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172 Cards in this Set
- Front
- Back
Evidence in favor of evolution (3):
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fossil record,
artificial selection, phylogenetic simlarities |
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Fossils show that cetaceans are most closely related to ____.
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hippos
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_____ between cell walls allow small molecules up to ____ in size to pass between cells without entering the extracellular fluid
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gap junctions, 1.5 nm
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Gap junctions are regulated by a protein called ___
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connexon
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Types of indirect signaling (4):
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autocrine-sender and receiver are same,
paracrine-receiving cell is near the sender, hormonal-hormones travel through bloodstream, synaptic-electrical signals release neurotransmitters |
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Acetylcholine responds based on cell type:
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skeletal muscles-increased contraction,
heart muscles-decreased contraction, salivary glands-increased saliva |
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Phosphorylation occurs on the amino acids ___
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Ser, Tyr, Thr
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Proteins can turn themselves off by ___
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hydrolyzing GTP to make GDP
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Stages of cell signaling (3)
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reception, transduction, response
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Signals for ___ receptors can permeate the plasma membrane because they are ___ (3 examples: ___, ___, ___)
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cytoplasmic, hydrophobic, cortisol, testosterone, estrogen
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___ receptors have extracellular binding domains because their respective ligands are ___ or ___
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Transmembrane, large, hydrophilic
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Thousands of different ___ are known, which have ___ transmembrane segment(s) on the receptor and ___ subunits on the protein
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G-protein coupled receptors (GPCRs), seven, three
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Activated G proteins turn ___ to ___, before breaking apart and releasing __.
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GDP, GTP, GDP
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The second major class of transmembrane receptors ___ have ___[number] transmembrane segment(s)
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Receptor protein-tyrosine kinase (RTK), one
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Ligand binding to RTKs cause ___, which results in ___
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dimerization, auto-phosphorylation on the tyrosine residues
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Two types of ligand-binding dimerization:
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ligand-mediated (single molecule draws monomers together),
receptor-mediated (two molecules draw monomers together) |
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Types of transmembrane receptors (3):
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GPCRs, Enzyme-linked receptors, ion channel receptors
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An important second messenger in transduction is ___, which is created by ___ and cleaved back by ___
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cyclic adenosine monophosphate (cAMP),
adenylate cyclase, cyclic AMP phosphodiesterase |
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G proteins are attached to the membrane by ___
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lipid tethers
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___ discovered cAMP by treating ___ with ___, causing them to ___
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Sutherland, liver cells, epinephrine, break glycogen into glucose
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Sutherland's experiment only worked when he ___, but if he added ___ to ___, it also sometimes worked
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used E+P+S, fractions of E + P, S
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Even in the absence of___, a little cAMP is always made due to ___
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adenylyl cyclase, equilbrium
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Drinking caffeine increases __ levels in the blood
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glucose
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Ca++ pumps into the __, ___, and ___
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extracellular fluid, endoplasmic reticulum, mitochondria
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Ca++ often acts through ___ or ____
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Protein kinase C (PKC), calmodulin (CaM)
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Calmodulin binds ___ and undergoes a conformation change.
