Terms Flashcards
theory vs. law
a law is a universal generalization related to how the natural world behaves under certain conditions. is testable, internally consistent, compatible with available evidence.
a theory is an explanation of a particular phenomenon of the natural world. explains aspects of laws, doesn’t become laws
Nature of scientific knowledge
Durability: withstands the test of time
Tentativeness: the development of new technologies/perseverance of continued observation and testing
Precision
when repeated measurements show the same results
Accuracy
how close a measurement is to the real/perceived value
Compound
when 2 or more different atoms bond together chemically to form a unique substance
Simple combination reaction
the reverse of a decomposition (A + B → C)
Replacement reaction
when 1 compound breaks apart and forms a new compound with a free reactant
1st law of thermodynamics
the law of conservation of matter and energy - matter and energy can neither be created nor destroyed
2nd law of thermodynamics
the law of increasing disorder/entropy - all reactions spread energy, which tends to diminish its availability
The cell theory
- All living things are made of 1 or more cells
- Cells are the basic units of life
- All cells come from preexisting cells
Smooth endoplasmic reticulum
network of membranous channels. Doesn’t have attached ribosomes. Responsible for processing lipids, fats, steroids; where are dispersed by the golgi apparatus
Light reaction (photolysis)
a decomposition reaction; chlorophyll a absorbs a photon of light and gets excited. Water molecules separated into their ions. O2 released as gas. H+ grabbed by H acceptor. Produces ATP from ADP and Pi
Dark reaction (carbon fixation)
in stroma of chloroplast. 6CO2 molecules linked with H from photolysis to form glucose, which is linked to form polysaccharides
Glycolysis
glucose (6C) + 2ADP + 2Pi+ 2NAD+ –> 2pyruvate (3C) + 2ATP + 2NADH+ + 2H+
Aerobic respiration
Krebs cycle: occurs in mitochondrial matrix. Breaks down pyruvate into CO2, H+, and 2ATP. Liberates electrons
Electron transport chain: series of cytochromes on cristae (protein + heme), either oxidized or reduced. Energy stored in ATP. produces 32 ATPs per glucose molecule. Last step occurs when H20 produced
Anaerobic respiration (fermentation)
breaks down 2 pyruvates into ethyl alcohol C3H6O3 plus CO2. gains 2 ATPs per molecule of glucose
Structural genes
code proteins that form organs/structural characteristics
Regulatory genes
code proteins that determine functional/physiological events (growth)
transduction vs. transformation
transduction: the transfer of genetic material from 1 bacterial cell to another, medicated by a bacteriophage
transformation: when 1 bacteria absorb/incorporate pieces of DNA from their environment (usually from dead bacterial cells)
nucleosomes
subunits that make long chains that form chromosomes
law of segregation
traits are expressed from a pair of genes in the individual (on homologous chromosomes)
law of dominance
one gene usually expressed itself over the other
law of independent assortment
homologous chromosomes separate independently during gamete formation
autosomal recessive disorders
ex. cystic fibrosis, sickle cell anemia. 2 inherited copies required
Rett syndrome and rickets
diseases caused by dominant mutation on the X chromosome
carrying capacity (K)
the limited no. of organisms that an ecosystem can support. once reached, competition occurs
gene pool
the entire collection of genes within a given population
allopatric speciation
when 2 populations are geographically isolated from each other
sympatric speciation
speciation without a geographic separation, when a population develops members with genetic differences which prevents successful reproduction with the original species
adaptive radiation
over time, species will specially adapt to live more efficiently in their new environment
punctuated equilibrium
speciation events are punctuated/interspersed with periods of relative stasis (as opposed to the older model - gradualism - which would predict smooth, continuous transitions)
balanced polymorphism
work in order to keep any particular version within a species from dominating, unless that particular version is fitter
oparian hypothesis
proposed that earth was 4.6 billion years old and that early earth had a reducing atmosphere (very little free O2 present) abundance of NH3, H+, CH3, and H20 escaping from volcanoes
homologous vs. analogous
homologous: strucures that exist in 2 different species because they share common ancestry
