Term
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Definition
| determining the components, or building blocks |
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Definition
| determines how the components work together |
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Term
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Definition
relationships developing within components.
examples: negative feedback, positive feedback |
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Term
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Definition
| the concentration of the end product inhibits an enzyme earlier in the pathway. prevents more production, maintaining homeostasis and optimal level of functioning |
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Term
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Definition
| concentration of the end product increases the activity of synthesis- creates more product. this mechanism is very unstable because it leads to problems with controlling the cascade |
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Term
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Definition
| shows proteins and interactions(by lines connecting) with other proteins. Allows researchers to predict how one change can begin a cascade of events altering other molecular circuitry |
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Term
| feedback example- ovarian cycle |
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Definition
pituitary secretes hormone acting on ovaries-> creates estradiol which causes negative feedback to the pituitary. Prior to ovulation, estradiol has a positive feedback to pituitary making MORE estradiol up to the point of ovulation. At ovulation the mechanism reverses back to negative feedback.
Unknown what changes at the feedback switch |
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Term
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Definition
| seeks to understand a phenomenon or behavior by comparing two closely related species (or individuals) that vary by ONLY the phenomenon in question |
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Term
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Definition
a lot of similarity of structure and function across diversity- especially cellularly and molecularly.
--->allows comparative biology to work
example: cross section of paramecium cilia and the cilia of human windpipe cells are IDENTICAL |
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Term
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Definition
| said that for every biological problem, there is an organism that has 'figured' it out |
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Term
| Jerison's Principle of proper mass |
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Definition
| the mass of specific neural tissue is proportional to the amount of information processing needed to perform the function |
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Term
| testing Jerison's principle of proper mass |
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Definition
pine vole- males and females have no difference in foraging range, are monagamous
meadow vole- males have a much farther spatial range, are polygamous
no other significant differences
RESULTS:
pine vole- same size hippocampus
meadow vole- male hippocampus is larger |
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Term
| models for animal(vertebrate) development |
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Definition
sea urchin eggs- large, transparent, easy to maintain
frog(xenopus)- vertebrate, eggs large and easy to manipulate.
will transcribe injected RNA's
Chicken(gallus)- amniotic egg(closer to mammals), everything necessary for development contained in egg
zebra fish- transparent eggs, 20 days to full development |
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Term
| fertilization- acrosomal reaction |
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Definition
1- contact btw sperm and egg triggers exocytosis from acrosome
2- released enzymes digest jelly layer, actin forms acrosomal process, binds to receptors on egg membrane (protrude through vitelline envelope)
3- vitelline layer is penetrated, membranes fuse. depolarization of membrane is fast block to polyspermy(via G protein, second messenger, release of Ca2+)
4- sperm nucleus enters
5- cortical discharge contents outside egg, perivitteline space swells, digests sperm receptors, creates fertilization envelope-(vitelline layer(zona pellucida in mammals-hardens(impervious) |
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Term
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Definition
no growth stages- splits cytoplasm(holoblastic division=complete division)
zygote-> 4 cell stage-> Morula(beginnings of blastocoel, still enclosed in fertilization envelope)-> Blastula(large blastocoel, still in envelope, single layer of cells) |
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Term
| cleavage in eggs with yolk |
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Definition
cleavage creates blastomeres larger at vegetal pole(where yolk is), smaller at animal pole.
blastocoel does not occupy center of blastula(is in animal pole hemisphere)
first two divisions meridional(pole to pole), 3rd is equatorial |
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Term
| chicken egg development(with yolk) |
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Definition
| early cell divisions are meroblastic(incomplete), blastocoel rests on undivided yolk. |
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Term
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Definition
| invagination(blastopore, archenteron) occurs at vegetal pole when mesenchyme cells migrate into blastocoel, mesenchyme cells at tip of archenteron tube make filopodia to pull outer cells in and tube across the blastocoel, fusion creates digestive tube, endoderm, mesoderm, and ectoderm |
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Term
| amniotic egg and membranes |
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Definition
encapsulates aqueous environment within egg
Amnion- protects embryo in fluid environment(against dehydration and physical shock)
Allantois- disposal sac, can function in respiratory
Chorion- respiratory, exchanges gases with surrounding air
Yolk Sac- holds yolk, blood vessels bring nutrients to embryo |
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Term
| gastrulation in eggs with yolk(chick embryo) |
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Definition
| invagination of epiblast gives the primitive streak--> 3 germ layers |
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Term
| fate mapping and cell lineage analysis |
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Definition
fate mapping- mark regions of a blastula or gastrula. section embryos later in development to see what those areas gave rise to.