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4 Ca++ ions
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Ca++ can cause a cascade called ___, releasing them from the ___, or the ___ in muscle cells, along with releasing
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calcium induced calcium release (CICR),
endoplasmic reticiulum, sarcoplasmic reticulum, ryanodine receptors (RyRs) |
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Ca++ travels through the __
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gap junctions between cells
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In plants, ___ are opened by ___ to allow ___ in and ___ out
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Stomata, guard cells, CO2, water
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The vacuole contains water to maintain ___, along with lots of ___ ions
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turgor pressure, Ca++
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With low turgor pressure, the guard cells ___ and with high pressure, they ___
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close, open
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___ is mutated in about 30% of cancers, preventing ___, which leads to ____
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Ras, hydrolysis of GTP to GDP, continuous cell division
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Viagra inhibits ___, which changes ___ to ___
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cGMP phosphodiesterase, cGMP, GMP
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___ and ___ can change how different cells respond to signals
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divergence, crosstalk
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G-proteins can ____ to deactivate themselves
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spontaneously hydrolyze GTP to GDP
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The chemical ___ patrols the inside of cells to find ___ and then ___ them
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GRK, bound ligands, phosphorylates
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GTP is converted to cGMP by ___, which becomes GMP through the kinase ___
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guanylyl cyclase, cGMP phosphodiesterase
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Proteins are converted to Protein-P by ___, and back to proteins by ___
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kinases, phosphatases
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Termination of Ca++ signals results in __, even though the cell is always ___
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reuptake, pumping out calcium
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Cholera toxin modifies a ___, continuously activating ___, leading to high amounts of ___, causing secretion of ___, with ___ following them
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G-protein, adenylyl cyclase, cAMP, ions, water
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Pheromones:
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chemicals released into the air that affect smell
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Examples of pheromones (3)
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synchronization of menstruation,
dogs marking territory, mate attraction in arthropods |
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Two types of locally transmitted hormones
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autocrine: affects self,
paracrine: affects others |
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The simple endocrine pathway goes ___
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stimulus to endocrine cells to target effectors
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The simple neuroendocrine pathway goes ___
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stimulus to hypothalamus/pituitary to target effectors
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The hormone cascade pathway goes ___
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stimulus to hypothalamus to endocrine cells to target effectors
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The ___ is also called the master gland.
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pituitary gland
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The posterior pituitary acts through a ___ pathway
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neuroendocrine
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ADH is __
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antidieuretic hormone for water resorption in the kidneys
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Oxytocin is ___
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used for releasing milk and stimulating labor contractions
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An increase in blood concentration of ions (___) triggers release of ____ from the ___
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osmolarity, ADH, hypothalamus
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Alcohol prevents release of ___, resulting in ___, which causes ___
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ADH, non-resorption of water, hangovers
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The ___ is controlled almost entirely by the hypothalamus
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anterior pituitary
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The ___ synthesizes lots of hormones, which can act either by a ___ or ___ manner
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anterior pituitary, non-tropic (acts on other endocrine systems),
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The ___ pituitary is directly connected to the hypothalamus, while the ___ is only connected to the portal blood vessels
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posterior, anterior
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___ is a hormone that stimulates milk production and endocrine production of the testes
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prolactin
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___ are hormones that dull the perception of pain
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endorphins
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Growth hormone is tropic/non-tropic, and overexpression leads to ___ while underexpression is ___
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both, gigantism, pituitary dwarfism
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Overproduction of growth hormone in adulthood leads to ___
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acromegaly
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The hypothalamus produces ___, which stimulates production of ___ from the ____, which stimulates production of ____ from the thyroid
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TRH, TSH, anterior hypothalamus, thyroxine, thyroid
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The hormone____ stimulates the metabolic rate and can be triggered by ____
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thyroxine, cold
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There are two forms of thyroxine, ___ and ___, with the thyroid producing mostly ___, which is the active/inactive form,
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T3, T4, T4, inactive form
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Iodine deficiency leads to ___, which cannot turn off the production of ____, causing the thyroid to overwork itself, leading to ___
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production of inactive thyroxine, TRH by negative feedback, goiter
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In the disorder ____, lack of thyroxine can cause ____
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hypothroidism, cretinism
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Goiter can also be caused by ___
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negative feedback mechanisms failing even in high concentrations of thyroxine
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Hyperthyroidism can be caused by ____, in which ___
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Grave's disease, an antibody to the TSH receptor is produced that activates the secretion of thyroxine
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The ____ of the adrenal glands produces ____ and is controlled directly by the ___
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medulla, epinephrine, norepinenphrine, nervous system
