ that functions as the body's chemical factory; produces bile; filters blood; and stores glycogen, vitamins, minerals, and reserve blood
433
liverwort
bryophyte that grows along the surface of the soil and often looks like tiny leaves
434
lobe
any of the main regions into which the hemispheres of the cerebrum are divided
435
long bone
bone longer than it is wide
436
lumbar
of or related to the lower back
437
lumbar vertebra
any of the five vertebrae of the lower back
438
lung
either of the two large, spongy organs that are the primary organs of the respiratory system
439
lysosome
special type of vesicle that functions as a recycling center
440
lysozyme
enzyme, found in tears, that kills bacteria by destroying their cell walls
441
macronutrient
any of the group of nutrients, consisting of carbohydrates, proteins, and fats, that are needed in relatively large amounts
442
malleus
first bone of the middle ear; also called hammer
443
margin
edge of a leaf blade
444
masseter
muscle that, with the temporalis, connects the mandible to the cranium and helps close the jaw
445
mastication
chewing
446
matrix
material surrounding cells in a tissue
447
maturation region
region of a root where cells organize into the vascular cylinder
448
mechanical dispersal
seed dispersal in which fruits scatter their seeds by bursting open and catapulting the seeds to a new location
449
mechanoreceptor
any of a group of sensory receptors responsible for sensations of touch and pressure and for muscle sense
450
medulla oblongata
lowest part of the brain stem; monitors and regulats various vital body functions
451
medullary cavity
cavity in the diaphysis of a long bone that stores red marrow (in infants and children) or yellow marrow (in adults); also called marrow cavity
452
membrane skeleton
network of flexible reinforcement fibers found beneath a cell membrane
453
meninges
triple layer of protective tissues surrounding the brain and spinal cord
454
meningitis
inflammation and swelling inside the skull, usually caused by an infection
455
meristematic region
region near the tip of a root where cell division takes place
456
meristematic tissue
plant tissue responsible for the growth and repair of plants
457
mesophyll
middle portion of a leaf, where most of the photosynthesis takes place
458
metabolism
general term for the chemical processes of life
459
metacarpal
any of the five bones that form the base of the hand and the palm
460
metaphase
second phase of mitosis, in which the spindle apparatus attaches to the replicated chromosomes and pulls them to the equatorial plane of the cell
461
metatarsal
any of the five bones that form the framework of the instep and the ball of the foot
462
micronutrient
any of the group of nutrients, consisting of vitamins and minerals, that are needed in relatively small amounts
463
microtubule
hollow, rodlike filament composed of tubulin
464
microvilli
fine extensions of the cell membrane on epithelial cells of the small intestine
465
midbrain
region of the brain stem above the pons; helps coordinate eye movements, adjust pupil size, and operate the lens muscles
466
middle ear
chamber containing the malleus, incus, and stapes
467
midrib
large vein running down the center of a leaf blade; major vein of a leaf with pinnate venation
468
mineral
inorganic nutrient
469
mint family
family of plants that has square stems and whose members are often very aromatic
470
mitochondrion
organelle that serves as the power plant of a cell; plural mitochondria
471
mixed nerve
nerve that includes both sensory and motor fibers
472
molar
any of the six heavy grinding teeth (three to a side) at the back of each jaw
473
monocot
plant with only one cotyledon per seed; typically characterized by flower petals that are arranged in groups of three, leaves that are usually long and narrow with parallel venation, and a fibrous root system
474
monoecious
having staminate and pistillate flowers produced by the same plant
475
moss
nonvascular spore plant that undergoes alternation of generations
476
motor area
portion of the frontal lobe that controls voluntary movement of skeletal muscles
477
motor nerve fiber
axon that carries impulses from the brain and spinal cord to muscles and organs
478
motor neuron
neuron that relays signals from the central nervous system to the other parts of the body
479
motor unit
motor neuron and the group of muscle cells it controls
480
mucous membrane
type of membrane that lines openings to the outside
481
mucus
slimy substance that lubricates the mucous membrane of the oral cavity
482
multiple fruit
fruit that forms from several flowers
483
multiple sclerosis
disease that occurs when the body's immune system attacks the glial cells that provide myelin sheaths for central-nervous-system axons