analogous: commonly functioning structures without common ancestry - the product of CONVERGENT evolution
altruism
social behavior where organisms place the needs of the community over their own needs
Linnaeus classification
domain -archaea -eubacteria -eukaryota ----protista ----fungi ----animalia ----plantae kingdom class order family genus species
9 phyla of kingdom animalia
porifera cnidaria platyhelminthes nematoda mollusca annelida arthropoda echinodermata chordata (fish, amphibians, reptiles, birds, mammals, lampreys) subphyla: --urochordata --cephalochordata --vertebrata
superclasses of vertebrata
agantha (no jaws) gnathostomata (jaws) 1. chondrichthyes 2. osteichthyes 3. amphibia 4. reptilia 5. aves 6. mammalia
chondrichthyes
fish with cartalagenous endoskeleton, 2 chambered heart, 5-7 gill pairs, no swim bladder/lungs, internal fertilization
ex. sharks, reys
mammalia
body covered with hair, glands, teeth, fleshy ears, 4 limbs, 4 chambered heart, lungs, larynx, developed brain, warm blooded, internal fertilization, live birth, milk producing
ex. cows, humans
sepals
small green leaf like structures which fold back to reveal flower petals (which are usually brightly colored to attract birds and insects to be pollinated)
pedicel
the short branch of the stem which supports the flower
female angiosperm
PISTIL includes:
stigma: sticky surface at top which traps pollen grains. sits above the style
style: encloses ovary
ovary: hollow, bulb shaped structure in lower interior of pistil - becomes fruit
ovules: small round cases within ovary that contain 1+ egg cells. during meiosis, egg & polar body formed which becomes endosperm when fertilized
male angiosperm
STAMEN includes:
anther on top of long hollow filament, which has 4 lobes with cells that become pollen
pollen grains conveyed to flower, stick to stigma
pollen tube: burrowing of pollen
nucleus: developed portion of pollen grain, produces tube
sperm nuclei: behind the tube nucleus. fertilization when they reach an egg cell. other fuses with polar bodies to form endosperm (feeds growing embryo)
shoot apex
composed of meristem tissue (undifferentiated cells that can quickly grow/specialize) and is where elongation occurs. the location of the terminal bud - the beginning of a new set of leaves. last year’s terminal bud is the terminal bud scar
seed
contains tiny embryonic plant, stored food, and seed coat for protection. germinates in the right conditions
amphibia
animal with bony skeleton, 4 limbs with webbed feet and 4 toes, cold blooded (ectothermic), large mouth/small teeth, 3 chambered heart, separate sexes, internal or external fertilization, amniotic egg
ex. salamander, frog
reptilia
horny epidermal scales, paired limbs with 5 toes, bony skeleton, lungs (no gills), 3 chambered heart, cold blooded (ectothermic), internal fertilization, separate sexes, egg laying (oviparious) - eggs with extra amniotic membranes
ex. snakes, lizards, alligators
aves
spindle shaped body, long neck, paired limbs, wings, 4 toed foot, feathers, leg scales, bony skeleton, bones with air cavities, beak, no teeth, 4 chambered heart, endothermic (warm blooded), lungs with thin air sacs, separate sexes, eggs with hard calcified shells
ex. birds, ducks, sparrows
kin selection
the tendency of an individual to be altruistic toward a close relative, resulting in preservation of genetic traits
osteichthyes
fish with bony skeleton, numerous vertebrae, swim bladder, 2 chambered heart, gills with bony gill and arches, external fertilization
ex. herring, carp, tuna
cud
chewed vegetation that gets regurgitated from the 1st stomach chambers then gets chewed again (mechanical breakdown of food)
crop
an organ of many invertebrates that stores food until it is processed for absorption
cardiac muscle
cells with branched endings that interlock with each other, keeping muscle fibers from ripping apart during contractions
visceral sensory nerves
carry impulses from the body organs to the CNS
somatic sensory organs
carry impulses from the body surface to the CNS
sympathetic nervous system
carry impulses that stimulate organs (as opposed to the parasympathetic nervous system, which carries impulses back from organs)
forebrain
the most anterior part, contains olfactory bulbs (sense of smell), cerebrum (sensory/motor response, memory, speech, intelligence)
thalamus: integrates senses
hypothalamus: hunger, thirst, BP, temp
pituitary gland: hormone release
midbrain:
contains optic lobes (connected via optic nerves)
hindbrain