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The ___ of the adrenal glands produces ___, and is controlled by hormones, mainly ____ from the ____
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cortex, cortisol, ACTH, anterior pituitary
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Epinephrine and norepinephrine are ____ that are triggered by ___
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catecholamines, tyrosine
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Epinephrine and norepinephrine bind to two types of ___, with norepinehprine binding mostly to ___, while epinephrine binds to ___
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GPCRs, alpha adrenergic, both
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Beta blockers like ___ are used to decrease responses to ___ by ___
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propanolol, epinephrine, preventing the activation of adenylyl cyclase
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Adrenal cortex cells use ___ to produce ____, which ___
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cholesetrol, cortisol, mediates response to stress
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Stress initiates release of ___ from the hypothalamus, stimulating ___ from the ____, stimulating release of ____ from the ____
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CRH, ACTH, anterior pituitary, cortisol, adrenal cortex
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Cortisol causes ___
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unimportant cells to decrease glucose consumption, lower inflammation, and suppression of the immune system
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The gonads produce ___, like ___ for males and ___ for females
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steroids, androgens, progesterone
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The hypothalamus secretes ___, which causes secretion of ____ from the anterior pituitary, which causes secretion of steroids from the gonads
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GnRH, LH and FSH
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____ occurs when the body has ___ chromosomes, causing both male and female traits
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Kleinfelter's syndrome, XXY
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In the pancreas, alpha cells secrete ___ and beta cells ___
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glucagon, insulin
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Insulin directs cells to convert _____ to ____, while glucagon directs them to ___
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glucose, glycogen, release glucose
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Type I diabetes is caused by a lack of ___, while Type 2 is caused by a lack of ___
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insulin, receptors for insulin
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____ is produced by the ___ and helps regulate rhythm of sleep
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melatonin, pineal gland
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Meiosis starts with a ___ cell and ends with four ___ cells
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tetraploid, haploid
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Spermatogenesis results in ___ sperm per original ____
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4, germ cell
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Sperm motility is low under ___ conditions, but ____ conditions activates them
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acidic, basic or neutral
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Spermatogenesis takes place in the ___ by ____, which also produce ____
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seminiferous tubules, Sertoli cells, inhibin
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Testosterone is produced by ____
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Leydig cells
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___ forms over the head of the sperm, containing enzymes to digest the egg
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An acrosome cap
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Sperm are stored in the ___ after production
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epididymis
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Semen is composed of:
___ 2/3rd of the volume is produced by the ____ ____ produced by the ____ ____ produced by the ____ |
sperm;
seminal vesicles; white fluid, prostate; neutralizing solution, bulbourethral glands |
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Puberty increases output of ___ by the hypothalamus, but ___ produced by the ___ exerts negative feedback
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GnRH, inhibin, Sertoli cells
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Mammalian strategies of oogenesis (3):
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intercourse directly stimulates
estrus menstrual cycle |
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During embryogenesis, the oocyte enters ___ of the first meiotic division, and its development is arrested until ___
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prophase, puberty
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The hormones ___ and ____ stimulate follicles to grow and complete ____ until the phase ____, while fertilization stimulates ____
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LH, FSH, Meiosis I, metaphase II, Meiosis II
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____ occurs when the ___ fail to sweep the egg out of the ovaries
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ectopic pregnancies, Fallopian tubes
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The ____ attaches to the wall of the uterus, which is called the ____
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blastocyst, endometrium
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The ___ cycle involves the building up of the endometrium, which starts ____ days into the menstrual cycle
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uterine, 5
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___ days after ovulation, the uterus is maximal and stays that way for ___ days
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5, 9
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In the ovarian cycle, ___ follicles mature each month, but only one continues to grow, for the purpose of ___
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6-12, supplying the egg with nutrients
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After two weeks in the ovarian cycle, ___ occurs, and the ____ ruptures, emitting the egg
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ovulation, follicle
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After ovulation, the follicle forms the ___, which produces __
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corpus luteum, estrogen, progesterone
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On day __ of the ovarian cycle, ___ starts to exert positive rather than negative feedback on the ____, causing a surge of ___ that ruptures the __
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12, estrogen, pituitary, LH and FSH, follicle
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If fertilization occurs, the ___ begins to secrete ___, which maintains the ___, which maintains the ___, allowing for pregnancy tests
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blastocyst, hCG, corpus luteum, endometrium
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During pregnancy, high levels of ___ prevent the secretion of ____, which is what birth control pills use
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progesterone and estrogen, FSH/LH
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___, the birth control hormone, binds to the site where ____ does, but without stimulating it
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RU-486, progesterone
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Drawbacks of external fertilization (6)
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environmental pollution.
can't always choose one's mate. sperm has to find eggs. lots of sperm that compete. many similar species surrounding. polyspermy |
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Problems with polyspermy
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too many chromosomes (Down's syndrome).
