Biology Flashcards
Cell Theory
1) All living things are composed of cells
2) Cell is the functional unit of life
3) Cells arise from only cells
4) Cells carry genetic info via DNA which is passed from parent to daughter cells.
Are viruses considered living things?
No, because they are Acellular, use RNA to carry info, and cannot reproduce on their own
Eukaryotic Cells
Cells with membrane-bound organelles, nucleus, can form multicellular organisms
Nucleolus
The subsection of the nucleus that synthesizes rRNA
Lysosomes
Cell containing hydrolytic enzymes to break down substances.
Endoplasmic Reticulum
Organelle which is continuous with the nuclear envelope. Rough ER has ribosome for protein secretion smooth ER is involved in lipid synthesis.
Golgi Apparatus
The organelle that modifies, packages, and directs cellular products to specific cellular locations
Peroxisomes
Organelle containing hydrogen peroxide which can break down fatty acid chains via beta oxidation. Participate in phospholipid synthesis and pentose phosphate pathway.
Microfilaments
composed of actin provides structural protection and can cause muscle contraction via interactions with myosin. They help form the cleavage furrow during cytokinesis
Microtubules
Composed of tubulin, they create pathways for motor protons to move along, They contribute to the structure of cilia and flagella, where they are organized into 9+2 ring structure.
Kinesin
Motor Protein antereograde
Dynein
Motor Protein retrograde
Centrioles
found in centrosomes they are involved in microtubule organization into mitotic spindles
intermediate filaments
involved in cell/cell adhesion and maintenance of cytoskeletons. They anchor organelles and include keratin and desmin
Parenchyma
function parts of the organ often formed by epithelial cells
epithelial cells
lining cells, they protect from the outside environment, some can absorb or secrete substances, some participate in sensation. They can be classified by layers (simple, stratified, pseudostratified), or by shape (cuboidal, columnar, squamous)
connective tissue
Form the stroma or support structures, secrete substances to form extracellular matrix, consist of bone, cartilage, tendons, adipose, and blood for examples
Prokaryotes
cells with no membrane-bound organelles, genetic material stored in single loop of DNA called nucleoid region. Include bacteria and archaea
Archaea
extremophiles, can use chemical sources of energy, have similarities to both eukarotes and prokaryotes
Domains of life
Archaea, Bacteria, Eukarya
Bacteria shape classifications
Cocci (sphere) Bacilli (rod) Spirilli (spiral shaped)
Obligate aerobes
need oxygen for metabolism
Obligate anaerobes
Cannot survive in an oxygen environment and can only carry out anaerobic metabolism
Faculative anaerobes
Survive in environments regardless of oxygen presence, will toggle between metabolic processes based on the environment
Aerotolerant anaerobes
Can’t use oxygen for metabolism but can survive in an oxygen-containing environment.
Gram positive bacteria
When stained turn purple, they have thick cell walls composed of peptidoglycan and lipoteichoic acid
Gram Negative Bacteria
When stained turn pink-red, they have thin walls made of peptidoglycan and an outer membrane with phospholipids and lipopolysaccharides.
Chemotaxis
movement in response to chemical stimuli
ETC in prokaryotes
occurs in the cell membrane
Prokaryotic ribosomes vs Eukaryotic ribosomes
30S/50S vs 40S/60S
Binary fission
how prokaryotes multiply, chromosome replication occurs while cell grows in size until the cell wall grows inward along midline to divide cell into two
episomes
plasmids that can integrate into the genome
transformation
hen genetic material is taken up by a cell from its surroundings
Conjugation
transfer of genetic material between bacteria via conjugation bridges. Plasmids can be transferred from F+ to F- cells or a portion of the genome can be transferred from an Hfr cell to a recipient
transduction
transfer of genetic material via bacteriophage
transposons
genetic elements that can insert into or remove themselves from the genome
bacterial growth pattern
lag phase, exponential log phase, stationary phase, death phase
Capsid
viral protein coat
positive sense RNA virus
can be translated by host cell
negative sense RNA virus
complimentary strand must be synthesized and translated by host cell
retroviruses
contain single strand RNA from which DNA is made via reverse transcriptase. This DNA is then integrated into the genome
Lytic cycle
bacteriophase produces virons until cell lyses
Lysogenic Cycle
virus integrates into host genome and reproduces along with the cell. Can stay indefinitely or enter lytic cycle.