cell lineage analysis- inject dye into only one cell. Later in development, cells with that dye must have come from that one cell |
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Term
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Definition
cytoplasmic determinants influence blastomere fate.
grey crescent split in two at first cleavage.
(to develop complete embryo, need animal pole, vegetal pole, and grey crescent) |
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Term
| where does the head come from? |
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Definition
transplant dorsal lip of one newt gastrula to 180º from 2nd newt dorsal lip
Result 1- secondary embryo inside primary
Result 2- secondary embryo belly to belly with primary
both results- donor tissue developed into notochord of secondary embryo, all other tissues from host embryo
MEANING- cells in the dorsal lip induce cells to form secondary embryo. Because both embryo heads were facing same direction, axis must be established before transplant in host cell |
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Term
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Definition
ectoderm thickens-> becoming neural plate-> which folds and fuses to form the neural tube.
the basal plate(ventral/anterior) becomes the motor portion of nervous system- nerve cells in muscle tissue
the alar plate(dorsal/posterior) becomes sensory portion |
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Term
autocrine signaling
(specificity, range) |
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Definition
cell makes protein in ER, binds to receptors within own cytoplasm
intracrine- secretes outside, has membrane surface receptors
autocrine signaling has high specificity, low range) |
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Term
paracrine signaling
(specificity, range) |
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Definition
secretes signal extracellularly, diffuses to neighboring molecules
intermediate range, intermediate specificity
(local communication) |
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Term
Endocrine Signaling
(specificity, range) |
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Definition
Hormonal signaling- signals secreted into vasculature, regulates cells very far away(can reach any cell in organism)
Maximal range, minimal specificity
(specificity is aided by receptors on specific cells) |
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Term
| experiments with roosters to determine presence of hormones |
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Definition
castrate roosters- sex characteristics shrink, changes in behavior
replace testes- returns to normal function
transplant testes- normal function
CONTROLS- remove testes and replace before closing (to rule out surgery as cause)
- transplanted into kidney capsules (to see if placement is relevant, if not, hormones are in vasculature) |
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Term
| evidence for autocrine and paracrine signaling |
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Definition
| levels of aromatase (converts testosterone->estradiol) are high in cells that signal with estradiol-receiving cells. They are in close proximity |
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Term
| hair loss(evidence for paracrine/autocrine) |
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Definition
| occurs at hair follicles- local conversion of Testosterone to 5-alpha-DHT results in hair loss |
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Term
| aromatase activity in brain |
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Definition
injection of estradiol causes -> increase aromatase expression in brain-------POSITIVE FEEDBACK
allows animal brains to tolerate increasing levels of estradiol
(cyclical mating seasons) |
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Term
| Intra-nuclear receptor proteins for cell signals |
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Definition
steroid hormones are lipid soluble and can pass through plasma membrane.