484
muscle fiber
individual muscle cell of a skeletal muscle
485
muscle sense
the brain's total awareness of body movements
486
muscle tissue
tissue that moves the body and its parts
487
muscular system
body system that functions together with the skeletal and nervous systems to make body movements possible
488
mushroom
club fungus that consists of a mass of subterranean hyphae and, at reproduction, produces an umbrella-shaped fruiting body
489
mycelium
mass of hyphae forming the main body of a fungus
490
myelin
white, specialized covering found on axons of nerve cells
491
myocardium
middle layer of the heart, containing the actual heart muscle tissue
492
myofibril
long cylinder inside a muscle fiber that contains the contraction machinery
493
nasal cavity
cavity inside the nose that warms, moistens, and filters air
494
nasal meatus
irregularly shaped pocket in the nasal cavity
495
nearsightedness
ability to see only near objects clearly due to the lens being too thick or the eye being too long; also called myopia
496
neck (oral cavity)
part of a tooth at the gum line
497
nectar
sweet-tasting, watery liquid produced by plants
498
nerve
bundle of nerve fibers (axons) branching from the brain and spinal cord
499
nerve center
group of nerve cell bodies in the brain or spinal cord
500
nerve tissue
tissue that cotnrols organs and coordinates their functions
501
nervous system
body system that coordinates the activities of the body
502
neuritis
degeneration and inflammation of nerves
503
neurobiologist
biologist who studies the nervous system
504
neurologist
physician who specializes in disorders of the nervous system
505
neuromuscular junction
point at which a neuron connects to a muscle cell
506
neuron
nerve cell
507
neurotransmitter
chemical released into a synapse by a neuron to cause an action in the receiving cell (e.g. making a muscle contract or a neuron fire)
508
night blindness
condition in which the eyes do not become adjusted to darkness
509
nitrate
any of the special compounds of nitrogen and oxygen that plants can use to make proteins
510
nitrifying bacteria
bacteria that provide nitrates to the soil from decomposing plants and animals
511
nitrogen cycle
biogeochemical cycle involving the movement of nitrogen from the air, into the soil, and back into the air
512
nitrogen-fixing bacteria
bacteria that grow on the roots of legumes and convert nitrogen in the air into ammonia and nitrates
513
node
one of the points at which leaves grow from the stem
514
nonseed plant
any vascular plant that does not reproduce using seeds
515
nonvascular plant
any nonseed plant that does not have vascular tissue
516
nuclear envelope
double-layered structure that separates the nucleus from the rest of the cell
517
nuclear pore
large protein complex in the nuclear envelope that serve as a gate to regulate the transport of large molecules into and out of the nucleus
518
nucleolus
distinct region within the nucleus that assembles ribosomes
519
nucleus
"control center" of a cell, which stores the DNA
520
nut
simple dry fruit consisting of a seed enclosed in a hard shell
521
obesity
being severely overweight due to excess body fat
522
occipital lobe
lobe of the cerebrum corresponding to the occipital bone; associated with vision
523
oil
fat that is liquid at room temperature
524
olfactory nerve
nerve connecting the nose's sensory receptors to the brain
525
opposite (plants)
leaf pattern in which two leaves grow from each node
526
optic nerve
nerve that connects the eye to the brain
527
oral cavity
inside of the mouth
528
order
level of classification between class and family
529
organ
structure within a system that has a definite form and performs a definite function or functions for the system
530
organelle
"little organ" within the cytoplasm of a cell
531
organism
individual living thing
532
osmosis
one-way diffusion through a semipermeable membrane
533
ossification
process by which cartilage is replaced with bone
534
osteoblast
cell that moves through a Haversian canal, constructing new collagen fibers and hydroxyapatite crystals
535
osteoclast
cell that continually moves through a bone removing old material
536
outer ear
portion of the ear consisting of the visible sound-collecting structure and the ear canal
537
ovary
swollen base of a pistil; contains ovules
538
ovulate cone
cone that produces seeds; also called seed cone
539
ovule
one of a plant's future seeds, which contain the female reproductive cells
540
pain receptor
any of a group of sensory receptors that consist of a bare dendrite activated by extreme heat or cold, excessive mechanical stress, damage to body cells, etc.