Prions
infectious misfolded proteins which trigger further misfolding of other proteins
Viroids
Small circles of complementary RNA that acts as plant pathogens
Diploid
2n
Haploid
n
Cell Stages
(G1, S, G2, M, G0) All but M can be called interphase
G1
Presynthetic gap, cells create organelles, proteins, and increase their size, restriction point occurs to check DNA for quality. This must be passed to proceed to S
S
DNA is replicated
G2
Further cell growth and replication of organelles in preperation for mitosis. ANother quality checkpoint occurs to go into mitosis
M
Mitosis and cytokinesis occurs
G0
cell performs its functions without preparing for division
p53
functions in the two check points from G1 to S and G2 to M
Mitosis Phases
Prophase, metaphase, anaphase, telophase, cytokinesis
Prophase
Chromosomes condense, nuclear membrane dissolves, nucleoli dissapears, centrioles migrate to cell ends, spindle apparatus begins to form, kinetichores of each chromsome are contacted by spindle fibers
metaphase
chromosomes align on the metaphase plate
anaphase
sister chromatids separate
telophase
nuclear membrane reforms, spindle apparatus disappears, cytosol and organelles then split into two daughter cells via cytokinesis
Meiosis I
homologous chromosomes are separated from each other
Prophase I
Same events as mitosis prophase but homologous chromosomes intertwine (synapsis) and form tetrads. Crossing over occurs and accounts for Mendels second law (independent assortment)
Metaphase I
Homologous chromosomes line up on opposite sides of the metaphase plate
Anaphase I
homologous chromsomes are pulled to opposite poles of the cell accounting for Mendel’s first law (segregation)
Telophase I
Chromosomes decondense and cell enters interkenisis after cytokinesis
Meiosis II
Sister chromatids seperate in a process similar to mitosis
Seminiferous tubules
Where sperm is produced in the testes
Sertoli Cells
Nourish Sperm
Leydig Cells
secrete testosterone and androgens
epididymis
where sperm gains motility and is stored
seminal vesicles
nourish sperm with fructose and produce alkaline fluid
prostate
produces alkaline fluid
bulbourethral glands
produce clear fluid that cleans out any remnants of urine and lubricates urethra during arousal
Spermatogenesis
four haploid sperm are formed from a spermatogonium
Sperm stages
After S stage primary spermatocyte, after meiosis I secondary spermatocyte, after meiosis II spermatids, after maturity spermatozoa
follicles
where ova (eggs) are formed
Oogenesis
one haploid ovum and a variable number of polar bodies are formed from an oogonium
Ova stages
at birth oogonia have undergone replication and are arrested in prophase I, ovulated eggs are secondary oocytes arrested in metaphase II, when fertilize it will complete meiosis II to become a true ovum
Zona pellucida
glycoproteins that protect oocyte and help sperm binding
Corona Radiata
the layer of cells that adhere oocyte during ovulation
Menstral Cycle Phases
Follicular phase, ovulation, lucteal phase, and menstruation
Follicular phase
GnRH secretion stimulates FSH and LH which promotes follicle development. Estrogen is released stimulating vascularization and glandularization of the decidua
Ovulation
Stimulated by a surge in LH which is triggered by estrogen levels reaching a threshold and switching from negative to positive feedback effects. Results in an egg being released
Luteal Phase
LH causes the ruptured follicle to become the corpus luteum which secretes progesterone that maintains the uterine lining. High estrogen and progesterone levels cause negative feedback on GnRH LH and FSH
Menstruation
occurs when there is no fertilization. As estrogen and progesterone levels decline the endometrial lining sloughs off and the block on GnRN is removed.
