Biology

Sylvia S. Mader, Michael Windelspecht

Chapter 42

Animal Development - all with Video Answers

Educators

Chapter Questions

Problem 1

Only one sperm enters and fertilizes a human ovum because
a. sperm have an acrosome.
b. the corona radiata gets larger.
c. the zona pellucida lifts up.
d. a fertilization membrane forms.
e. All of these are correct.

Grant Castaneda

Grant Castaneda

Numerade Educator

Problem 2

Which of these stages is the first one out of sequence?
a. cleavage
b. blastula
c. morula
d. gastrula
e. neurula

Grant Castaneda

Grant Castaneda

Numerade Educator

Problem 3

Which of these stages is mismatched?
a. cleavage—cell division
b. blastula—gut formation
c. gastrula—three germ layers
d. neurula—nervous system
e. Both b and c are mismatched.

Grant Castaneda

Grant Castaneda

Numerade Educator

Problem 4

Developmental changes
a. require growth, differentiation, and morphogenesis.
b. stop occurring when one is grown.
c. are dependent on a parceling out of genes into daughter cells.
d. are dependent on activation of master genes in an orderly sequence.
e. Both a and d are correct.

Grant Castaneda

Grant Castaneda

Numerade Educator

Problem 5

The ability of one embryonic tissue to influence the growth and development of another tissue is termed
a. morphogenesis.
b. pattern formation.
c. apoptosis.
d. cellular differentiation.
e. induction.

Grant Castaneda

Grant Castaneda

Numerade Educator

Problem 6

Match the statement with the terms in the key.
Key:
a. apoptosis
b. homeotic genes
c. fate maps
d. morphogen gradients
e. segment-polarity genes

Have been developed that show the destiny of each cell that arises through cell division during the development of C. elegans

Grant Castaneda

Grant Castaneda

Numerade Educator

Problem 7

Match the statement with the terms in the key.
Key:
a. apoptosis
b. homeotic genes
c. fate maps
d. morphogen gradients
e. segment-polarity genes

Occurs when a cell-death cascade is activated

Grant Castaneda

Grant Castaneda

Numerade Educator

Problem 8

Match the statement with the terms in the key.
Key:
a. apoptosis
b. homeotic genes
c. fate maps
d. morphogen gradients
e. segment-polarity genes

Can have a range of effects, depending on its concentration in a particular portion of the embryo

Grant Castaneda

Grant Castaneda

Numerade Educator

Problem 9

Match the statement with the terms in the key.
Key:
a. apoptosis
b. homeotic genes
c. fate maps
d. morphogen gradients
e. segment-polarity genes

Genes that control pattern formation, the organization of differentiated cells into specific three-dimensional structures.

Grant Castaneda

Grant Castaneda

Numerade Educator

Problem 10

Label this diagram illustrating the placement of the extra embryonic membranes, and give a function for each membrane in humans.

Grant Castaneda

Grant Castaneda

Numerade Educator

Problem 11

Which developmental stage is mismatched?
a. second week—implantation
b. third week—heart development begins
c. fourth and fifth week—limb buds appear
d. sixth through eighth week—all organ systems present
e. None of these stages are mismatched.

Grant Castaneda

Grant Castaneda

Numerade Educator

Problem 12

Near the time of parturition, which hormone stimulates the fetal adrenal cortex to release androgens?
a. fetal ACTH
b. fetal estrogen
c. maternal ACTH
d. maternal estrogen

Grant Castaneda

Grant Castaneda

Numerade Educator

Problem 13

Which of the following is not an explanation for why the skin of older people tends to become wrinkled?
a. increased subcutaneous fat deposition
b. increased cross-linking of collagen fibers
c. decreased sebaceous gland activity
d. decreased number of elastic fibers

Grant Castaneda

Grant Castaneda

Numerade Educator

Problem 14

The onset of menopause is mainly due to
a. a lack of ovarian follicles that are able to ovulate.
b. an involution of the uterus that begins around age 45.
c. an unresponsiveness of the ovaries to FSH and LH from the pituitary.
d. an increased production of male hormones

Grant Castaneda

Grant Castaneda

Numerade Educator

Problem 15

Possible causes of the cellular damage that can accumulate and contribute to aging include
a. free radicals.
b. spontaneous DNA mutations.
c. cross-linked proteins.
d. UV radiation.
e. All of these are correct.

Grant Castaneda

Grant Castaneda

Numerade Educator