541
palate
structure that forms the roof of the mouth
542
palmate venation
leaf venation in which two or more major veins extend outward from one point
543
pancreas
organ that produces pancreatic juice and contains the islets of Langerhans
544
pancreatic juice
digestive juice, produced by the pancreas, that contain digestive enzymes needed in the small intestine
545
papillae
taste-bud-containing projections on the tongue
546
parallel venation
leaf venation in which the veins are usually parallel to each other along the length of the leaf
547
paralysis
inability of muscles to move
548
parasite
organism that lives on or in another living organism and derives its nutrition from that organism
549
parasympathetic division
portion of the autonomic nervous system that counteracts the sympathetic division
550
parenchyma
plant structural tissue that makes and stores food
551
parietal lobe
lobe of the cerebrum corresponding to the parietal bones; analyzes senses to feel temperature, pressure, pain, shape, and texture
552
Parkinson's disease
disease characterized by tremors and stiffness of the limbs that appears to result from a lack of dopamine
553
passive transport
movement of molecules across the cell membrane from a place of higher concentration to a place of lower concentration without the expenditure of energy
554
patella
kneecap
555
peat
compressed accumulation of various partially decayed plant materials that collect in swamps and marshes
556
peat moss
large, branching type of swamp-dwelling moss that helps prevent soil erosion and has antiseptic qualities
557
pectoral girdle
collective term for the shoulder bones, which attach the arms to the axial skeleton
558
pectoralis major
largest chest muscle; pulls arms forward
559
pedicel
special stem on which a flower forms; flower stalk
560
pelvic bone
either of the two large, heavy bones that attach to the sacrum and form most of the pelvic girdle
561
pelvic girdle
collective term for the bones that form the hips and attach the legs to the axial skeleton
562
pelvis
another name for the pelvic girdle
563
peptic ulcer
ulcer caused by the digestive action of pepsin; includes both gastric and duodenal ulcers
564
perennial
plant that lives from year to year and blooms each season
565
pericardium
tough, white sac in which the heart is encased
566
periodontitis
periodontal disease in which the gums detach from the teeth and eventually the bones supporting the teeth are destroyed
567
peripheral nervous system
portion of the nervous system that consists of nerves
568
peristalsis
rhythmic wave of muscular contractions that moves food through the digestive tract
569
permanent wilting
wilting that occurs when there is a drought and there is not sufficient soil water to replace that lost by transpiration; results in the loss of leaves and possibly the death of the plant
570
persistence of vision
phenomenom in which an object's image on the retina persists for about 1/10 second after the object is gone
571
petal
most conspicuous part of a flower
572
petiole
part of a leaf that attaches the blade to the stem
573
phalanx
any of the bones of the fingers and toes; plural phalanges
574
pharynx
throat
575
phloem
plant vascular tissue that transports food manufactured in the leaves downward
576
phospholipid
special type of lipid molecule of which the cell mebrane is composed
577
photoperiodism
phenomenom in which a plant requires a definite period of light and darkness before it will flower
578
photosynthesis
process whereby a plant's chloroplasts capture the radiant energy of light and convert it into the chemical energy of food
579
phototropism
growth response of a plant to move toward light
580
phylum
one of the main groups into which a kingdom is divided; also called a division in botany; plural phyla
581
pinnate venation
leaf venation in which the veins are in a branching pattern characterized by a midrib with smaller veins extending out from it
582
pinocytosis
form of endocytosis involving the intake of liquids
583
pistil
elongated, vase-shaped structure of a flower that contains the female reproductive structures
584
pistillate
describes a female flower, which lacks stamens and bears only pistils
585
pith
water-storage region at the center of a young woody stem
586
pivot joint
joint in which one bone rotates in place against another bone
587
plankton
collective term for microorganisms that float near the surface of the water and provide food for larger organisms
588
Plantae
plant kingdom; consists of multicellular eukaryotes that have cell walls and usually perform photosynthesis (green plants)
589
plaque
sticky, colorless film of bacteria that forms on and between teeth
OR
deposit of fatty material and calcium formed on the inside of an artery
590
plasma
straw-colored liquid part of the blood
591
platelet
tiny disk-shaped cell fragment that helps patch blood vessels during clotting
592
pleura
double membrane that provides lubrication between the ribs and the surface of the lungs
593
pleurisy
inflammation of the pleura
594
plexus
large mass of ganglia grouped together
595
plumule
tiny shoot within a seed that will develop into the shoot system
596
pneumonia
bacterial or viral infection of the linings in the lungs that cause the lungs to secrete large quantities of fluid
597
poliomyelitis
disease caused by a virus that attacks motor neurons of the spinal cord, paralyzing muscles connected to the brain by these neurons
598
pollen
plant reproductive structure, produced by the anther of the stamen, that contains the sperm cells
599
pollen tube
tube formed by a pollen grain through which the sperm cells reach the ovule
600
pollination
transfer of pollen from an anther to the stigma of a pistil
601
pome
simple fruit with an outer fleshy layer and an inner papery core
602
pons
portion of the brain stem that links the cerebrum and cerebellum; assists the medulla oblongata in regulating breathing and helps coordinate some eye movements and facial expressions
603
portal circulation
