Deck 50: Animal Development

Question 1

As cleavage divisions continue, the ball or layer hollows out to form the ____.

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

Answer 1

D

Question 2

Yolk, when unequally distributed in the egg cytoplasm, is most commonly concentrated in the ____ half of the egg.

A) cleavage
B) gastrulation
C) animal
D) vegetal
E) embryonic

Answer 2

D

Question 3

Human development ____.

A) is complete at birth
B) begins at puberty
C) is complete at puberty
D) occurs only during adult life
E) begins at conception

Answer 3

E

Question 4

Cleavage-stage cells are called ____; they initially form a solid ball or layer called a ____.

A) morulas; blastomere
B) blastocoels; blastomere
C) blastomeres; morula
D) blastomeres; blastula
E) blastulas; blastocoel

Question 5

Uterine contractions ____.

A) often occur during the second trimester
B) are controlled by negative feedback
C) are controlled by positive feedback
D) are stimulated by the hormone prolactin
E) only occur during the first two stages of labor

Question 6

Morphology refers to the ____ of an organism.

A) reproductive ability
B) form or shape
C) habitat
D) lifespan
E) movement

Question 7

During mitotic cleavage. ____.

A) no cell division occurs and the embryonic mass does not change
B) no cell division occurs and the embryonic mass increases
C) cell division occurs and the embryonic mass does not change
D) cell division occurs and the embryonic mass increases
E) the cell is in a dormant stage

Question 8

How does the amount of yolk relate to the nourishment of the organism?

A) An egg with a small amount of yolk contains all of the nutrients for the embryo's development.
B) An egg with a large amount of yolk contains all of the nutrients for the embryo's development.
C) An egg lacking yolk contains all of the nutrients for the embryo's development.
D) There is no relationship between the amount of yolk and the nourishment of the organism.
E) All animal eggs have the same amount of yolk and provide the same amount of nourishment.

Question 9

The final body form of an animal is generated as differentiated cells settle into their appropriate sites; this process is called ____.

A) fertilization
B) morphogenesis
C) parturition
D) involution
E) gastrulation

Question 10

Before zygotic genes become active, the stages of animal development are directed by the ____.

A) environment
B) cytoplasmic determinants of the egg
C) cytoplasmic determinants of the sperm
D) cytoplasmic determinants of the egg and the sperm
E) zygote nucleus

Question 11

The information directing the development of the fertilized egg is provided by ____.

A) the egg nucleus only
B) the sperm nucleus only
C) mRNAs in the egg cytoplasm only
D) proteins in the egg and sperm cytoplasm
E) the egg and sperm nuclei, mRNAs in the egg cytoplasm, and proteins in the egg cytoplasm

Question 12

As embryonic cells divide during cleavage, the daughter cells ____.

A) grow to the same size as the parent cell
B) become progressively smaller
C) become progressively larger
D) are different in size from each other and the parent cell
E) may increase or decrease in size depending on their position

Question 13

Compared to other mammals, the human brain is unique with respect to its ____.

A) integrative capacity only
B) degree of complexity only
C) pathway of embryonic development only
D) integrative capacity and degree of complexity
E) integrative capacity, degree of complexity, and pathway of embryonic development

Question 14

The correct sequence of embryonic development is ____.

A) gastrulation, organogenesis, and fertilization
B) cleavage, gastrulation, and organogenesis
C) gastrulation, fertilization, and organogenesis
D) gastrulation, cleavage, and organogenesis
E) fertilization, organogenesis, and cleavage

Question 15

Most of the mRNA and protein molecules in the zygote are from the ____ because ____.

A) mother; the fertilizing sperm contributes essentially no cytoplasm to the zygote
B) mother; the fertilizing sperm contributes essentially no DNA to the zygote
C) mother; the proteins in the egg degrade mRNA and protein molecules contained in the sperm
D) father; the egg contributes essentially no cytoplasm to the zygote
E) father; the egg contributes essentially no DNA to the zygote

Question 16

Unequal distribution of yolk and other components in a mature egg is termed ____.

A) cleavage
B) gastrulation
C) involution
D) neurulation
E) polarity

Question 17

Eggs from which organism contain the lowest percentage of yolk?

A) birds
B) humans
C) insects
D) reptiles
E) moths

Question 18

At the cellular level, the development of an adult animal from a fertilized egg involves ____.

