Deck 51: Animal Development

Question 1

The release of calcium ions into the egg cytoplasm during fertilization causes all of the following actions except:

A) an increase in aerobic respiration.
B) onset of the cortical reaction.
C) inhibition of acrosomal enzymes.
D) activation of protein synthesis.
E) onset of a slow block to polyspermy.

Answer 1

C

Question 2

Which of the following is not considered part of the process of morphogenesis per se?

A) Cells become specialized.
B) Cells migrate into specific areas.
C) Certain cells undergo changes in shape.
D) Cells become organized into intricate patterns of tissues and organs.
E) Some cells undergo apoptosis.

Answer 2

A

Question 3

Which of the following statements concerning fertilization is false?

A) Fertilization restores the diploid chromosome number.
B) Fertilization stimulates the initiation of development.
C) Fertilization can determine the sex of the offspring.
D) Fertilization permits the formation of gametes with new genetic combinations.
E) In fertilization, a sperm fuses with an ovum to produce a zygote.

Answer 3

D

Question 4

The fast block to polyspermy involves the:

A) release of inhibitors of acrosomal enzymes.
B) synthesis of a new sperm-resistant membrane.
C) accumulation of calcium ions in the acrosome.
D) opening of ion channels that change the polarity of the egg membrane.
E) destruction of excess bindin receptors on the sperm.

Question 5

In most animals, the sperm and egg contribute an equal __________ to the zygote.

A) amount of cytoplasm
B) number of chromosomes
C) number of enzymes
D) number of mitochondria
E) number of ribosomes

Question 6

Which of the following statements would apply to both the fast block to polyspermy and nerve conductance?

A) The plasma membrane is depolarized.
B) Calcium ions accumulate in the cytoplasm.
C) The sodium-potassium pump maintains the transmembrane potential.
D) A signal transduction pathway opens ion channels.
E) The cytoplasm is positively charged relative to the extracellular space.

Question 7

In sea urchins, the fertilization envelope forms from the:

A) vitelline envelope.
B) jelly coat.
C) zona pellucida.
D) plasma membrane.
E) granulosa cells.

Question 8

Following cleavage of the zygote, which of the following is the first to occur?

A) blastula
B) gastrula
C) neural crest
D) morula
E) primitive streak

Question 9

Which of the following statements about sperm entry is true?

A) The fertilization cone formed by microvilli of the egg membrane contracts and draws the sperm inward.
B) The egg phagocytizes the acrosome of the sperm so it can enter the cell.
C) The cilia on the egg membrane beat and sweep the sperm inside.
D) The sperm releases calcium ions, which make the egg membrane permeable to its entry.
E) The egg secretes bindin protein, which allows sperm penetration.

Question 10

Which of the following consists of a hollow ball of cells?

A) gastrula
B) morula
C) blastula
D) blastocoel
E) zygote

Question 11

Animal growth primarily occurs by an increase in the:

A) number of tissues and organs.
B) number of cells.
C) types of cells produced.
D) number of cell functions.
E) number of cell shapes.

Question 12

Before a sperm can compete in fertilization, it must undergo a maturation process in the female reproductive tract known as:

A) the acrosome reaction.
B) the cortical reaction.
C) spermatogenesis.
D) determination.
E) capacitation.

Question 13

Which of the following indicates the correct sequence of mammalian egg coverings, beginning at the outside and moving inward?

A) plasma membrane, jelly coat, zona pellucida
B) zona pellucida, vitelline envelope, plasma membrane
C) vitelline envelope, plasma membrane, jelly coat
D) granulosa cells, zona pellucida, plasma membrane
E) zona pellucida, granulosa cells, plasma membrane

Question 14

Which of the following indicates the correct sequence of sea urchin egg coverings, beginning at the outside and moving inward?

A) granulosa cells, zona pellucida, plasma membrane
B) zona pellucida, vitelline envelope, plasma membrane
C) jelly coat, vitelline envelope, plasma membrane
D) plasma membrane, jelly coat, zona pellucida
E) vitelline envelope, jelly coat, plasma membrane

Question 15

The principle of nuclear equivalence states that:

A) developing cells become specialized to carry out specific functions.
B) developing cells follow particular differentiation pathways.
C) there is no loss of genetic information through determination or differentiation.
D) differential gene expression is responsible for variation among cells.
E) nuclear changes can take place during the entire life of an individual.