portion of systemic circulation in which blood moves from the digestive organs and spleen to the liver
604
presbyopia
inability to focus on near objects as the lens becomes less elastic with age
605
primary color
any of the three colors corresponding to those absorbed most strongly by the three different types of cone cells
606
primary growth
growth of a stem in length
607
primary odor
any of the seven basic odors of which all other odors are thought to be composed
608
primary root
root that grows directly from the plant embryo; taproot
609
prokaryote
organism that does not have a membrane-bound nucleus
610
prophrase
first stage of mitosis, in which the cell packages the chromosomes, forms the spindle apparatus, and dismantles the nucleolus and nuclear envelope
611
protein
any of a group of complex organic molecules used to build and maintain living cells; made of a long chain of amino acids
612
Protista
kingdom consisting of eukaryotes that are not green plants, fungi, or multicellular animals
613
Protococcus
type of sehprical, unicellular green alga that often grows on the trunks of trees and on unpainted buildings and fenceposts
614
protoplasm
gel or slime of which cells were thought to consist before modern discoveries of cell complexity
615
pulmonary artery
either of two blood vessels that carry deoxygenated blood from the heart to the lungs
616
pulmonary circulation
movement of blood between the heart and the lungs
617
pulmonary semilunar valve
heart valve that allows blood to exit the right ventricle and enter the pulmonary arteries
618
pulmonary vein
either of two pairs of blood vessels that carry oxygenated blood from the lungs back to the heart
619
pulp
inner part of a tooth consisting mainly of blood vessels and nerves
620
pulse
rhythmic blood-pressure changes in the arteries as the heart beats
621
pupil
opening through which light enters the eye
622
pyloric sphincter
muscle structure that opens and closes to control the movement of food from the stomach to the small intestine
623
quadriceps femoris
group of four muscles in front of the thigh that straighten the leg at the knee
624
radicle
portion of a plant embryo that develops into the root system
625
radius
bone of the forearm on the same side as the thumb
626
Ray, John
17th-century English clergyman and naturalist who introduced a precise concept of species, wrote books on plants, and described how man can learn of God's power by studying His creation
627
ray flower
one of the petal-like flowers arranged around the edge of a composite flower head
628
receptacle
enlarged end of a pedicel, designed to hold the devolping seeds
629
rectum
section of the large intestine that stores feces until they are expelled from the body
630
rectus abdominis
group of muscles extending from the bottom of the sternum to the front of the pelvic girdle
631
red blood cell
blood cell that carries oxygen in hemoglobin molecules; also called erythrocyte
632
red fiber
muscle fiber that contains many mitochondria and large amounts of myoglobin
633
red marrow
special tissue, found in bones, that manufactures red blood cells and white blood cells
634
red tide
phenomenom that occurs when a certain dinoflagellate blooms, producing great quantities of a highly toxic nerve poison
635
reflex
quick, automatic response
636
reflex arc
nerve pathway controlling a reflex, which allows nerve impulses to bypass the brain for a speedy response
637
region of elongation
region in a root where cells increase in length
638
REM sleep
period of sleep in which the eyes move rapidly as if they were watching the events of a dream
639
renal circulation
portion of systemic circulation in which blood moves through the kidneys
640
reproduction system
body system that carries out the process of reproduction and is responsible for the continuation of the human race
641
respiratory system
body system that takes oxygen into the body and releases carbon dioxide from the body
642
reticular formation
intricate network of neurons within the brain stem that serves as the "master switch" of the cerebrum
643
retina
light-sensitive innermost layer of the eye
644
Rh blood group
red-blood-cell antigen group whose most important member is the Rh factor
645
Rh factor
most important antigen in the Rh blood group
646
rhizoid
hairlike thread that acts as a bryophyte "root"
647
rhizome
thick stem that grows horizontally underground to provide food storage and cause vegetative reproduction, such as the underground stem of a fern
648
rhodopsin
light-absorbing substance in rod cells
649
rib
long, curved bone that attaches to the thoracic vertebrae in back and to the sternum in front
650
ribosome
cell structure that performs translation to manufacture proteins based on mRNA "blueprints" from the nucleus
651
rickets
childhood disease in which the bones are weak and deformed due to vitamin D deficiency
652
rind
outer covering of a monocot stem
653
ripening
process in which a flower ovary grows larger and develops into a fruit
654
rockweed
brown alga that lives attached to rocks along the seashore and has gas-filled air bladders that serve as floats
655
rod
type of cell in the retina that detects light of all colors
656
root
part of a plant that is ordinarily underground, anchoring the plant, and that functions in absorption of nutrients and storage of food
OR
part of a tooth that anchors it below the gum
657
root cap
cone-shaped structure that covers and protects the tip of a plant root
658
root cortex
region of a plant root where food is stored
659
root hair
fingerlike projection of epidermal cells that increases the water-absorbing surface area of a plant root
660
rosette
leaf pattern in which a cluster of leaves grows around the base of the plant; also called a basal arrangement
661
rust
any of a group of parasitic club fungi that leave rusty-colored spores on their hosts
662
sac fungi
group of fungi with saclike spore-producing structures
663
sacral vertebra
any of the five vertebrae (fused into the sacrum in adults) that are joined rigidly to the hip bones; also called pelvic vertebra
664