A) mitosis only
B) meiosis only
C) cell differentiation only
D) mitosis, cell differentiation, and morphogenesis
E) meiosis, cell differentiation, and morphogenesis

Question 19

In an egg, the ____ pole typically gives rise to surface structures and the anterior end of the embryo, while the ____ pole gives rise to internal structures, such as the gut and the posterior end of the embryo.

A) cleavage; gastrulation
B) gastrulation; animal
C) animal; vegetal
D) cleavage; embryonic
E) vegetal; animal

Question 20

At the cellular level, the development of an animal from a fertilized egg involves cell division by _____.

A) meiosis
B) mitosis
C) differentiation
D) morphogenesis
E) cloning

Question 21

Muscles originate from the ____.

A) ectoderm only
B) endoderm only
C) mesoderm only
D) ectoderm and endoderm
E) ectoderm and mesoderm

Question 22

In sea urchins, the primary mesenchyme cells eventually become the ____.

A) ectoderm
B) endoderm
C) mesoderm
D) endoderm and mesoderm
E) ectoderm and endoderm

Question 23

The blastopore is the ____.

A) opening of the archenteron at the animal pole
B) opening of the archenteron at the vegetal pole
C) outer layer of the blastula
D) cavity in the blastula formed by invagination
E) region of the blastula establishing dorsal-ventral polarity

Question 24

Cells capable of producing all the various types of cells of the adult are called ____ cells.

A) semipotent
B) pluripotent
C) totipotent
D) multipotent
E) differentiated

Question 25

In sea urchin embryogenesis, the mouth is formed ____.

A) where the archenteron contacts the ectoderm
B) by the blastopore
C) by the blastocoel
D) by migrating secondary mesenchyme cells
E) where the blastopore contacts the ectoderm

Question 26

Place the three primary cell layers of an embryo in order from superficial to deep.

A) ectoderm → endoderm → mesoderm
B) ectoderm → mesoderm → endoderm
C) endoderm → ectoderm → mesoderm
D) endoderm → mesoderm → ectoderm
E) mesoderm → ectoderm → endoderm

Question 27

In ____, one group of cells causes or influences another nearby group of cells to follow a particular developmental pathway.

A) apoptosis
B) induction
C) differentiation
D) determination
E) cleavage

Question 28

During ____, the three germ layers rearrange to produce tissues and organs.

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

Question 29

Apoptosis is ____.

A) cell determination
B) cell induction
C) a mechanism of cellular adhesion
D) programmed cell death
E) cell differentiation

Question 30

Place the cellular processes responsible for animal development in the correct order.

A) induction → differentiation → determination
B) induction → determination → differentiation
C) determination → induction → differentiation
D) determination → differentiation → induction
E) differentiation → determination → induction

Question 31

Which group of organisms has a pattern of gastrulation that is the most similar to humans?

A) amphibians
B) birds
C) drosophila
D) sea urchins
E) zebra fish

Question 32

During gastrulation in frog embryos, cells migrate into the blastopore by a process called ____.

A) invagination
B) involution
C) cleavage
D) induction
E) adhesion

Question 33

In bird embryos, the pathway for cell migration into the blastocoel is formed by the ____, while in frog embryos, the pathway for cell migration into the blastopore is formed by the ____.

A) archenteron; dorsal lip of the blastopore
B) epiblast; dorsal lip of the blastopore
C) primitive groove; ventral lip of the blastopore
D) primitive groove; dorsal lip of the blastopore
E) hypoblast; ventral lip of the blastopore

Question 34

During the process of ____, blastomeres undergo extensive cellular rearrangements to produce an embryo with three distinct primary cell layers.

A) induction
B) cleavage
C) organogenesis
D) metamorphosis
E) gastrulation

Question 35

In ____, the gray crescent establishes the ____ axis of the body.

A) birds; dorsal-ventral
B) frogs; dorsal-ventral
C) humans; dorsal-ventral
D) birds; anterior-posterior
E) sea urchin; anterior-posterior

Question 36

The epidermis of the skin and the lens, cornea, and retina of the eye   originate from the ____, while the lining of the respiratory tract originates from the ____.

A) ectoderm; endoderm
B) ectoderm; mesoderm
C) endoderm; ectoderm
D) endoderm; mesoderm
E)

Question 37

Arrange the developmental stages in the proper order.

A) blastula → gastrula → morula
B) blastula → morula → gastrula
C) gastrula → blastula → morula
D) morula → blastula → gastrula
E) morula → gastrula → blastula

Question 38

Which group of adult tissues is derived from the mesoderm?