consists of cerebellum and medulla oblongata
bile
produced in the liver. aids in digesting fats; carries away broken down pigments and chemicals (from pollutants/medication), then secretes them into the small intestine
spermatogenesis
diploid primary spermatocytes undergo meiosis I and form haploid secondary spermatocytes with single chromosome set. then go thru meiosis II and form haploid spermatids which develop into sperm cells
oogenesis
primary oocytes in ovaries undergo meiosis I, form 1 secondary oocyte and 1 smaller polar body. both undergo meiosis II - the oocyte produces 1 haploid egg cells and another polar body (3 now)
embryonic development
morula (cluster of cells) –> blastula (thin mayer of cells surrounding internal cavity) –> gastrula (2 layered cup shape) which becomes double layered tube
germ layers
ectoderm: skin, endocrine glands, nervous system
endoderm: gut lining/accessory structures
mesoderm: muscles; organs of skeletal, circulatory, respiratory, reproductive, excretory
chorion
extraembryonic membrane #1. lies in contact with innermost surface of shell in egg laying vertebrates - in other vertebrates, is the outermost membrane surrounding embryo in contact with the uterus
regulates passage of H2O/gases from embryo to environment. in embryos without shells, also to move nutrients and waste
amnion
within the chorion. filled with amniotic fluid which cushions the embryo, keeps temps constant. fluid keeps amniotic membrane from sticking to developing embryo
allantios
the 3rd membrane that arises from developing digestive tract - becomes part of umbilical cord in humans - contains BVs for gas/nutrient exchange between fetus and mother
in egg laying reptiles, is waste reservoir. fuses with chorion to form chorioallantoic membrane that regulates gas exchange
yolk sac membrane
encloses yolk sac that forms developing digestive tract and becomes part of umbilical cord. stores nutrients for embryo to use. gives rise to gametes
parthenogenesis
type of asexual reproduction that doesn’t require fertilization by males to form an embryo/develop
ex. fish, sharks, reptiles
“=spheres”
biosphere - all living things of earth
atmosphere - air
lithosphere - ground
hydrosphere - water
ecosystem
a group of populations within a given locality plus the inanimate environment
population
the total number of a single species of organism in a given ecosystem
community
populations that interact with each other in a particular ecosystem
hydrologic cycle
- water evaporates from bodies of water into clouds via solar radiation (also released from vegetation via transpiration)
- water underground flows into aquafiers - empty into oceans
- water is redistributed over land via clouds (precipitation)
greenhouse gas
reflects radiation from Earth’s surface back towards the earth and traps it as heat
nitrogen fixing
makes N available for absorption by roots. the process of combining gaseous N2 with H or O to form a non-gas compound to be used directly by plants
these bacteria live in soil, make NH4+
nitrification
process that further breaks down NH3 into nitrites NO2- and nitrates NO3-
ammonification
large amounts of N are returned to the Earth by bacteria and fungi, which decompose dead plant and animal matter into ammonia
denitrification
bacteria and fungi break down excess nitrates to release N2 gas back into the air
fossil fuels
when burned for energy, the combustion process releases CO2 back into the atmosphere where plants use it for photosynthesis
natality
birth rate
mortality
death rate
2 models of population growth
exponential curve: J curve - no environmental/social limit to population size, only occurs during initial growth
logistic curve: S curve - limiting factors
limiting factors
the biotic and abiotic factors that determine how much a particular population within a community will be able to grow
density independent factors
abiotic limiting factors
range
the total area occupied by a species
dispersion
species may move in or out of a particular area
emigration, immigration, or migration
ammensalism
a type of symbiosis where 1 species is neither helped nor harmed while it inhibits the growth of another species
closed community
one whose populations occupy essentially the same range with very similar distributions of density
ecotones
boundaries of closed communities (ex. pond aquatic ecosystem ends at the shore)
open community
has infinite boundaries, populations have varying ranges and densities (ex. forest), species are more widely distributed, animals may travel in and out of an area
succession