saddle joint
joint in which a saddle-shaped portion of one bone nestles into a saddle-shaped portion of another bone
665
saliva
sticky digestive juice produced by the salivary glands
666
salivary amylase
digestive enzyme produced by the salivary glands that begins the digestion of starch
667
salivary gland
any of the six saliva-secreting digestive glands of the mouth
668
salmonellosis
common food infection caused by bacteria of the genus Salmonella
669
samara
fruit consisting of a small dry seed with one or more winglike structures attached to it
670
sap
sweet liquid found within the vascular tissue of plants
671
sap stream
upward flow of water and minerals through the xylem
672
saprophyte
organism that obtains nutrition from dead organisms
673
sapwood
younger, functioning xylem tissue found in the outer portion of a woody stem
674
sarcomere
repeated unit within a myofibril, consisting of overlapping protein fibers that give skeletal muscle its striated appearance
675
sartorius
muscle that extends diagonally downward from the front of the pelvic bone and passes around the side of the thigh to connect it to the tibia; lifts the lower leg and turns it inward
676
saturated fatty acid
fatty acid in which every possible bond to hydrogen is occupied
677
scab
fibrin and platelet structure formed by a blood clot on the surface of the skin
678
scapula
shoulder blade
679
Schwann cell
type of glial cell that produces layers of myelin sheathing on nerves in the peripheral nervous system
680
sciatica
condition, characterized by pain in the lower back and the back of the thigh, caused by a pinching of the sciatic nerve
681
scion
branch that will be grafted onto a stem growing on another tree
682
sclera
tough outer layer of the eye; the white of the eye
683
scoliosis
severe lateral curvature of the spine
684
seaweed
large seawater alga
685
secondary bronchi
branches into which a bronchus divides after entering the lungs
686
secondary growth
growth of a stem in width
687
seed
fully developed and mature ovule that can produce a new plant
688
seed coat
protective covering of a seed
689
seed plant
any vascular plant that produces seeds (an angiosperm or gymnosperm)
690
self-pollination
pollination that occurs within a flower
691
semicircular canals
assembly of fluid-filled tubes in the inner ear that serve as balance sensors
692
semilunar valve
either of the two heart valves that allow blood to flow to the body from the ventricles
693
senile dementia
disorder that results from the slow process of natural nerve cell loss
694
sense organ
intricately designed organ for a special sense
695
sensorineural deafness
partial or complete hearing loss caused by repeated or prolongued exposure to excessively loud sounds
696
sensory nerve fiber
axon that carries sensory impulses to the spinal cord and brain
697
sensory neuron
neuron that transmits information from the senses to the central nervous system
698
sensory receptor
specialized neuron that obtains sensory information and relays it to the brain and spinal cord
699
sepal
leaflike structure attached to the edge of a flower's receptacle
700
septum
thick vertical wall dividing the left and right sides of the heart
701
serous membrane
type of membrane that lines enclosed body cavities that do not open to the exterior
702
sessile
describes a leaf that lacks a petiole
703
sexual reproduction
form of reproduction in which genetic material is contributed by two parents through the union of sperm and egg
704
sheath
bottom portion of a grass leaf, which wraps partially around the stem
705
shelf fungi
group of shelflike club fungi that grow slowly and do not have gills; also called bracket fungi
706
shoot system
the part of the plant that is usually found above ground, holding the leaves toward the sun for the manufacturing of food and providing for the production of flowers, fruits, and seeds
707
short bone
bone that is roughly cube shaped
708
shrub
plant that has several low, woody stems near the ground and can stand without support
709
sickle cell anemia
genetic disease that causes hemoglobin molecules to clump together, making red blood cells brittle and sickle shaped under certain conditions
710
sieve plate
perforated plate at the end of a woody-stem phloem cell
711
sieve tube
phloem cells connected end to end at the sieve plates to conduct food through a woody plant
712
silica
hard substance in sand, glass, and diatom cell walls; chemical formula SiO_2
713
simple carbohydrate
either a monosaccharide or disaccharide
714
simple fracture
fracture in which the bone cracks or breaks but does not pierce through the skin; also called closed fracture
715
simple fruit
fruit that forms from a flower that has only one pistil
716
simple leaf
leaf that has one blade on every petiole
717
sinoatrial node
portion of the cardiac conduction system that functions as the heart's pacemaker; also called S-A node
718
sinus
hollow space within the design of a skull bone
719
skeletal muscle
any muscle whose primary function is to move the parts of the skeleton
720
skeletal system
body system that provides support and rigidity and serves as the framework of the body
721
skull
bones forming the structure of the head
722
slime mold
jellylike organism that oozes into its environment to engulf bacteria and other particles
723
small intestine
long, tubular organ that is the primary organ of digestion and absorption
724
smooth muscle
involuntary muscle tissue used to perform functions such as operating sphincters, adjusting tension in blood-vessel walls, squeezing food through the alimentary canal, and adjusting the focus of the lenses in the eyes
725
smut
any of a group of parasitic club fungi that produce masses of black spores on their hosts
726
socket
portion of the skull that protects the eye by surrounding it with heavy bone; also called orbit
727
sodium bicarbonate
chemical produced by the pancreas to neutralize stomach acid in chyme that enters the small intestine
728
somatic sense
any of the senses that detect touch, temperature, pain, etc.