A) lining of the digestive tract, liver, pancreas
B) muscles, bones, cartilage
C) skin, brain, retina
D) skin, liver, pancreas
E) lining of respiratory tract, thyroid gland, urinary bladder

Question 39

During gastrulation in sea urchins, invagination produces a cavity called the ____.

A) archenteron
B) primary mesenchyme
C) secondary mesenchyme
D) blastocoel
E) blastocyst

Question 40

During frog gastrulation, cells of the ____ of the blastopore control blastopore formation.

A) blastocoel
B) archenteron
C) hypoblast
D) dorsal lip
E) blastodisc

Question 41

In vertebrates, cells of the neural crest develop into ____.

A) bones of the inner ear only
B) cartilage of the face only
C) cranial nerves only
D) muscles of the chest and cranial nerves
E) bones of the inner ear, cartilage of the face, and cranial nerves

Question 42

When the SRY gene of the Y chromosome becomes active (around seven weeks), the ____.

A) Müllerian and Wolffian ducts both develop into male reproductive structures
B) Müllerian ducts develop into male reproductive structures and the Wolffian ducts disappear
C) Müllerian ducts disappear and the Wolffian ducts develop into male reproductive structures
D) Müllerian and Wolffian ducts both disappear
E) Müllerian and Wolffian ducts both develop into female reproductive structures

Question 43

Which event occurs in a human fetus with the XX combination of sex chromosomes?

A) Anti-Müllerian hormone is produced.
B) The SRY gene is activated.
C) Testosterone is secreted.
D) The Wolffian ducts develop.
E) The gonads develop into ovaries.

Question 44

What determines the development of male or female sex organs in the human embryo?

A) environmental factors
B) genes on the X chromosome
C) genes on the Y chromosome
D) genes on both the X and Y chromosomes
E) neither the X nor Y chromosomes

Question 45

After childbirth, ____ in the mother.

A) oxytocin stimulates the production and secretion of milk
B) oxytocin stimulates the production of milk and prolactin stimulates the secretion of milk
C) prolactin stimulates the production and secretion of milk
D) prolactin stimulates the production of milk and oxytocin stimulates the secretion of milk
E) estrogen and progesterone are directly responsible for the production and secretion of milk

Question 46

Normally, gestation lasts for approximately ____ weeks in humans.

A) 28
B) 38
C) 44
D) 50
E) 60

Question 47

In vertebrates, organogenesis begins with ____.

A) neurulation
B) gastrulation
C)   fertilization
D) determination
E) differentiation

Question 48

As the period of fetal growth comes to an end, a steep rise in ____ levels directly causes ____.

A) progesterone; uterine cells to express oxytocin receptor genes
B) progesterone; uterine contractions
C) estrogen; uterine cells to express oxytocin receptor genes
D) estrogen; uterine contractions
E) estrogen; oxytocin production

Question 49

Determination ____, while differentiation ____.

A) is a cell's commitment to a developmental fate; is a cell's development into specialized cell types
B) is a cell's development into specialized cell types; is a cell's commitment to a developmental fate
C) is permanent; is reversible
D) is a result of a cell's own genetic program; is a result of influence by other cells
E) results in the final fate of a cell; results in determination

Question 50

In vertebrates, the central nervous system develops directly from the ____.

A) somites
B) neural plate
C) notochord
D) cells of the neural crest
E) neural tube

Question 51

When the optic vesicle contacts overlying ectoderm, developmental events are induced, leading to ____ in the developing lens.

A) crystallin and keratin synthesis
B) crystallin synthesis
C) keratin synthesis
D) degradation of crystalline and keratin
E) apoptosis

Question 52

The extraembryonic membrane that secretes fluid around the developing embryo is the ____.

A) allantois
B) amnion
C) chorion
D) yolk sac
E) both the allantois and the yolk sac

Question 53

The chorion is produced from which primary tissue layer(s)?

A) ectoderm and endoderm
B) ectoderm and mesoderm
C) endoderm and mesoderm
D) ectoderm only
E) endoderm only

Question 54

Normally, human fertilization occurs in the ____.

A) vagina
B) cervix
C) ovary
D) uterus
E) oviduct

Question 55

The pharyngeal arches contribute to the formation of the ____.

