GCU Bio 182 Exam 3 UPDATED Questions
and CORRECT Answers
First step in a life cycle? - CORRECT ANSWERS Fertilization
Fertilization - CORRECT ANSWERS Sperm penetrates protective layer of egg
Receptors on egg surface bind to molecules on sperm surface
Egg surface prevent polyspermy
Polyspermy - CORRECT ANSWERS fertilization by more than one sperm
Acrosomal Reaction - CORRECT ANSWERS Reaction that is triggered when the sperm
meets the egg. The acrosome tip of the sperm releases hydrolytic enzymes that digest material
around the egg. Actin filaments reach down to connect to sperm-binding receptors. Sodium
rushes to the gaps as the plasma membrane of the sperm and egg fuse to depolarize the voltage of
the plasma membrane. This happens in mere seconds.
Cortical Reaction - CORRECT ANSWERS Slow Block to Polyspermy. Calcium from
cortical granules fill up the gap formulated when the vitelline layer lifts up and detaches from the
egg, ripping off the sperm-binding receptors in the process. The vitelline layer becomes a
fertilization envelope, which acts as a slow block to polyspermy.
What does the rise in calcium within the cytosol aid with? - CORRECT
ANSWERS Increases rates of cellular respiration and protein synthesis, activating the egg
due to rapid changes in metabolism
Proteins and mRNAs are needed for activation, which is already present in the egg. What then
merges? - CORRECT ANSWERS The sperm nucleus and the egg nucleus
Fertilization in Mammals - CORRECT ANSWERS Sperm travels through follicle cell
layer that surrounds the egg. It then reaches the zona pellucida (Ex. matrix), triggering the
cortical reaction. This type of fertilization is relatively slow.
,Developmental Stages - CORRECT ANSWERS Cleavage, Gastrulation, Organogenesis
Cleavage - CORRECT ANSWERS rapid cell division WITHOUT growth. Consists of
formation of blastomeres (smaller cells) and blastocoel once the zygote becomes a blastocoel
Blastocoel - CORRECT ANSWERS fluid-filled cavity of the blastula
Blastula - CORRECT ANSWERS hollow ball of cells
Vegetal Pole - CORRECT ANSWERS More yolk
Animal Pole - CORRECT ANSWERS "animal" part, less yolk
Gray crescent in frogs - CORRECT ANSWERS in frog after fertilization, it becomes gray
crescent; individual cells could develop into a normal frog only if it contained a portion of these
Cleavage in Frog Embryo - CORRECT ANSWERS From 2-cell stage to Blastula. The size
stays the same.
Holoblastic Cleavage - CORRECT ANSWERS Complete division
Little yolk
Sea urchins, frogs, mammals
Meroblastic Cleavage - CORRECT ANSWERS Incomplete division
More yolk (yolk-rich)
Reptiles, birds, egg-laying animals
,What comes after fertilization? - CORRECT ANSWERS Cleavage?
What comes after cleavage? - CORRECT ANSWERS Morphogenesis
Morphogenesis Parts - CORRECT ANSWERS Gastrulation and Organogenesis
Morphogenesis - CORRECT ANSWERS process by which cells occupy their appropriate
locations
Gastrulation - CORRECT ANSWERS movement of cells from the blastula surface to the
interior of the embryo
Organogenesis - CORRECT ANSWERS formation of organs
3-layered embryo (gastrula) - CORRECT ANSWERS Arranged in gastrulation
Has:
Ectoderm, Endoderm, and Mesoderm
Archenteron - CORRECT ANSWERS formed in gastrulation
Becomes digestive tract
Opens through blastopore, which will become the anus
Ectoderm - CORRECT ANSWERS Outer layer
Skin
Nervous system
Jaws and teeth
Germ cells
, Mesoderm - CORRECT ANSWERS middle layer
Bones, muscles, circulatory
Endoderm - CORRECT ANSWERS Inner layer
Lining for digestive tract and for associated organs (liver, pancreas)
Cells continue to move from the frog embryo surface into the embryo by ______. - CORRECT
ANSWERS Involution
After the movement caused by involution, these cells become ) _____ and _______ while the
surface cells will form _______. - CORRECT ANSWERS Endoderm, Mesoderm;
Ectoderm
Human Eggs - CORRECT ANSWERS Very little yolk
Blastocyst
Inner cell mass
Trophoblast
Extraembryonic membranes
Blastocyst - CORRECT ANSWERS Human equivalent of blastula
Inner cell mass - CORRECT ANSWERS cluster of cells at one end of blastocyst
Trophoblast - CORRECT ANSWERS Outer epithelial layer of blastocyst, initiates
implantation, expands and forms extraembryonic membranes
Extraembryonic Membranes - CORRECT ANSWERS Encloses specialized structures
outside embryo. Gastrulation involves inward movement from epiblast through a primitive streak
like a chick embryo.