729
sorus
small, brownish dot on the underside of a fern frond that contains spore cases; plural sori
730
special leaf
leaf that has a special design for a special task; also called a modified leaf
731
special sense
any of the senses that are provided by neurons in sense organs
732
species
group of very similar organisms that can interbreed freely in nature; lowest of the seven main levels of the Linnaean classification system
733
sperm cell
male reproductive cell
734
Sphagnum
genus of peat moss
735
spinal cavity
body cavity containing the spinal cord
736
spinal cord
thick bundle of nerve fibers within the spinal cavity by which the brain communicates with most of the body
737
spinal nerve
any of the thirty-one pairs of nerves that branch from the spinal cord
738
spindle apparatus
structure, consisting of centrosomes and microtubules, that pulls chromatids apart during mitosis
739
spine
special protective leaves that have no chlorophyll
740
spirelike branching
type of branching in which a tree grows tall and straight with branches coming from a large central stem
741
spirogyra
filamentous green alga characterized by ribbonlike chloroplasts arranged in a spiral
742
spleen
hand-sized lymphatic organ that holds a large emergency supply of blood and red blood cells; cleans the blood of microbes; and works with the liver to destroy old, worn-out red blood cells
743
spongy bone
lightweight, porous tissue composing the interior of a bone's epiphyses
744
sporangium
spore case of a fern; plural sporangia
745
spore
tiny, one-celled reproductive structure that can grow into a distinct or independent organism under the proper conditions
746
sporophyte
asexually reproducing generation in alternation of generations
747
sprain
injury that occurs when the ligaments of a joint are overstrained
748
spreading branching
type of branching in which a tree develops several main branches, usually close to the ground
749
stamen
pollen-producing organ within a flower
750
staminate
describes a male plant reproductive structure that produces only pollen, such as a flower that lacks a pistil and has only stamens or a pollen-producing cone
751
stapes
second bone of the middle ear; also called stirrup
752
starch
mixture of long, chainlike molecules that consist of thousands of glucose molecules linked together, manufactured by plants for glucose storage
753
sternocleidomastoid
muscle that connects the temporal bone to the sternum and clavicles; moves head forward and helps turn the head from side to side
754
sternum
breastbone
755
stigma
tip of the pistil, which receives pollen grains during pollination
OR
eyespot of certain green algae
756
stock
tree that receives a new stem by grafting
757
stolon
creeping special stem that grows above the ground and produces new plants wherever a node touches the soil; common in grass plants; also called a runner
758
stoma
tiny opening in the surface of a leaf that allows gases to enter and leave the leaf; also called leaf pore; plural stomata
759
stomach
muscular digestive organ that thoroughly mixes food with digestive juices
760
stone
inner woody layer of a drupe
761
striated muscle
muscle tissue that has a striated (striped) appearance under the microscope; skeletal and cardiac muscle tissue
762
stroke
death of brain tissue caused by internal blockage or rupture of a blood vessel in the brain
763
structural tissue
type of tissue that composes most of the body of a plant
764
style
stalklike portion of a pistil, which connects the ovary to the stigma
765
sucrose
table sugar
766
sugar
any of a group of small carbohydrates
767
superior vena cava
vein that returns blood from the upper part of the body to the heart
768
support and strengthening tissue
plant structural tissue consisting of fibers that run through roots, stems, and large veins of leaves
769
suture
jagged joint line that connects cranial bones tightly
770
symbiosis
close relationship between two different species over a period of time, especially one in which they mutually benefit
771
sympathetic division
portion of the autonomic nervous system that responds to increased activity and emergency situations
772
synapse
enclosed junction between two neurons or a neuron and another cell
773
synovial fluid
lubricating fluid inside a freely movable joint
774
synovial mebrane
type of membrane that lines the joint cavities
775
system
group of structures designed to function together as a unit to perform a particular job for an organism's body
776
systemic circulation
movement of blood through all parts of the body except the lungs
777
systole
contracting and pumping phase of heart action
778
taproot
root system in which the primary root grows straight down and remains larger than the secondary roots that branch off from it, penetrating the soil with relatively little branching