binds to intracellular receptor protein-> activating it to bind to DNA-> promoting transcription of a specific gene-> creates protein |
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Term
| extra-cellular (membrane bound) receptor protein signaling |
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Definition
polypeptide or amino-acid derived signals bind to membrane receptors(cannot pass through membrane)
G-protein is activated, diffuses along inside of membrane to alter activity of another enzyme-> leader to cellular response |
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Term
| tyrosine kinase as membrane bound receptor for signaling |
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Definition
| signal activates tyrosine kinase monomers(each with 3 tyrosines) to dimerize-> activation causes each tyrosine(now 6) to be phosphorylated-> each tyrosine activates a different intracellular protein, leading to different responses |
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Term
| ligand gated ion channels |
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Definition
| ligand binds to gated channel, changes conformation opening it to certain ions. concentration of that ion changes in the cell, producing a cellular response. when ligand dissociates, channel closes |
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Term
| membrane receptor signaling and phosphorylation cascade |
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Definition
| signal molecule binds, receptor protein activates relay molecule, activates protein kinase, transfer of phosphate activates second protein kinase, etc.(cascade) to a protein kinase that activates a protein that produces a cellular response |
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Term
| g-protein associated receptor proteins with signaling |
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Definition
| receptor activates g-protein, activates membrane bound adenylyl cyclase, activates second messenger cAMP, activates protein kinase A, producing cellular response |
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Term
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Definition
sensation-> physical transduction of energy from environment to language of organism
perception-> the way the energy is perceptualized by the brain |
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Term
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Definition
depolarization occurs when the inside of the cell becomes more positive than the outside
hyperpolarization occurs when the inside becomes more negative than the outside
at the threshold membrane potential, action potential is triggered by rapid depolarization(to ~+40mV), followed by temporary hyperpolarization before resting potential is restored |
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Term
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Definition
| do not have threshold- stay at graded potential(lack voltage-gated ion channels). transduce signal (many amplify as well) to travel along neural pathways to be integrated |
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Term
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Definition
infrared- snakes can sense warm-blooded prey
magnetoreception- used by for migration(especially important when crossing the equator where the magnetic field reverses)
sonar- used by bats to locate prey in dark |
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Term
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Definition
those that respond to
mechanical disruption(mechanoreceptors)
electromagnetic energy(electro-, magneto-)
wavelengths of light(photo-)
chemical energy(chemo-)
temperature(thermo-)
pain(nociceptive) |
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Term
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Definition
retinal and opsin in membranous discs
retinal changes from cis to trans when activated by light. changes back to cis in the dark |
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Term
| rod cells reaction to light |
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Definition
isomerized retinal activate rhodopsin-> activates G protein Transducin-> actives Phosphodiesterase(PDE) enzyme-> deactivates Na+ ion channels by hydrolyzing cGMP to GMP
rod hyperpolarizes- sends information that light has been absorbed (hyperpolarization stops glutamate release to post-synaptic bipolar cell) |
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Term
| Rods and Cones (and visual illusions) |
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Definition
cones sense different wavelengths of light (accurate)
rods sense light and dark (sensitive)
visual illusions are the difference between sense and perception |
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Term
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Definition
| fluid filled organ surrounded by ciliated receptor cells, contains statolith(chalk granules) that move when balance is upset. transduces information about body motion in aquatic invertebrates |
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Term
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Definition
| 'sound' is transduced from water movements-> moves liquid filled cupula-> moving sensory hair cells |
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Term
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Definition
3 semi-circular canals at different right angles
connected to utricle on top of saccule- telling body which
way is up and down
each canal has an ampulla, containing cupula
movement of endolymph in ampulla does not move with head(ampulla)-> bending the hairs inside the ampulla -> transduced as body movement |
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Term
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Definition
sound waves enter ear and auditory canal, vibrate tympanic membrane-> vibrates malleus, incus, stapes to vibrate oval window(amplification)-> vibrates fluid in chochlea (middle of 3 chambers=organ of corti)
organ of corti contains the hair cells between tectorial membrane and basilar membrane(on bottom)
basilar membrane is stiff and thin at one end(absorbing high frequencies) and wider and more flexible at the other(aborbing low frequencies) |
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Term
binaural cues for auditory localization
coincidence array |
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Definition
sound originates at one side, an interaural distance occurs(difference between when each ear senses the sound)
coincidence array receives information collaterally from right and left auditory nerves (at different times according to position of sound) |
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Term
| surgical uncrossing of frog brain chiasm |
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Definition
tells us that right visual field goes to left brain
relative position remains the same with uncrossing (because only left and right are switched, everything else is the same) |
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Term
| frog skin graft (dorsal to ventral) |
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Definition
itching of belly skin when back skin is stimulated(after 180º skin graft)-> most likely occurs because there is a chemical difference in response of dorsal vs. ventral nerves.