A) brain and spinal cord
B) heart
C) legs and arms
D) lungs
E) larynx and pharynx

Question 56

Genetic testing performed on cells of the placenta is called ____, while a similar procedure that uses cells derived from the amniotic fluid is called ____.

A) placenta sampling; chorionic villus sampling
B) trophoblast testing; amniocentesis
C) trophoblast testing; chorionic villus sampling
D) chorionic villus sampling; amniocentesis
E) placenta sampling; amniocentesis

Question 57

The outer single layer of cells of the blastocyst is called the _____.

A) gastrula
B) trophoblast
C) inner cell mass
D) endometrium
E) zona pellucida

Question 58

During early embryonic development, implantation into the uterine lining occurs at the ____ stage.

A) zygote
B) morula
C) blastocyst
D) gastrula
E) hypoblast

Question 59

A human embryo is first considered to be a fetus at ____ weeks.

A) 2
B) 4
C) 8
D) 10
E) 12

Question 60

Which structure of the eye is matched appropriately with its developmental origin?

A) ectoderm → cornea
B) crystallin → cornea
C) optic cup → lens
D) crystallin → retina
E) mesoderm → retina

Question 61

When a dorsal lip from a newt is attached to the ventral side of another embryo, it results in ____.

A) two separate newts
B) two attached newts
C) survival of only the original newt
D) death of the newt
E) no observable result

Question 63

Apoptosis begins when ____ is inactivated.

A) CED-3
B) CED-4
C) CED-9
D) the death signal receptor
E) a nuclease

Question 65

The nervous system structures develop from the ectoderm.

Question 66

What are the characteristics of the animal and vegetal poles of the egg?

Question 67

Cell differentiation occurs due to ____.

A) unequal cytoplasmic divisions
B) the removal of different genes in different cell types
C) polarization of the cell
D) the presence of the X and/or Y chromosome in the cell
E) changes in gene expression in different cell types

Question 68

What is the immune function of the placenta in human embryonic development?

Question 69

Maternal blood mixes directly with the embryo's blood in the placenta.

Question 70

Removal of webbing between human fingers is an example of ____.

A) induction
B) apoptosis
C) differentiation
D) meiosis
E) determination

Question 71

Research indicates that ____ defects occur ____ often with multiple births than single births.

A) central nervous system; less
B) heart; more
C) musculoskeletal; more
D) gastrointestinal; less
E) chromosomal; less

Question 72

Evidence that all differentiated cells contain the organism's complete genome is provided by ____.

A) comparing frog and sea urchin development
B) observing that some cells remain totipotent
C) observing that totipotent cells give rise to multipotent cells
D) observing that multipotent cells give rise to pluripotent cells
E) the successful cloning of a sheep, Dolly

Question 73

The process of apoptosis can remove structures, such as mammary tissue in male mammals.

Question 74

Whole-cell movements involve the coordinated activity of ____.

A) microtubules only
B) microfilaments only
C) blastomeres only
D) microtubules and microfilaments
E) microtubules, microfilaments, and blastomeres

Question 75

Experiments on selective adhesion between ectoderm, mesoderm, and endoderm derived from amphibian embryos demonstrated that ____.

A) ectoderm cells have positive affinity for mesoderm cells, but negative affinity for endoderm cells
B) ectoderm cells have negative affinity for mesoderm cells, but positive affinity for endoderm cells
C) mesoderm cells have negative affinity for endoderm and ectoderm cells
D) ectoderm cells have positive affinity for both endoderm and mesoderm cells
E) endoderm cells have positive affinity for both ectoderm and mesoderm cells

Question 76

Scientists have traced the cell lineage of every somatic and germ-line cell in C. elegans and found that the resulting embryo differentiates into an adult hermaphrodite that has exactly _____ cells or an adult male that has _____ cells.

A) 1,031; 959
B) 959; 1,551
C) 959; 1,031
D) 1,551; 959
E) 1,551; 1,031

Question 77

During differentiation, organs develop with different numbers of cells due to ____.

A) cell adhesion molecules that are only present in some tissues
B) cell migration
C) cell determination
D) the variable length of mitotic interphase
E) microtubule rearrangement

Question 78

Cells that undergo apoptosis are essential to the organism into adulthood.

Question 79

Tissues present during organ development that are not found in the fully formed organ are removed by ____.

A) apoptosis only
B) differentiation only
C) induction only
D) apoptosis and differentiation
E) apoptosis, differentiation, and induction

Question 80

The material in the gray crescent of a frog embryo is necessary for normal development.