messes up early cell divisions |
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__ are model organisms for understanding fertilization
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sea urchins
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For sea urchins, species-specific ____ on the ___ process of sperm interact with the ___ on the eggs
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bindin, acrosomal process, vitellin envelope
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In sea urchins, the fast block to polyspermy is ____
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an influx of Na+ ions that depolarizes the membrane and prevent other sperm from entering
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In sea urchins, the slow block to polyspermy is ____, which stimulates fusion of ____ with ____
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release of Ca++ ions through CICR, cortical granules, plasma membrane
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In sea urchins, fusion of ___ with the plasma membrane causes the ___ to rise and form a ____
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cortical granules, vitelline envelope, fertilization envelope
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Mammalian eggs are surrounded by a ___, under which is a ____, which has species specific ___
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cumulus, zona pellucida, glycoproteins
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Steps of fertilization in mammals (5)
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1. Sperm binds to receptors on zona
2. Acrosome digests a hole in the zona 3. Sperm and egg merge plasma membranes 4. Sperm nucleus enters egg 5. Enzymes raise and harden the zona |
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Old theories of development
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preformation: sperm contains a homunculus
epigenesis: Aristotle thought animals emerge from a formless mass |
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Determination:
Differentiation: Morphogenesis: |
irreversible commitment to differentiation,
expression of developmental commitment, shaping of multicellular organs |
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Transplanting neural ectoderm into an early gastrula results in ___, while transplanting it into a late gastrula results in ___
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nothing different, a second neural plate
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Signals from other cells commit a cell to become skeletal muscle by activating ___, which stimulates production of ___ and blocks ____, leading to multinucleated cells
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myoD, myosin, cell division
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___ says that determination is caused by different developmental determinants in cells divided by mitosis
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Weismann's hypothesis
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___ did experiments on frogs to show that ___ nuclei are ____, and prolonged exposure to an egg environment can revert them to egg-like cells
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Gurdon, somatic, totipotent
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____ cloned sheep by arresting them in the ___ phase and fusing them with eggs from another sheep
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Wilmut et al, G1
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Differentiation in plant cells are more/less easily reversed than in animal cells; carrots can form a mass of cells called a ___ that is completely ___
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more, callus, totipotent
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___ are undifferentiated cells found in adults, but can only divide into some types of cells, so they are called ___
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stem cells, pluripotent
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Stem cells from the ___ of the embryo do not have a developmental identity yet
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inner cell mass
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___ can lead to tremor, weakness, and a blank face, and it is caused by ___ in a region called the ____
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Parkinson's disease, degeneration of dopamine-containing neurons, substantia nigra
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A procedure called ___ involves fusing a cell nucleus with an egg cell to avoid immune rejection
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therapeutic cloning
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Implanting stem cells can cure ___ and ___
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Parkinson's, blindness
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___ is communication between cells that leads to different cell types, either through ____ or ____
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induction, diffusion, cell-to-cell contact
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_____ is when cells commit suicide (___), like in the case of the webbing between the fingers
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programmed cell death, apoptosis
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In Drosophila, there is unequal distribution of ___ like ___, which controls the anterior development, and ____, which controls the posterior
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morphogens, bicoid, nanos
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Determination of the embryonic axes is based on the mother/father
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mother
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Morphogens induce 3 types of segmentation genes:
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gap genes,
pair rule genes, segment polarity genes |
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___ genes define the role of each segment
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homeotic
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____ mutation of the homeotic genes can result in two pairs of wings for fruit flies, while ____ can result in legs growing out of the eyes
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bithorax, antennapedia
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Altered homeotic genes in mice can cause ____ to become ___
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lumbar vertebrae, thoracic vertebrae
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Fruit flies have a ___ bp long gene called a ____, which codes for a ____ amino acid long protein called a ____, which is similar in many organisms
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180, homeobox, 60, homeodomain
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____ families of ___ genes, which consist of ____ genes that reside on different chromosomes, control body differentiation in mice
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4, homeobox, 10
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Darwin concluded that ___ and ___ are related because they have similar larvae
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barnacles, brine shrimp
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___ is retention of juvenile characteristics in the adult
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neoteny
