Enzymes produced by the sperm’s acrosome
dissolve a hole in the egg’s jelly coat.
List these embryonic events in vertebrates starting
with the earliest.
·
Cleavage; Blastulation; Gastrulation; Neurulation
Gastrulation
is the process that follows cleavage in mammals.
The figure provides an overview of the events of
embryonic development: Fertilization; Cleavage; Gastrulation; Neurulation; Organogenesis
Which of the following are the three germ layers
formed during gastrulation? Endoderm, ectoderm, mesoderm
An organ is a differentiated part of an
organism, such as a wing, that performs a distinct function.
The acrosomal reaction allows the sperm to
penetrate the outer layers of the egg.
Which of the following processes occur during
neurulation? Segmentation of the body; Formation of the CNS
Gastrulation in frogs includes which of the
following events? Appearance of the archenteron
Put the five general development events of
triploblastic animals beginning with the union of the egg and sperm nuclei.
·
Fertilization; Cleavage; Gastrulation; Neurulation;
Organogenesis
Blastomeres
are the cells produced during the cleavage of a zygote.
The primordial germ cells are stem cells that
can divide through mitosis to make copies of themselves. Some of the resulting
daughter cell can later undergo meiosis and differentiate into gametes.
The following structures are formed during
neurulation in vertebrate embryos. Arrange them in order, starting with the
earliest form. Neural plate; Neural groove; Neural tube
In the early stages of vertebrate development, the
process of cleavage yields successive blastomeres that become smaller and
smaller.
Match the germ layer to its appropriate location in
the embryo.
Endoderm: inner layer
Mesoderm: middle layer
Ectoderm: outer layer
The final, adult body plan is organized along three
axes. These are: anteroposterior, dorsoventral, left-right
The developmental event in which cells and tissues
form specialized structures is called: organogenesis
The cortical reaction is characterized by which of
the following? Release of Ca+2 ions from the ER into the cytosol
In humans, the embryo implants in the uterus.
An animal embryo that appears as a hollow ball
formed by many cells at the end of cleavage is called a blastula.
Neurulation in vertebrate embryos occurs in four
major steps. Arrange them in order, starting with the earliest.
1. Thickening
and elongation
2. Folding
3. Convergence
4. Fusion
Which of the following are found in the cytosol of a
human egg, and secrete an enzyme to inactivate the sperm-binding proteins on
the cell membrane? Cortical granules
Complete or holoblastic cleavage of the zygote is
characteristic of which of the following animals? Amphibians, mammals
Incomplete cleavage of the zygote is characteristic
of which of the following animals? Fish, birds
The initial cell cycles of embryos are unique
because they involve repeated cell divisions without cell growth. The process
by which these cell cycles occur is called cleavage
During gastrulation, sheets of surface cells fold
back into the interior of the embryo. This process is called what? Involution
Following cleavage in humans, the hollow ball of
cells that make up the blastocyst develops into a highly organized structure
called the gastrula
Segmentation of an animal embryo begins after
gastrulation during the process of Neurulation.
In mammals, fertilization and cleavage take place in
which of the following structures? Oviduct
Zygote is another term
for the fertilized egg that results from the union of a sperm nucleus and an
egg nucleus.
During implantation in mammals, the embryo
becomes embedded in the endometrium of the mother’s uterus.
The effect of convergent extension during
embryonic development allows the merging of two rows of cells into a single elongated layer.
The notochord begins to form by the end of which
stage of embryonic development? Gastrulation
The invagination of cells perpendicular to
the animal-vegetal axis in frog embryos begins the process of gastrulation.
An embryo is best defined as: an early stage of a
multicellular organism during which the organization of the organism is largely
formed.
The notochord is a flexible rod located
between the digestive tract and the nerve cord in chordate embryos.
As animals develop, cells arrange themselves in
coordinated ways that lead to establishment of a body plan.
In the process of cellular differentiation,
different cells within a developing organism acquire specialized forms and
functions, due to the expression of cell-specific genes.
In the process called implantation, the
blastocyst of a placental animal is embedded into the endometrium of the
uterus.
The effect of apical constriction during embryonic
development causes various cells to elongate.
Cortical
granules are membrane-bound vesicles in the egg’s cytosol that release enzymes
to inactivate the sperm-binding proteins on the plasma membrane.
The early stages of vertebrate development produces cleavage-stage
embryos which divide repeatedly without growth.
The PGCs that give rise to gametes are called
primordial germ cells.
The notochord does not persist in which of the
following adult animals? Mammals, birds
The blastula is the embryonic stage which
consists of an outer layer of epithelial cells and an internal water-filled
cavity.
Order the following steps of fertilization, starting
with the earliest.
1. Acrosomal
reaction
2. Fusion
of membranes of egg and sperm
3. Increase
in inositol trisphosphate (IP3)
4. Ca++
released into cytosol
5. Fusion
of nuclei of egg and sperm
Which of the following statements best describes the
process of cleavage in animal development? The number of embryonic cells
increases, but the overall size of the embryo stays the same.
The transformation of a tadpole into a frog or a
caterpillar is known as metamorphosis.
The process by which different cells within a
developing organism acquire specialized forms and functions, due to the expression
of cell-specific genes, is termed cellular differentiation.
Which of the following are the four tissue types in
animals? Epithelial, connective, nervous, muscle
Which of the following were found to be positive
side effects of the drug thalidomide? Lessens nausea, sleep inducer
The notochord is a mesodermal structure that
provides rigidity along the anteroposterior axis in the dorsal side of the
gastrula.
The two half-size daughter cells produced by each
cell division during cleavage are known as: blastomeres.
The final, adult body plan of most animals is
divided along three axes.
Which of the following are triploblastic animals?
Mollusks, arthropods, echinoderms
The notochord persists in the trunks and tails of
which of the following animals? Amphibians, fish
Metamorphosis
is a profound change in form from one stage to the next in the life of an
organism, e.g. the change of a caterpillar to a butterfly.
The initial cell cycles of embryos are unique
because they involve repeated cell divisions without cell growth. The process
by which these cell cycles occur is called cleavage.
Hox genes are important for establishing structures
along the anteroposterior axis.
Embryonic development is best described as the
process by which a zygote is transformed into an organism with distinct
physiological systems and body parts.
The movement of sheets of cells during embryonic
development is due to convergent extension.
Most modern animals are triploblasts; that
is, they develop from embryos with three germ layers.
In a developing animal, the central, fluid-filled
cavity is called a blastocoel.
The blastocyst is composed of how many layers? 2
Depolarization of the egg membrane blocks other
sperm from binding to egg membrane proteins and is referred to as the fast
block to polyspermy.
During gastrulation in a developing frog embryo, a
new cavity called the archenteron displaces the existing blastocoel.
Placental mammals are also called eutherian.
The four main responses to positional information
are: cell division, cell migration, cell differentiation, and apoptosis.
Metamorphosis occurs after organogenesis and
facilitates the rapid growth of young organisms into mature ones.
The outer epithelial layer of the blastocyst is
called the trophectoderm, which gives rise to the placenta.