ie. a chemospecificty tells brain if the sensation comes from dorsal or ventral |
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Term
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Definition
skin- tight junctions, sebaceous glands(acidic skin oil)
mucous membranes-
gastric juices, low pH
eyes- lysozyme lyses bacterial walls |
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Term
| non-specific internal immune mechanisms |
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Definition
macrophages-
neutrophils-
eosinophils-
dendritic cells-
clotting cells antimicrobial proteins Apoptosis(programmed DNA degradation-> cell death)
natural killer cells attach to infected cells and signals apoptosis |
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Term
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Definition
interferon(alpha and beta)- limit cell-cell spread of virus
interferon(gamma)- accentuates macrophage activity
defensins- still researching
histamine and chemokines involve in inflammatory response |
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Term
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Definition
chemical signals released by activated macrophages and mast cells-> constrict capillaries at site, dilate those near
antimicrobial proteins and clotting element move to site from blood
chemokines attract more phagocytic cells
neutrophils and macrophages phagocytize pathogen |
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Term
| acquired immunity- antigen recognition |
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Definition
| antigens recognized by epitopes that antibodies bind to |
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Term
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Definition
B lymphocytes recognize epitopes on intact foreign proteins- 2 antigen binding sites- 2 heavy chains and 2 light chains
found in bursa(mature in bone marrow in humans)
T lymphocytes present, and recognize portions of foreign proteins- 1 antigen binding site- alpha chain and beta chain
mature in thymus |
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Term
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Definition
antigen presented on classI MHC recognized by cytotoxic T-cell
kill infected cells
antigen presented on classII MHC(usually on dendritic cell) recognized by helper T-cell-> proliferate
help activate other T cells and B cells |
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Term
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Definition
secondary response faster and higher in amplitude
memory B cells, cytotoxic T cells, helper T cells recognize antigen and launch response |
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Term
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Definition
B-cell proteins bind to antigen- stimulate to divide
some become memory cells
others become plasma cells-> synthesize large amounts of antibodies |
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Term
| humoral vs. cell-mediated |
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Definition
humoral response- antibodies in blood defend against pathogen. Does not form memory cells
ex/ anti-snake venom, anti-rabies
cell-mediated response- defend against infected cells, produces memory B cells, cytotoxic T cells, helper T cells |
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Term
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Definition
| first signal comitting a zygote to a sex-> genetic |
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Term
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Definition
| physiological evidence-> tissue differentiation triggered by hormones secreted from gonad |
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Term
| Sex Determining Region on Y chrom (SRY) |
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Definition
a region on the Y chrom that makes an individual a male- even if translocated to an X chrom
this means that XX individuals with SRY on one X will develop as a male
in animals where heterogametic sex is female, sex-determining region is expected to be on W (ZW)- hasn't been found |
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Term
| aromatase experiment with chicken embryos |
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Definition
inhibition of aromatase (testosterone not converted to estradiol)-> gave rise to almost all male
indicates that being female IS dependent on estrogen, even if sex determining even is creation of ovary (which is usually triggered by genes)
therefore, an injection preventing aromatase activity when gonads are bipotential-> leads to male phenotype
CONTROLS:
if increased testosterone is the cause-
aromatase inhibition along with estradiol injections should still yield male phenotype
if lack of estradiol is the cause-
only inject estradiol, should be female |
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Term
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Definition
in turtles high temp eggs become female
in lizards/alligators high temp eggs become males
temperature variance within nest? |
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Term
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Definition
plumage laterally split(male/female)
correlates with expression of male chrom and female chrom in brain(dose dependence)
-HVC, RA, area X volumes all more male-like(but quite a bit lower)
correlates with testis and ovary(appear healthy and normal)
male-like behavior
sings mating song, copulates, infertile eggs
attacked by male
undetectable levels of estradiol and testosterone
SUGGESTS: neural, not gonadal origin of brain sex differences |
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