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Humans may be ____ to chimpanzees, because juveniles are similar in that they ____ and ____
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neotonous, have similar head shapes, walk bipedally
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Echinoderm stages of development (6)
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zygote,
eight cells, blastula, gastrula, pluteus larva, adult |
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A bilateral body plan is realized in frogs by the creation of the ____ opposite the point of sperm entry when the ___ rotates
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gray crescent, cortical cytoplasm
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Frog egg cells are split into two hemispheres, the ____, where the sperm always enters, and the ____
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animal, vegetal
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Fertilization of frog eggs activates ___, which phosphorylates ____, allowing it to be degraded, although it is inhibited in the ___ pole
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GSK-3, beta-catenin, vegetal
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In frog eggs, after fertilization, the inhibitor of ____ moves to the gray crescent, where it prevents degradation of ____, so the concentration is higher on the ___ side
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GSK-3, beta-catenin, dorsal
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The distribution of ___ in the gray crescent is maintained with mitotic division, and it turns on genes in the ___ part for differentiation
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beta-catenin, dorsal
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Too little beta-catenin results in ___, while too much in one region results in ____
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no gastrulation, a second axis of embryo formation
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Beta-catenin is called the ____, which turns on gene expression like the transcriptional factors ____
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primary embryonic organizer, Goosecoid, Siamois
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Complete cleavage:
Incomplete cleavage: |
holoblastic, meroblastic
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___ is when cells coalesce into a denser mass of more cells
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compaction
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Blastomeres can separate early, either with ____ or ____, both of which result in identical twins
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2 cell embryos splitting, the inner cell mass splitting
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Ectoderm becomes ____
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nervous system, skin
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Mesoderm becomes ____
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skeleton, gonads, muscles, circulatory system, kidneys
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Endoderm becomes ___
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gut, respiratory tract, liver, pancreas, thyroid, bladder, germ cells
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The blastopore is the opening that later becomes the ___ in vertebrates; the hole is called the ____
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anus, blastocoel
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The first cells to enter the blastopore are called the ___, and they form the ___
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archenteron, primitive gut
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____ showed that the gray crescent is necessary for ____
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Spemann, gastrulation
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In birds and reptiles, cleavage forms a ___ on the yolk, and gastrulation begins when cells move towards it, forming a ____
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blastodisc, primitive streak
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The blastodisc is composed of a ____, which forms the ___, and a ___, which forms the ____
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epiblast, embryo, hypoblast, extraembryonic membrane
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At the forward region of the primitive streak is ____, which ____
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Hensen's node, where cell movements are initiated
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____ is the process by which the ____ thickens above the notochord to create the ___
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neurulation, ectoderm, neural plate
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Neurulation in frogs involves ____ and ____
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spine bifida, folic acid
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Segmentation occurs during ____, when blocks of mesoderm called ____ form on both sides
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neurulation, somites
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____ are model systems for development in vertebrates
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zebrafish
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____ is the development of certain tissues according to proximity to others, like in eyes, when the ____ induces the surface tissue to form a ____, which induces the surface tissue to form the _____
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induction, optic vesicle, lens, cornea
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___ is a model organism for development, because all ___ cells have been traced
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C. elegans, 959 somatic
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In nematodes, a ___ secretes a factor called ____, which induces neighboring cells to become ____
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anchor cell, LIN-3, vulva
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___ originate from the germ layers of the embryo, and they function in exchange of materails
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extraembryonic membranes
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In chickens, a ____ is formed that secretes fluid for shielding the embryo
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amnion
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In humans, after attachment, the ____ separates from the ____ of the blastocyst to form the ____
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inner cell mass, trophoblast, amniotic cavity
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The ____, or the cells at the bottom of the placenta, extends to form the ____, which produces the ____, which has the job of ___
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hypoblast, chorion, placenta, producing estrogen and progesterone after the corpus luteum
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___ was the process by which cells from the amniotic fluid were tested, but a newer technique called ___ allows it to be done earlier
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amniocentesis, chorionic villus sampling
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The neural tube in humans swells into ___ parts that form the ____
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3, brain
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