Question 16

During an acrosome reaction, the acrosome:

A) detaches, allowing the sperm to penetrate the egg.
B) releases enzymes that digest the outer layer of the egg.
C) secretes calcium ions, which cause the sperm to fuse with the egg.
D) releases bindin, which causes the sperm to bind to the egg.
E) secretes a chemical that attracts the egg to the sperm.

Question 17

Which of the following is the correct sequence through which early development proceeds?

A) morula $\rightarrow$ zygote $\rightarrow$ gastrula $\rightarrow$ blastula
B) zygote $\rightarrow$ blastula $\rightarrow$ morula $\rightarrow$ gastrula
C) zygote $\rightarrow$ blastula $\rightarrow$ gastrula $\rightarrow$ morula
D) zygote $\rightarrow$ gastrula $\rightarrow$ blastula $\rightarrow$ morula
E) zygote $\rightarrow$ morula $\rightarrow$ blastula $\rightarrow$ gastrula

Question 18

Most invertebrates have:

A) isolecithal eggs and meroblastic cleavage.
B) telolecithal eggs and meroblastic cleavage.
C) isolecithal eggs and holoblastic cleavage.
D) telolecithal eggs and holoblastic cleavage.
E) isolecithal eggs and radial cleavage.

Question 19

Which of the following is not part of the activation program of the egg?

A) increase in aerobic respiration
B) capacitation
C) activation of enzymes
D) increase in protein synthesis
E) completion of meiosis

Question 20

Which the following does not occur in the egg following fertilization?

A) Meiosis II is completed.
B) Microtubules are formed.
C) Calcium concentrations increase.
D) The acrosomal reaction occurs.
E) The cortical reaction occurs.

Question 21

Figure 51-1
Use the figure to answer the corresponding question(s).
The type of cleavage pattern represented in Figure 51-1 is:

A) holoblastic and radial.
B) holoblastic and spiral.
C) meroblastic and radial.
D) meroblastic and spiral.
E) holoblastic and mosaic.

Question 22

The gray crescent region of the amphibian zygote is thought to contain:

A) growth factors and developmental determinants.
B) hormones and ribosomes.
C) yolk and dark pigment granules.
D) mitochondria and ribosomes.
E) neurotransmitters and hormones.

Question 23

The term "archenteron" refers to the developing:

A) gut.
B) lung.
C) notochord.
D) nerve tube.
E) skin.

Question 24

Figure 51-2
Use the figure to answer the corresponding question(s).
The developing embryo in Figure 51-2 is representative of development in:

A) a bird.
B) an annelid.
C) a sea star.
D) a frog.
E) a mammal.

Question 25

Figure 51-2
Use the figure to answer the corresponding question(s).
The structure labeled 3 in Figure 51-2 is the:

A) archenteron.
B) endoderm.
C) mesoderm.
D) blastocoel.
E) ectoderm..

Question 26

The first system to develop in the vertebrate embryo is the:

A) circulatory system.
B) digestive system.
C) excretory system.
D) reproductive system.
E) nervous system.

Question 27

Figure 51-1
Use the figure to answer the corresponding question(s).
Which of the stages or structures in Figure 51-1 was formed by the process of gastrulation?

A) 1
B) f
C) g
D) 3
E) 5

Question 28

Which of the following organisms exhibits meroblastic cleavage?

A) echinoderms
B) amphibians
C) mollusks
D) annelids
E) birds

Question 29

Figure 51-2
Use the figure to answer the corresponding question(s).
The developmental stage represented in Figure 51-2 is:

A) a morula.
B) an early blastula.
C) a late blastula.
D) an early gastrula.
E) a middle gastrula.

Question 30

Figure 51-2
Use the figure to answer the corresponding question(s).
Refer to Figure 51-2.Which structure will form the blastocoel?

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

Question 31

Which of the following occurs during gastrulation?