779
tarsal
any of the seven bones of the ankle and heel
780
tartar
hard deposit on teeth formed by plaque not removed by daily brushing and flossing; medically called calculus
781
taste bud
organ of taste, consisting of chemoreceptors for different types of taste
782
taxonomy
process of arranging organisms into group based on similarities
783
tear
fluid secreted by the lacrimal glands to clean and moisten the eye
784
telophase
fourth and final stage of mitosis, in which the chromosomes are unpacked and the nuclear envelope and nucleolus reform
785
temporal lobe
lobe of the cerebrum corresponding to the temporal bones; associated with senses of hearing, taste, and smell
786
temporalis
muscle that, with the masseter, connects the mandible to the cranium and helps close the jaw
787
temporary wilting
wilting that occurs when transpiration takes place faster than the roots can absorb soil water; plant recovers at night, when transpiration is reduced
788
tendon
strong "cable" of fibers that attaches a muscle to a bone
789
tendril
special leaf or stem that has the unique function of holding a plant upright by coiling around some support structure
790
terminal bud
bud that allows a stem to grow in length; also called apical bud
791
tetanus
disease produced by the soil bacterium Clostridium tetani, whose toxin damages motor nerves, resulting in death if untreated; also called lockjaw
792
thalamus
structure in the limbic system that acts as a switchboard, routing signals to the appropriate area of the cerebral cortex
793
thermoreceptor
sensory receptor that responds to temperature changes
794
thoracic
of or related to the chest
795
thoracic cage
cagelike bone structure in the chest that protects the organs of the thoracic cavity
796
thoracic cavity
chest cavity, containing the heart, lungs, esophagus, trachea, thymus, and aorta
797
thoracic vertebra
any of the twelve vertebrae that are the attachments for the thoracic cage
798
thorn
long, sharp special stem that provides protection to a plant
799
thylakoid
one of the special chlorophyll-containing disks inside a chloroplast
800
tibia
main weight-bearing bone in the lower leg; the shin bone
801
tidal volume
volume of air inhaled and exhaled during normal breathing
802
tinnitus
ringing in the ears
803
tissue
group of similar cells that work together to form a particular task for an organ
804
tissue culturing
method of vegetative propagation in which seedlings are produced from individual plant cells grown in the laboratory
805
tongue
muscular organ that pushes food between the teeth, mixes it with mucus and saliva, and prepares chewed food for swallowing
806
tooth
structure in the mouth that cuts, breaks, or crushes food into smaller pieces
807
trace element
any of the mineral nutrients that are needed only in extremely small quantities
808
trachea
tube that carries air from the pharynx to the lungs; also called windpipe
809
tracheid
long, narrow, rod-shaped cell that helps conduct water in the xylem of a woody stem
810
transpiration
loss of water vapor from leaves and stems of a plant
811
transpiration pull
force that draws sap up a stem as leaf cells pull water into themselves
812
trapezius
muscle in the back of the shoulder; pulls the shoulders and head back and helps turn the head from side to side
813
tree
plant with a single tall, woody stem capable of standing erect without support
814
triceps brachii
muscle located in the back of the upper arm that extends the forearms; also called triceps
815
tricupsid valve
heart valve connecting the right atrium and right ventricle
816
triglyceride
another name for a fat
817
tropism
response in which an organism moves either toward or away from a stimulus
818
trunk
main stem of a tree
819
tuber
bud-containing special stem that grows underground to store food
820
tuberculosis
severe respiratory disease caused by infection with Myobacterium tuberculosis
821
turf grass
any of the grasses used as coverings for lawns, athletic fields, golf courses, and playgrounds
822
turgid
swollen, distended
823
turgor pressure
pressure produced by water within guard cells; causes stomata to open and close
824
typhoid fever
serious illness acquired from food or water contaminated with the bacteria Salmonella Typhi
825
ulcer
open sore in the mucous membrane of the digestive tract
826
ulna
bone of the forearm on the same side as the little finger
827
unsaturated fat
fat containing unsaturated fatty acids
828
unsaturated fatty acid
fatty acid in which the hydrogen-carbon chain can form one or more additional pairs of bonds to hydrogen
829
urea
waste substance made from excess amino acids
830
uterus
hollow muscular organ in a woman's lower abdomen that provides a place for an unborn child to develop; also called womb