and CORRECT Answers
First step in a life cycle? - CORRECT ANSWERS Fertilization
Fertilization - CORRECT ANSWERS Sperm penetrates protective layer of egg
Receptors on egg surface bind to molecules on sperm surface
Egg surface prevent polyspermy
Polyspermy - CORRECT ANSWERS fertilization by more than one sperm
Acrosomal Reaction - CORRECT ANSWERS Reaction that is triggered when the sperm
meets the egg. The acrosome tip of the sperm releases hydrolytic enzymes that digest material
around the egg. Actin filaments reach down to connect to sperm-binding receptors. Sodium
rushes to the gaps as the plasma membrane of the sperm and egg fuse to depolarize the voltage of
the plasma membrane. This happens in mere seconds.
Cortical Reaction - CORRECT ANSWERS Slow Block to Polyspermy. Calcium from
cortical granules fill up the gap formulated when the vitelline layer lifts up and detaches from the
egg, ripping off the sperm-binding receptors in the process. The vitelline layer becomes a
fertilization envelope, which acts as a slow block to polyspermy.
What does the rise in calcium within the cytosol aid with? - CORRECT
ANSWERS Increases rates of cellular respiration and protein synthesis, activating the egg
due to rapid changes in metabolism
Proteins and mRNAs are needed for activation, which is already present in the egg. What then
merges? - CORRECT ANSWERS The sperm nucleus and the egg nucleus
Fertilization in Mammals - CORRECT ANSWERS Sperm travels through follicle cell
layer that surrounds the egg. It then reaches the zona pellucida (Ex. matrix), triggering the
cortical reaction. This type of fertilization is relatively slow.
,Developmental Stages - CORRECT ANSWERS Cleavage, Gastrulation, Organogenesis
Cleavage - CORRECT ANSWERS rapid cell division WITHOUT growth. Consists of
formation of blastomeres (smaller cells) and blastocoel once the zygote becomes a blastocoel
Blastocoel - CORRECT ANSWERS fluid-filled cavity of the blastula
Blastula - CORRECT ANSWERS hollow ball of cells
Vegetal Pole - CORRECT ANSWERS More yolk
Animal Pole - CORRECT ANSWERS "animal" part, less yolk
Gray crescent in frogs - CORRECT ANSWERS in frog after fertilization, it becomes gray
crescent; individual cells could develop into a normal frog only if it contained a portion of these
Cleavage in Frog Embryo - CORRECT ANSWERS From 2-cell stage to Blastula. The size
stays the same.
Holoblastic Cleavage - CORRECT ANSWERS Complete division
Little yolk
Sea urchins, frogs, mammals
Meroblastic Cleavage - CORRECT ANSWERS Incomplete division
More yolk (yolk-rich)
Reptiles, birds, egg-laying animals
,What comes after fertilization? - CORRECT ANSWERS Cleavage?
What comes after cleavage? - CORRECT ANSWERS Morphogenesis
Morphogenesis Parts - CORRECT ANSWERS Gastrulation and Organogenesis
Morphogenesis - CORRECT ANSWERS process by which cells occupy their appropriate
locations
Gastrulation - CORRECT ANSWERS movement of cells from the blastula surface to the
interior of the embryo
Organogenesis - CORRECT ANSWERS formation of organs
3-layered embryo (gastrula) - CORRECT ANSWERS Arranged in gastrulation
Has:
Ectoderm, Endoderm, and Mesoderm
Archenteron - CORRECT ANSWERS formed in gastrulation
Becomes digestive tract
Opens through blastopore, which will become the anus
Ectoderm - CORRECT ANSWERS Outer layer
Skin
Nervous system
Jaws and teeth
Germ cells
, Mesoderm - CORRECT ANSWERS middle layer
Bones, muscles, circulatory
Endoderm - CORRECT ANSWERS Inner layer
Lining for digestive tract and for associated organs (liver, pancreas)
Cells continue to move from the frog embryo surface into the embryo by ______. - CORRECT
ANSWERS Involution
After the movement caused by involution, these cells become ) _____ and _______ while the
surface cells will form _______. - CORRECT ANSWERS Endoderm, Mesoderm;
Ectoderm
Human Eggs - CORRECT ANSWERS Very little yolk
Blastocyst
Inner cell mass
Trophoblast
Extraembryonic membranes
Blastocyst - CORRECT ANSWERS Human equivalent of blastula
Inner cell mass - CORRECT ANSWERS cluster of cells at one end of blastocyst
Trophoblast - CORRECT ANSWERS Outer epithelial layer of blastocyst, initiates
implantation, expands and forms extraembryonic membranes
Extraembryonic Membranes - CORRECT ANSWERS Encloses specialized structures
outside embryo. Gastrulation involves inward movement from epiblast through a primitive streak
like a chick embryo.