Menopause
Menstruation stops and FSH and LH levels rise
Where does fertilization occur
The ampulla of the fallopian tube
Acrosomal apparatus
Sperm establishes this to inject its pronucleus into the egg
Cortical Reaction
Term for the increase metabolic rate after fertilization
Indeterminate cleavage
results in cells capable of becoming any organism
determinate cleavage
results in cells commited to differentiation
Stages of embryotic brydevelopment
Egg, morula, blastula, 2 layered gastrula, 3 layered gastrula
Chorion
Contain chorionic villi which penetrate the endometrium and create the interface between maternal and fetal blood
Before the placenta is established what nourishes the embryo
yolk sac
amnion
produces amniotic fluid
gastrulation
process during embryonic development that changes the embryo from a blastula with a single layer of cells to a gastrula containing multiple layers of cells. Gastrulation typically involves the blastula folding in upon itself or dividing, which creates two layers of cells
ectoderm becomes
becomes epidermis, hair nail, epithelial cells, anal canal, and the nervous system and lens of the eye
mesoderm becomes
musculoskeletal system, circulatory, excretory, gonads, connective tissue,
endoderm
epithelial linings of respiratory and digestive system and parts of the pancrease, thyroid, bladder, and distal urinary tract
Neurulation
development of therse nervous system it begins after the formation of the three germ layers
Neural Crest Cells
become the peripheral nervous system
teratogens
substances that interfere with embryonic and fetal development causing defects or even death
morphogens
promote cell develpment down a specific line
cell competency
the ability of a cell to be influenced by morphogens
Differentiation
changes to a cell due to selective transcription
totipotent cells
can differentiate into all cell types including placental structures
pluripotent cells
differentiate into the three germ layers and their derivatives
multipotent cells
can differentiate into specific subsets of cells
reciprocal induction
when two tissues induce further differentiation in each other
apoptosis
programmed cell death
senescence
essentially aging, related to shortening of telomeres
Fetal Hemoglobin
higher oxygen affinity that adult heoglobin
umbelical arteries
carry deoxygenated blood from fetus to placenta
umbelical veins
carry oxygenated blood from placenta to fetus
foramen ovale
connects right atrium to left atrium to bypass lungs
ductus arteriosus
connects pulmonary artery to aorta bypassing lungs
ductus venosus
connects umbelical vein to inferior vena cava bypassing the liver
Dendrites
recieve impulses
soma
cell body
axon hillock
where axon begins and action potentials are initiated
axon
long appendage down action potentials move
synaptic bouton or terminal
where neurotransmitters are relased into cleft
Nodes of Ranvier
exposed areas of mylenated axons that permit saltatory conduction
oligodendrocytes
mylenate the central nervous system
schwann cells
mylenate the peripheral nervous system
nerves / tracks
bundles of axons
ganglia
clusters of cell bodies of neurons of the same type in the peripheral nervous system
Nuclei
clusters of cell bodies of neurons of the same type in the central nervous system
Resting membrane potential
-70mV, maintained by sodium-potassium ATPase pumps
Astrocytes
nourish neurons, form BBB,
Ependymal cells
line ventricles and produce Cerebrospinal Fluid
Microglia
phagocytic cells in the CNS
Sodium Potassium Pumps
pump three sodium out for two potassium in
action potential
occurs when cell is depolarized to threshold voltage. Sodium channels open until causing influx up to peak where they are inactivated then potassium channels open. Potassium flows out repolarizing cells and stays open until hyperpolarization ocurrs. Then sodium-potassium pumps bring back to resting membrane potential.
Absolute refractory period
another action potential cannot occur
Relative refractory period
cell is hyperpolarized, a stronger than usual stimuli can cause an action potential
How AP causes Neurotransmitter release
AP opens voltage gated Calcium channels whose influx causes fusion of vesicles filled with NT with the cleft leading to their release
Peptide Hormones
made of amino acids, polar and cannot pass through membranes, bind to extracellular receptors to trigger signaling cascade. Hormones are water soluble, and can freely travel in the blood stream.
Steroid Hormones
Polar and can pass through membranes, binds to intracellular receptors, or binds to DNA to alter transcription. Must be carried by specific proteins.
Amino Acid Derivative Hormones
Share features of both peptide and steroid hormones.
Direct Hormones
Have major effects on non endocrine tissues
Tropic Hormones
Have major effects on other endocrine tissues
Gonadotropin releasing hormone GnRH
Promotes the release of FSH and LH
Growth Hormone Releasing Hormone GHRH
Promotes the release of growth hormone
TRH
Promotes the release of TSH
Follicle Stimulating Hormone FSH
Promotes development of ovarian follicles in females and spermatogenesis in males
Luteinizing Hormone LH
Promotes ovulation in females and testoerone production in males
Adrenocorticotropic hormones
Promotes synthesis and release of glucocorticoids from adrenal cortex
Thyroid Stimulating Hormone
Promotes synthesis and release of T3 and T4
Prolactin
Promotes milk production
Endorphins
decrease perception of pain
Growth Hormone GH
promotes growth of bone and muscle and shunts glucose to these tissues. Increases blood glucose.
Antidiuretic hormone ADH also called vasopressin
Secreted in response to low blood volume and increased blood osmolarity and increases reabsorption of water in the collecting ducts of nephrons to increase blood volume
Oxytocin
promotes uterine contraction, milk ejection, and is involved in maternal bonding. Unusual as it has a positive feedback loop.
