Deck 52: Animal Development

Question 1

The process by which a fertilized egg becomes a distinct organism is called

A) epigenesis.
B) cellular dedifferentiation.
C) involution.
D) embryonic development.
E) metamorphosis.

Answer 1

embryonic development.

Question 2

The specific process by which a swimming tadpole transforms into an adult frog with distinct limbs is called

A) epigenesis.
B) cellular dedifferentiation.
C) gastrulation.
D) involution.
E) metamorphosis.

Answer 2

metamorphosis.

Question 3

Most organisms develop from the embryonic gastrula that is composed of ________ germ cell layer(s)?

A) 1
B) 2
C) 3
D) 4
E) 5

Answer 3

3

Question 4

During which stage of development are germ cell layers first formed?

A) fertilization
B) cleavage
C) neurulation
D) gastrulation
E) organogenesis

Question 5

Once an egg has been fertilized, what event(s) are crucial for preventing additional sperm from inserting chromosomes into the egg?

A) the acrosomal reaction
B) the cortical reaction
C) the fast block to polyspermy
D) both the acrosomal and cortical reactions
E) both the cortical reaction and fast block to polyspermy

Question 6

Which of the following events involves the release of enzymes?

A) cell cleavage
B) cortical reaction
C) egg membrane depolarization
D) increase in cytosolic calcium within the egg
E) the fusion of egg and sperm nuclei

Question 7

Which of the following sequence of events of fertilization is in the proper order?

A) acrosomal reaction, binding of sperm to egg membrane, fast block to polyspermy, increase in egg cytosolic calcium, and then the slow block to polyspermy
B) binding of sperm to egg membrane, acrosomal reaction, fast block to polyspermy, slow block to polyspermy, and then an increase in egg cytosolic calcium
C) binding of sperm to egg membrane, acrosomal reaction, fast block to polyspermy, increase in egg cytosolic calcium, and then the slow block to polyspermy
D) acrosomal reaction, fast block to polyspermy, binding of sperm to egg membrane, increase in egg cytosolic calcium, and then the slow block to polyspermy
E) acrosomal reaction, fast block to polyspermy, binding of sperm to egg membrane, slow block to polyspermy, and then an increase in egg cytosolic calcium

Question 8

The increase in cytosolic calcium within the egg during fertilization initiates

A) the slow block to polyspermy.
B) the cortical reaction.
C) signaling for the first cell division.
D) the release of enzymes by the egg.
E) All of the choices are correct.

Question 9

Which of the following is TRUE of cell cleavage?

A) It involves consecutive cycles of cell division without cell growth.
B) It forms a blastula.
C) It is a rather slow event of embryonic development.
D) It involves consecutive cycles of cell division without cell growth and forms a blastula.
E) It is a rather slow event of embryonic development involving consecutive cycles of cell division.

Question 10

Birds and fish contain high amounts of yolk in their eggs. What can be said about cell cleavage during embryonic development in these animals?

A) It is meroblastic.
B) It is holoblastic.
C) It is complete.
D) The blastula that forms involved cleavage through the entire egg.
E) It is impossible for bird and fish eggs to undergo cleavage during development.

Question 11

________ is the inner most germ cell layer that forms during gastrulation.

A) Ectoderm
B) Mesoderm
C) Endoderm
D) Mesentery
E) Epidermis

Question 12

Which embryonic structure ultimately forms the digestive tract?

A) archenteron
B) blastopore
C) blastocoel
D) notochord
E) convergence extension

Question 13

The ectoderm is to the central nervous system as the mesoderm is to the

A) epidermis.
B) respiratory tube.
C) digestive tract.
D) skeletal muscle.
E) peripheral nervous system.

Question 14

During gastrulation, the cellular process by which ectoderm in the animal pole spreads toward the vegetal pole is called

A) epiboly.
B) invagination.
C) involution.
D) convergent extension.
E) apical constriction.

Question 15

Which of the following is NOT an outcome of neurulation?

A) establishment of cells that will form future pigment cells and certain facial bones
B) establishment of the central nervous system
C) establishment of the neural crest
D) establishment of the archenteron
E) establishment of somites

Question 16

Cadherin proteins are specifically associated with which of the following during embryonic development?

A) the differentiation of the archenteron
B) anterioposterior axis formation
C) maintenance of different germ cell layers through specific cell-to-cell contacts
D) establishment of a morphogenic field
E) limb cell differentiation

Question 17

Which factor is important for maintaining the different germ cell layers in the developing embryo? [Hint: without this molecule the embryo would be a ball of cells with no distinct germ cell layers.]

