Bio 200 Exam 4 Questions with Correct
Answers
membrane signal receptors - ANSWER-bind to intercellular protein and change the
shape/function of the protein.
the protein then releases a signal which could be a protein or something else that
starts the amplification of the signal to secondary messengers and intracellular
signals.
the signal that was outside of the cell doesn't physcially move into the cell.
cleavage - ANSWER-rapid cell division after fertilization, proliferation
cells get smaller (no time for development or growth)
radial cleavage - ANSWER-divide vertically in a cylinder shape, a strong axis (done
in humans)
spiral cleavage - ANSWER-asymmetric mitosis (some small and some big cells)
(done in snails)
discoidal cleavage - ANSWER-horizontal axis. Plate of cells dividing on the yolk. All
cells want access to yolk for nourishment
superficial cleavage - ANSWER-nuclei divide a bunch, don't wait for telophase (so
cytoplasm never divides) (happens in flies)
blasomeres - ANSWER-cells that are created during cleavage
blastocyst - ANSWER-type of blastula, two populations of cells
trophoblast (exterior, for feeding), fluid cavity and ICM
trophoblast becomes organ called placenta, ICM becomes embryo
gastrulation - ANSWER-cell movement after proliferation.
highly organized movements and changes in cell shape
surface cells move inward to form 3 germ layers
fluid filled interior space, indentation forms on outer surface and becomes
blastopore. Cells from surface fold into the interior of the embryo through the
, blastopore. Forms a tube that will become the diegestive tract. The movement forms
3 layers (endoderm, mesoderm, and ectoderm)
ectoderm - ANSWER-froms the outer covering of the body
nervous system
mesoderm - ANSWER-muscle, internal organs, connective tissues, bone and
cartilage
endoderm - ANSWER-inner lining of digestive tract, th gut, liver and lungs
setting the axis of the embryo - ANSWER-the region where cells first move into the
blastopore defies the dorsal/back of the embryo
axis are determined by cytoplasmic determinants or through cell-cell
interaction/induction
*differential gene expression
gametogenesis - ANSWER-occurs in response to environmental cues that indicate
breeding is favorable
chemical signals cordinate gamete release
sperm competition/second male advantage - ANSWER-competition between sperm
from different males to fertilize the eggs of the same female
whichever male was last to copulate fathered most of the offspring
sperm of the second male can physically dislodge the other sper,
females can eject sperm from their reproductive tracts
how do sperm find eggs and fertilize them? - ANSWER-drawn in by chemical
gradient
head of sperm binds to jelly layer
binding releases the acrosome contents
enzymes in the acrosome digest the jelly layer
sperrm digests jelly until it comes in contact with the plasma membrane of the egg
and proteins fuse them
spem nucleus enters the egg, nuclei fuse and fertilization is complete
** as sperm move up the concentration gradient they have directed movement for a
short time each time them come in contact with a ligand. (actin filaments help move
the sperm to the membrane of the oocyte)
Answers
membrane signal receptors - ANSWER-bind to intercellular protein and change the
shape/function of the protein.
the protein then releases a signal which could be a protein or something else that
starts the amplification of the signal to secondary messengers and intracellular
signals.
the signal that was outside of the cell doesn't physcially move into the cell.
cleavage - ANSWER-rapid cell division after fertilization, proliferation
cells get smaller (no time for development or growth)
radial cleavage - ANSWER-divide vertically in a cylinder shape, a strong axis (done
in humans)
spiral cleavage - ANSWER-asymmetric mitosis (some small and some big cells)
(done in snails)
discoidal cleavage - ANSWER-horizontal axis. Plate of cells dividing on the yolk. All
cells want access to yolk for nourishment
superficial cleavage - ANSWER-nuclei divide a bunch, don't wait for telophase (so
cytoplasm never divides) (happens in flies)
blasomeres - ANSWER-cells that are created during cleavage
blastocyst - ANSWER-type of blastula, two populations of cells
trophoblast (exterior, for feeding), fluid cavity and ICM
trophoblast becomes organ called placenta, ICM becomes embryo
gastrulation - ANSWER-cell movement after proliferation.
highly organized movements and changes in cell shape
surface cells move inward to form 3 germ layers
fluid filled interior space, indentation forms on outer surface and becomes
blastopore. Cells from surface fold into the interior of the embryo through the
, blastopore. Forms a tube that will become the diegestive tract. The movement forms
3 layers (endoderm, mesoderm, and ectoderm)
ectoderm - ANSWER-froms the outer covering of the body
nervous system
mesoderm - ANSWER-muscle, internal organs, connective tissues, bone and
cartilage
endoderm - ANSWER-inner lining of digestive tract, th gut, liver and lungs
setting the axis of the embryo - ANSWER-the region where cells first move into the
blastopore defies the dorsal/back of the embryo
axis are determined by cytoplasmic determinants or through cell-cell
interaction/induction
*differential gene expression
gametogenesis - ANSWER-occurs in response to environmental cues that indicate
breeding is favorable
chemical signals cordinate gamete release
sperm competition/second male advantage - ANSWER-competition between sperm
from different males to fertilize the eggs of the same female
whichever male was last to copulate fathered most of the offspring
sperm of the second male can physically dislodge the other sper,
females can eject sperm from their reproductive tracts
how do sperm find eggs and fertilize them? - ANSWER-drawn in by chemical
gradient
head of sperm binds to jelly layer
binding releases the acrosome contents
enzymes in the acrosome digest the jelly layer
sperrm digests jelly until it comes in contact with the plasma membrane of the egg
and proteins fuse them
spem nucleus enters the egg, nuclei fuse and fertilization is complete
** as sperm move up the concentration gradient they have directed movement for a
short time each time them come in contact with a ligand. (actin filaments help move
the sperm to the membrane of the oocyte)