Where are T3 and T4 produced
Follicular Cells of the thyroid
Calcitonin
Produced by parafollicular cells it decreases plasma calcium concentrations by promoting excretion and decreasing absorption in the gut and promoting storage in bones
Parathyroid hormone
produced by the parathyroid glands. Increases blood calcium by decreasing excretion, activating vitamin D to increase absorption, promotes resorption of phosphate from bone and reduces the reabsorption of phosphate in kidney. Vitamin D promotes absoprtion of phosphate from gut so they cancel each other out
glucocorticoids
cortisol and cortisone they increase blood glucose, reduce protein synthesis, inhibit immune system, and are stimulated by ACTH
Mineralocorticoids
Examples include aldosterone, they promote sodium reabsorption in the distal convoluted tubule and colecting duct to also increase water reabsorption. Aldosterone is regulated by the renin angiotensin pathway
Where are catecholamines released
adrenal medulla releases them including epinephrine and norepinephrine
Alpha cells
produce glucagon which raises blood glucose by stimulating protein and fat degradation, glycogenolysis, and gluconeogensis.
beta cells
produce insulin which lowers blood glucose levels, stimulates glucose uptake by cells, and promotes glycogen fat and protein synthesis.
lambda cells
produce somatostatin
somatostatin
inhibits insulin and glucagon secretion
Intestinal and Gastric Hormones
secretin, gastrin, and cholecystokinin
Atrial natriuretic peptide
promotes excretion of salt and water in kidneys in response to stretching of the atria from high water volume in the blood
thymosin
secreted by the thymus for proper t cell development
Pathway of air in respiration
nares, pharynx, larynx, trachea, bronchi, bronchioles, alveoli
surfactant
reduce surface tension at the liquid-gas interphase of alveoli to prevent it from collapsing
visceral pleura
lies adjacent to the lung
parietal pleura
lines the chest wall
intrapleural space
between visceral and parietal pleura
diaphragm
thin skeletal muscle that created pressure differential for breathing
muscles involved in breathing
diaphragm and the intercostal muscles
negative pressure breathing
pressure differential expands lungs by dropping the preassure within and draing lung from environment. This is achieved by diaphragm contracting.
Total Lung Capacity
Maximum volume of air remaining in the lungs
Residual volume
volume of air remaining after fully exhaling
vital capacity
difference between total lung capaciy and residual volume basically difference between the minimum and maximum amounts of air in the lungs
tidal volume
air volume moved in a normal breath
expiratory reserve volume
volume of additional air that can be forcibly exhaled after a normal exhalation
inspiratory reserve volumes
volume of additional air that can be forcibly inhale after a normal exhalation
ventilation is regulated by what brain structure
medulla oblongata
Pathway of blood from right atria
right atria, tricuspid valve, right ventricle, pulmonary valve, pulmonary artery, lungs, pulmonary veins, left atrium, mitral valve, left ventricle, aortic valve, aorta, arteries, arterioles, capillaries, venules, veins, venae cavae, right atrium
electric conduction in the heart
SA, AV, bundle of His, purkinje fibers
Systole
ventricular contraction where AV valve is closed
Diastole
heart is relaxed
cardiac output
heart rate X stroke volume
portal system
when blood passes through two capillary beds in series
hepatic portal system
blood travels from gut beds to liver beds
hypophyseal portal system
blood travels from hypothalamus beds to anterior pituitary beds.
renal portal system
glomerulus to vasa recta through efferent arterioles
Aspects that cause a right shift in the oxyhemoglobin dissociation curve. What does this mean?