A) activin
B) noggin
C) Spemann's organizer
D) Hox gene
E) cadherins

Question 18

The anterioposterior axis of an embryo is established by

A) activin.
B) Hox genes.
C) cadherins.
D) noggin.
E) transforming growth factor.

Question 19

Which of the following is TRUE of a morphogen?

A) It is a signaling molecule required for cell-to-cell contact within the embryo.
B) It is a signaling molecule that induces the differentiation of cells within the embryo.
C) It is a signaling molecule that induces blastulation of the developing embryo.
D) It is a signaling molecule that induces implantation of the embryo into the uterus of mammals.
E) It is a signaling molecule that separates out cytoplasmic factors to their respective cells within the developing embryo.

Question 20

Which of the following is important to the development of dorsal structures such as the neural tube and notochord?

A) Spemann's organizer
B) noggin
C) cadherins
D) both Spemann's organizer and noggin
E) both Spemann's organizer and cadherins

Question 21

Which of the following is TRUE of fate mapping?

A) It determines the ultimate structure/function of a particular cell type during embryonic development.
B) It maps the genes of an embryo.
C) It assesses the quality of a developing embryo.
D) It maps the proteins within a morphogenic field.
E) It determines hereditable disorders in the embryo.

Question 22

Through studies using the animal cap assay this morphogen was shown to be important for the determination of the different types of mesoderm tissue in the developing embryo.

A) activin
B) noggin
C) Spemann's organizer
D) Hox gene
E) cadherins

Question 23

Hans Spemann and Hilde Mangold conducted pioneering experiments in which they transplanted the dorsal lip of the blastopore in an early gastrula newt to the ventral side of another early gastrula newt. What was the outcome of this experiment?

A) Discovery of Spemann's organizer.
B) The development of dorsal structures (neural tube, notochord) on both the dorsal and ventral parts of the gastrula that received the transplant.
C) Identification of a morphogenic field in the dorsal lip of the blastopore of an early gastrula.
D) Discovery of a group of embryonic cells in the dorsal lip that ultimately produce specific body structures.
E) All of the choices are correct.

Question 24

Which of the following is NOT a morphogen?

A) activin
B) noggin
C) Wnt
D) cadherin
E) protein produced by Spemann's organizer (dorsal lip of a gastrula)

Question 25

Which are likely involved in promoting cell differentiation during animal development?

A) differential distribution of cytosolic factors among early embryonic cells
B) extracellular signals
C) cellular receptors
D) specific morphogens
E) All of the choices are correct

Question 26

The two primary mechanisms of cell differentiation are conditional specification and

A) fertilization.
B) gastrulation.
C) autonomous specification.
D) polar cap fusion.
E) organogenesis.

Question 27

It is well established that developmental biology has impacts on public health. For instance, thalidomide, an anticonvulsive and antihistimine medication, was prescribed to reduce nausea or morning sickness in pregnant women. It was subsequently shown to cause severely deformed limbs (hands and feet, but reduced arms and legs) in children whose mothers took the medication. What might thalidomide do during development?

A) Cause a defect in the fertilization of an egg.
B) Severely alter blastulation in the embryo.
C) Impair morphogenic fields within the embryo.
D) Impair neural tube formation.
E) Block cell division during blastulation.

Question 28

Which of the following is likely required to initiate cell differentiation during development?

A) cell division
B) the presence of certain mRNAs needed for expression of cell-specific proteins
C) the buildup of cell-to-cell adhesion molecules
D) the presence of carbohydrates
E) hydration of the egg during fertilization

Question 29

The fast block to polyspermy occurs through a rapid increase in cytosolic calcium within the egg.

Question 30

Most of the egg yolk found in certain vertebrates is restricted to the animal pole?

Question 31

The neural tube or spinal chord is derived from mesoderm.

Question 32

Fate mapping is a valuable tool to establish the type of cells derived from certain undifferentiated cells within an early embryo.

Question 33

Chicken eggs form a blastula through holoblastic cleavage.

Question 34

One outcome of gastrulation is the establishment of primordial germ cells, which represent the cell types that form gametes.

Question 35

Convergent extension, involution, and invagination are ways in which cells move and transform within the embryo.

Question 36

The differentiation of cells into distinct body parts is induced by morphogens.