A) formation of the gray crescent region
B) formation of ectoderm, mesoderm, and endoderm
C) closure of the archenteron
D) formation of the blastocoel
E) radial cleavage takes place

Question 32

Which of the following statements concerning a blastodisc is false?

A) It can be further divided into an upper epiblast and below that, the hypoblast.
B) It results from meroblastic cleavage.
C) It is found in isolecithal eggs.
D) It is a small disc of cytoplasm at the animal pole.
E) It is characteristic of cell division in bird eggs.

Question 33

Embryonic endoderm gives rise to:

A) muscle.
B) the lining of the digestive tract.
C) the nervous system.
D) skin.
E) skeletal tissue.

Question 34

In organogenesis, the ectoderm gives rise to:

A) muscle.
B) the digestive tract.
C) sense organs.
D) the circulatory system.
E) skeletal tissue.

Question 35

Amphibian eggs have large amounts of yolk at the __________ pole, and most metabolism takes place at the __________ pole.

A) animal; vegetal
B) animal; animal
C) vegetal; vegetal
D) vegetal; animal
E) totipotent; telolecithal

Question 36

Embryonic mesoderm forms the:

A) epidermis.
B) lining of the digestive tract.
C) pituitary gland.
D) excretory system.
E) nervous system.

Question 37

Figure 51-1
Use the figure to answer the corresponding question(s).
The structure labeled 2 in Figure 51-1 is the:

A) endoderm layer.
B) mesoderm layer.
C) blastopore.
D) blastocoel.
E) archenteron.

Question 38

A primitive groove is the equivalent of a:

A) neural crest.
B) branchial groove.
C) blastodisc.
D) blastopore.
E) neural groove.

Question 39

Figure 51-2
Use the figure to answer the corresponding question(s).
Refer to Figure 51-2.The nervous system will develop from which structure?

A) 1
B) 2
C) 3
D) 4
E) a structure not numbered in this figure

Question 40

Hensen's node is located:

A) in the walls of the archenteron.
B) at the end of the primitive streak.
C) on the outer side of the chorion.
D) inside a blastomere.
E) inside the neural groove.

Question 41

In mammals, the __________ is a temporary center for the formation of blood cells.

A) amnion
B) allantois
C) yolk sac
D) chorion
E) archenterons

Question 42

Which of the following structures is the last to develop?

A) neural tube
B) neural groove
C) neural crest
D) neural folds
E) neural plate

Question 43

A teratogen is a drug that:

A) increases fertility.
B) prevents fertilization.
C) prevents implantation of the embryo in the endometrium.
D) induces labor.
E) interferes with morphogenesis.

Question 44

Place the following in developmental order beginning with the earliest event. 1)
Limb buds appear
2)
Face begins to look human
3)
Muscles differentiate
4)
Downy hair covers the fetus
5)
Sex can be determined by external inspection

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

Question 45

Monozygotic twins:

A) occur when two eggs are ovulated.
B) may be of different sexes.
C) have different sets of genes.
D) are called identical twins.
E) result from the fertilization of two sperm cells.

Question 46

Which of the following is not an extraembryonic membrane?

A) yolk sac
B) somite
C) chorion
D) amnion
E) allantois

Question 47

The first breath of the neonate is initiated by the:

A) passage through the birth canal.
B) removal of amniotic fluid from its mouth.
C) accumulation of carbon dioxide in the blood.
D) detection of light by its visual receptors.
E) increase in oxygen concentration in the lungs.

Question 48

Which of the following statements about the notochord is false?

A) It is lost when it is replaced by the vertebral column.
B) It develops in chordate embryos.
C) It develops from mesodermal tissue.
D) It induces formation of the neural plate.
E) It grows along the longitudinal axis of the organism.

Question 49

The extraembryonic membrane closest to the embryo is the:

A) amnion.
B) archenteron.
C) chorion.
D) blastocyst.
E) neural plate.

Question 50

Which of the following is not a function of the placenta?