831
uvea
middle layer of the eye
832
vacuole
structure in a cell that stores food materials, fluid substances, and minerals
833
valve
half a diatom's cell wall
OR
structure in the heart that pevents blood from flowing in the wrong direction
834
vascular bundle
bundle of xylem and phloem cells found in a herbaceous stem
835
vascular cambium
cambium tissue that produces new vascular tissue
836
vascular cylindar
innermost portion of a root, containing xylem and phloem; also called stele
837
vascular plant
any of the plants that have vascular tissue; also called tracheophyte
838
vascular ray
structure found in most mature trees that helps transport materials between the center and edges of the tree
839
vascular tissue
sap-conducting tissue of plants, composed of elongated, tubular cells
840
vegetative propagation
process of deliberately using vegetative reproduction to start a new plant
841
vegetative reproduction
formation of a new plant from a stem, leaf, or root
842
vein
one of the tubes running through the mesophyll of a leaf that contains the leaf's vascular tissue
OR
relatively thin-walled blood vessel that returns blood to the heart
843
venae cavae
two large veins that return deoxygenated blood from the body to the heart; sing. vena cava
844
venation
pattern of the veins within a leaf
845
ventricle
thick-walled lower chamber of the heart
846
ventricular fibrillation
type of heart failure in which the heart twitches randomly instead of beating
847
venule
small blood vessel connecting capillaries and veins
848
vertebra
bone of the vertebral column; plural vertebrae
849
vertebral column
chief structural member of the body, made of 33 vertebrae; the support to which all the other parts of the skeleton are attached; also called backbone, spinal column, and spine
850
vesicle
container within a cell that serves purposes such as transporting proteins
851
vessel
large water-conducting tube in the xylem of a woody stem
852
vestigal
describes organs that allegedly serve no useful purpose today
853
viable
able to germinate and grow
854
villus
tiny, hairlike projection of the small intestine that absorbs digested food; plural villi
855
vine
any plant with a long, thin stem that grows along the ground or has tendrils that twine around a wall or other support
856
viral hepatitis
liver infection that can be acquired by skin contact, contaminated food, blood transfusions, and intravenous drug use
857
viscera
general term for the soft internal organs within the thoracic and abdominal cavities
858
vital capacity
maximum volume of air that can be inhaled and exhaled
859
vitamin
any of a group of organic substances needed in small amounts for proper function of metabolism
860
vitreous humor
transparent, jellylike fluid that fills the space between the lens and the rear of the eye
861
vocal cords
structures in the larynx that vibrate to produce sound
862
voluntary muscle
any of the muscles that are generally under conscious control; a skeletal muscle
863
volvox
colonial green alga that lives in pale-green globular colonies containing hundreds or thousands of individual cells
864
water-soluble vitamin
any of the vitamins that are soluble in water and can be easily eliminated from the body
865
wheat rust
widespread rust fungus that lives on wheat and barberry bushes
866
whiplash
injury, caused by the body being jolted, to the spinal nerves that branch from the spinal cord in the neck
867
white blood cell
blood cell that functions as part of the immune system, helping the body fight disease; also called leukocyte
868
white fiber
muscle fiber containing fewer mitochondria and less myoglobin than red fibers
869
white matter
portion of the brain and spinal cord composed of axons and glial cells that are white because of their myelin content
870
whorled
leaf pattern in which three or more leaves grow from each node
871
wilting
effect of a high rate of transpiration on a plant
872
wisdom tooth
last molar on each side of the jaw
873
Wolff's law
principle that bones adjust their shapes to the physical stress placed upon them
874
Wollemi pine
unusual Australian conifer only known from fossils until a grove of living trees was discovered in 1994
875
wood
strong, relisient inner section of a woody stem
876
woody plant
plant that produces wood
877
xanthophyll
pigment in leaves that produces yellowish colors
878
xylem
plant vascular tissue that transports water and dissolved minerals upward from the roots to the leaves
879
yeast
small, colorless, single-celled sac fungus that feeds on cells containing sugar, converting the sugar into alcohol and carbon dioxide
880
yellow marrow
fat-storing tissue found in the diaphyses of adult bones
881
zoology
study of animals