High CO2, High H+, Low pH, high temperature, high 2,3BPG, cause a right shift this means that there is a decreased affinity for oxygen
Innate Immunity
Defenses that are always active but do not target specific invaders and do not maintain memory. Also called non specific immunity
Adaptive Immunity
Defenses that take time to activate but are specific and maintain memory they are also called specific immunity
Where are immune cells made
bone marrow
Where are immune responses mounted and B cells activated
Spleen and lymph nodes
Where is the site of T cell maturation
Thymus
Leukocytes
White blood cells
Defensin
antimicrobial compound secreted the skin
Complement system
punches holes in the cell walls of bacteria making them osmotically unstable
interferons
given off by virally infected cells they help prevent viral replication and dispersion to nearby cells
Macrophages
ingest pathogens and present them on major histocompatibility complex molecules (MHC)
MHC class I
Present in all nucleated cells and display endogenous antigens to cytotoxic T-cells (CD8+)
MHC Class II
Present in some antigen-presenting cells display exogenous antigens to helper T-cells (CD4+)
Dendritic cells
antigen presenting cells in the skin
Natural killer cells
they attack cells not presenting MHC molecules which would include virally infected cells and cancer cells
Granulocytes
include neutrophils, eosinophils, and basophils
Neutrophils
ingest bacteria, specifically opsonized bacteria (bacteria marked by antibodies) they follow the bacteria via chemotaxis
Eosinophils
they release histamine in response to allergic reactions and invasive parasitic infections
Basophils
used in allergic reactions Mast cells are similar cells found in the skin
Humoral Immunity
Centered on antibody production by plasma cells which are activated by B-cells
Memory B cells
lie in wait for second exposure to a pathogen and cal mount a more rapid and vigorous response (secondary response)
Cell mediated immunity is centered around white type of cell
T cells
Helper T Cells CD4+
Respond to antigens on MHCII by secreting lymphokines to activate immune difenses.
Interferon gamma
activates macrophages and secreted by helper T cells 1
Helper T cells II
activate B cells
Cytotoxic T Cells CD8+
responds to antigens on MHC-1 and kill virally infected cells
Supressor T Cells Treg
Tone down immune response after infection
Memory T Cell
serve similar function to memory B cell
Active immunity
Activation of B cells to produce antibodies
Passive Immnity
transfer of antibodies to an individual
Thoracic duct
connect lymphatic and circulatory system
purpose of the lymphatic system
equalizes fluid distribution, transports fats and chylomicrons, provides sites for mounting immune responses
Accessory organs of digestion
salivary glands, pancreas, liver, and gallbladder
enteric nervous system
wall of alimentary canal and controls peristalsis. Regulated by the sympathetic and parasympathetic nervous system
Hormones that support thirst
antidiuretic hormone, aldosterone
Hormones that support hunger
glucagon, ghrelin
Hormones that support satiety
leptin and cholecytokinin
stomach mucous cells
synthesize bicarbonate buffer
Chief cells
secrete pepsinogen, which when activated by stomach acid (HCl) becomes pepsin which works to break down proteins.
Parietal Cells
secrete HCl and intrinsic factor which is needed for vitamin B12 absorption
G-Cell
secretes gastrin which increases HCl secretion as gastric motility
Dissachardases
break down dissarchide into monosaccharaides hey are brush border enzymes
Enteropeptidase
activates trypsinogen and procarboxypeptidase initiating an activation cascade
Secretin
stimulates the release of pancreatic juices into the digestive track and slows motility
Cholecystokinin
stimulates bile release, and pancreatic juices, and deals with satiety
Acinar Cells
Located in the pancreas and produce bicarbonate, pancreatic amylase, pancreatic peptidases (trypsinogen, chymotrypsinogen, carboxypeptidase A and B), and pancreatic lipase
Jejunum and Ileum function
major in absorption via villi and microvilli which contain lacteals and capillary beds
Nephron segments in order
PCT, descending limb of the loop of Henle, ascending lib of the loop of Henle, DCT, collecting duct
PCT
site of bulk reabsorption of glucose, amino acids, soluble vitamins, salt, and water. Site of secretion of H+, K+, ammonia, and urea
descending limb of the loop of Henle
Permeable to water, not salt so water is reabsorbed as it moves down into the more concentrated renal medulla.
Countercurrent multiplier system
Vasa recta and nephron flow in opposite directions allowing maximal reabsorption of water
Ascending limb of the loop of Henle
Permeable to salt but not water so salt is reabsorbed.
DCT
responsive to aldosterone and is the site of salt reabsoption and waste product excreption
Collecting duct
responsive to aldosterone and antidiuretoc hormone and has variable permeability depending on the bodies need.
aldosterone
steroid hormone regulated by renin, angiotensin, aldosterone, system that increases sodium reabsorption and thus water reabsorption
Antidiuretic hormone
peptide hormone synthesized by hypothalamus and released by the posterior pituitary in response to low blood volume or high blood osmolarity. It increases permeability of collecting duct to increase water reabsorption
epidermis Layers
Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum.