when 1 community completely replaces another over time in a given area - occurs in terrestrial and aquatic biomes
pioneer communities
the first populations that move back into a disturbed ecosystem - tend to be hardy species that can survive in bleak conditions
climax community
when succession ends in a stable community
biogeography
the study of how photosynthetic organisms and animals are distributed in a particular location plus the history of their distribution in the past
ethology
how animals act and react within their environments - “behavior”
innate behaviors
the actions of animals that are instincts, are highly stereotyped - all individuals of a species perform these behaviors in the same way
- taxes
- kineses
- reflexes
- fixed action patterns (FAP)
taxes
directional responses towards/away from a stimulus
kineses
changes in speed of movement in response to a stimuli
reflexes
automatic movement of a body part in response to a stimulus
fixed action patterns (FAP)
complex, but stereotyped response to a stimulus. not learned
a pre-programmed response to a releaser/sign stimulus
ex. courtship behaviors, circadian rhythms, feeding of young
habituation
learned behavior where an organism produces less and less response as a stimulus is repeated
imprinting
a learned behavior that develops in a critical or sensitive period of the animals lifespan
generally involves learning a new releaser for an established FAP
society
an organization of individuals of a population in which tasks are divided in order for the group to work together
cotyledon
where food is stored in a seed
2=dicots - oaks/flowers/vegetables. branched/networked veins vascular bundles in rings taproots with smaller secondary roots petals in 4s or 5s
1=monocots - grass, lillies, palm trees parallel veins random vascular bundles fibrous roots petals in 3's
nodes
the locations along the stem where leaves sprout (internode is in between)
lateral buds
what new leaves begin as
xylem
long, tubular cells which transport water up from the ground to the branches and leaves
phloem
stacked cells connected by sieve plates which allow nutrients to pass from cell to cell, transports food made by leaves to the rest of the plant
palisade layer
uppermost layer that contains vertically aligned cells with numerous chloroplasts. maximizes exposure to sunlight - where photosynthesis occurs
spongy layer
below palisade layer - a layer of parenchyma cells separated by large air spaces which allow for gas exchange (CO2 and O2) for photosynthesis
regions of roots
maturation region: differentiate into various root tissues
elongation region: cells differentiate, vacuoles grow, cells grow
meristematic region: undifferentiated cells that carry out mitosis
root cap: dead, thick walled cells that protect the root as it pushes through soil
parenchyma
constitutes cortex (beneath epidermis) thin walled cells loosely packed, allow for flow of gases and mineral uptake
endodermis
a ring inside the cortex - single layer of cells tightly connected - nothing can pass thru. allows it to act as a filter
vascular cylinder
in the center of the root, includes xylem and phloem
C3 plants
over 95% of all plants use rubisco to make 3C compound during carbon fixation. cool, damp, cloudy climates
C4 plants
(grasses, sugar caine, maize) very low rate of carbon loss thru photorespiration. hot and dry environments, efficient water use
sporophyte
diploid (2n) generation - produce gametophytes via meiosis (haploid)
vegetative propagation
asexual reproduction - occurs only through mitosis (no gametes) - offspring genetically identical to parents
reproductive structures of plants
tubers: underground storage stems which develop new shoots
rhizomes: underground runners, become new plant
stolens: above ground runners, grow roots of their own then become new plant
bulbs: underground storage, grow into new plants via division
corms: resemble bulbs with enlarged solid stem for food storage
plant hormones
giberellins: cell division/elongation
cytokinins: cell division, fruit development
abscisic acid: open/close stomata
ethylene: fruit ripening, metabolic activity
auxins: growth factors
tropism
involuntary response of an organism to external stimuli (light, water, gravity, nutrients)
egestion
the elimination of indigestible materials
alimentary canal
the GI tract: mouth, pharynx, esophagus, stomach, SI, LI, rectum, anus
accessory organs: teeth, tongue, salivary glands liver, gallbladder, pancreas
ruminants
vertebrates (cow and deer) that consume large amounts of vegetation