A) exchanges blood between mother and fetus
B) secretes hormones to maintain pregnancy
C) provides oxygen for the fetus
D) eliminates wastes from the fetus
E) provides nutrients for the fetus

Question 51

The trophoblast secretes ______ that signals the corpus luteum that pregnancy has begun.

A) estrogen.
B) a gray crescent.
C) progesterone.
D) hCG.
E) an enzyme.

Question 52

In humans, the allantois:

A) stores embryonic nitrogenous wastes.
B) eliminates nitrogenous wastes from the embryo.
C) contributes to the formation of the blood vessels in the umbilical cord.
D) secretes amniotic fluid.
E) serves as a temporary center for formation of blood cells.

Question 53

Which of the following are incorrectly paired?

A) heroin-premature births and low birth weight
B) thalidomide-babies born without toes
C) accutane-associated with malformations of the brain
D) cocaine-constricts fetal arteries, which leads to retarded development
E) cigarette smoking-an addiction to nicotine

Question 54

All of the following are functions of the extraembryonic membranes except:

A) protecting the embryo.
B) making food available to the embryo.
C) eliminating wastes from the embryo.
D) keeping the embryo dry and warm.
E) obtaining oxygen for the embryo.

Question 55

The percentage of twins being born has increased in the past 20 years because of:

A) the increased use of fertility inducing drugs.
B) increases in hospital care.
C) the desire of more couples to have twins.
D) the increased use of thalidomide.
E) the increased incidence of German measles.

Question 56

Which of the following statements about early embryonic development in humans is false?

A) The embryo is moved along the oviduct by ciliary action and muscular contraction.
B) The embryo develops through the blastula stage while floating free in the uterus.
C) The embryo enters the uterus about 24 hours after fertilization.
D) Early division of the embryo occurs in the oviduct.
E) Implantation of the embryo occurs about seven days after fertilization.

Question 57

Which of the following teratogens is specifically linked to high rates of fetal mortality?

A) heroin
B) thalidomide
C) HIV
D) cocaine
E) ionizing radiation

Question 58

Which of the following structures will be the most immediate precursor of the brain?

A) neural tube
B) neural groove
C) neural crest
D) neural folds
E) neural plate

Question 59

A human embryo is capable of movement and has gonads that are distinguishable as either testes or ovaries by the end of the:

A) second week.
B) fourth week.
C) sixth week.
D) eighth week.
E) first trimester.

Question 60

What is the function of the chorion?

A) to absorb shock
B) to form blood cells
C) to provide nourishment
D) to permit freedom of movement
E) to permit gas exchange

Question 61

Inside the zona pellucida is a layer of granulosa cells.
____________________

Question 62

Programmed cell death is called apoptosis.
____________________

Question 63

Gastrulation is the process by which an embryo becomes three-layered.
____________________

Question 64

In the amphibian embryo, the first cleavage bisects the gray crescent.
____________________

Question 65

The chorion is the extraembryonic membrane closest to the embryo proper.
____________________

Question 66

Compare and contrast the roles of cell division and morphogenesis in the development of an animal.

Question 67

Identify two changes that occur at or shortly after birth that allow the neonate to live independently.

Question 68

In birds and reptiles, the allanotois stores nitrogenous wastes.
____________________

Question 69

During capacitation, sperm become mature.
____________________

Question 70

The eggs of birds and reptiles are telolecithal.
____________________

Question 71

In echinoderms, gastrulation takes place through a primitive groove.
____________________

Question 72

Human chorionic gonadotropin signals the placenta to produce large amounts of estrogen and progesterone.
___________________

Question 73

As part of the fertilization process, the egg completes meiosis I.
____________________

Question 74

The notochord induces the neural plate.
____________________

Question 75

Isolecithal eggs exhibit holoblastic cleavage.
____________________

Question 76

The fertilization envelope forms during the acrosomal reaction.
____________________

Question 77

The blastopore is the opening to the blastocoel.
____________________

Question 78

When a human embryo is implanted in the uterus, the embryo is in the morula stage.
____________________

Question 79

The morula can be described as an embryo consisting of a hollow sphere of cells.
____________________

Question 80

An embryo having a blastodisc exhibits holoblastic cleavage.
____________________