Melanocytes
make melanin
Langerhans Cell
macrophages in skin. serve antigen presenting cells
dermins layers
papillary layer, reticular layer
merkels cells
deep pressure and texture
free nerve endings
pain
meissners corpuscles
light touch
ruffini endings
stretch
pacinian corpuscles
deep pressure and vibration
Skeletal muscle
voluntary, striated, polynucleated
red twitch fibers
carry out oxidative phosphorylation
white twitch fibers
use anaerobic metabolism
Smooth Muscle
In respiratory, reproductive, cardiovascular, and digestive systems. Nonstriated, involuntary, and uinucleated.
myogenic activity
can contract without neural imput found in smooth and cardiac muscle
cardiac muscle
striated, involuntary, uninucleated/binucleated, myogenic. Connected with intercalated discs that contain gap junctions
sarcomere
funcitonal unit of muscle consisting of myosin and actin. Troponin and tropomyosin are found on actin and regulate interactions between the filaments.
Z line
end boundaries of sarcomere
M line
middle of sarcomere
I band
contains only thin filament actin
H zone
contains on thick filament myosin
A band
The thick filament in its entirety it is the only part of the sarcomere that maintains a constant length
T tubules
connect to sarcolemma and allow action potential to reach all parts of the muscle
what causes the sarcolemma to depolarize
acetylcholine from nerves
How does calcium cause power strokes
calcium binds to troponin which shifts tropomyosin, and exposes myosin binding sites on the actin
tetanus
prolonged and stronger contraction from frequency summation of twitches
creatine phosphate
makes ATP in muscles
myoglobin
oxygen reserve in muscles
compact bone
provides strength. Dense
spongy bone
filled with bone marrow
Long bones
shaft is called diaphyses which flare to form metaphyses and terminate in epiphyses. Epiphysis contains epiphyseal growth plate
periosteum
connective tissue surrounding bones
tendons
attach bones to muscles
ligaments
attach bones to bones
how are bones organized internally
into rings called lamellae around central canal. Unit is called osteon
lacunae
between lamellar rings where osteocytes reside. Connected to canaliculi to allow nutrient and waste transfer
osteoblasts
build bone
osteoclasts
break down bone
Parathyroid hormone bone consequence
increases resorption of bone increasing blood calcium and phosphate
vitamin D
increases resorption of bone increasing blood calcium and phosphate
Calcitonin
increases bone formation
chondrocytes
secrete chondrin to make cartilage
endochondral ossification
how bones are formed from cartilage in fetal life
immovable joints
fused together to make sutures
movable joints
contain synovial capsule
articular cartilage
coating of bones in joints to aid movement
antagonistic pairs
muscles that serve in opposite functions so that when one contracts the other relaxes.
hemizygous
having only one allele like the male sex chromosome
complete dominance
effects of one allele completely mask the effects of others
codominance
more than one dominant allele
incomplete dominance
no dominant alleles have an intermediate phenotype when heterozygous
penetrance
the proportion of the population with a given genotype who express the phenotype
expressivity
the varying phenotypic manifestation of a given genotype
Mendels first law
law of segregation. Organisms have two alleles for each gene which segregate during meiosis resulting in gametes carrying one gene.
Mendels second law
independent assortment. States that inheritance of one allele does not influence the probability of inheriting an allele for a different trait.
point mutation
substitution of singular nucleotide for another
frameshift mutation
moving the three letter transcriptional reading frame
silent mutation
has no effect
missense mutation
results in substitution of one amino acid for another
nonsense mutation
early stop codon
deletion mutations
large segment of DNA is lost
duplication mutation
segment of DNA is copied multiple times
inversion mutation
segment of DNA is reversed
insertion mutation
segment of DNA is moved from one chromosome to another
translocation mutation
segment of DNA is swapped with a segment of DNA from another chromosone
Genetic leakage
flow of genes between species through hybrid offspring
genetic drift
when composition of gene pool changes as a result of chance
founder effect
results from bottle necks that suddenly isolate small population leading to inbreeding and increased prevalence of certain homozygous genotypes
recombinant frequency
likelihood of two alleles being separated during crossing over
punctuated equilibrium
evolution slow process with intermittent bursts of change
Stabilizing selection
excludes extremes
directional selection
moves to one extreme
disruptive selection
moves to two extremes. Can lead to speciation
adaptive radiation
rapid emergence of multiple species from common ancestor each of which occupies its own niche
divergent evolution
two species sharing common ancestor become more different
parallel evolution
two species sharing common ancestor evolve in similar ways
convergent evolution
two species not sharing common ancestor evolve in similar ways
