Human Biology

Sylvia S. Mader, Michael Windelspecht

Chapter 18

Development and Aging - all with Video Answers

Educators

Chapter Questions

Problem 1

Only one sperm enters an egg because
a. sperm have an acrosome.
b. the corona radiata gets larger.
c. changes occur in the zona pellucida.
d. the cytoplasm hardens.
e. All of these are correct.

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 2

The fusion of a sperm and an egg cell initally produces which of the following?
a. blastocyst
b. zygote
c. morula
d. gamete
e. stem cell

Joanna Quigley

Numerade Educator

Problem 3

Label each of the indicated stages of pre-embryonic development.

Joanna Quigley

Numerade Educator

Problem 4

Which of these is mismatched?
a. chorion-sense perception
b. yolk sac-first site of blood cell formation
c. allantois - umbilical blood vessels
d. amnion- contains fluid that protects embryo

Joanna Quigley

Numerade Educator

Problem 5

Which primary germ layer is not correctly matched to an organ system or organ that develops from it?
a. ectoderm-nervous system
b. endoderm-lining of the digestive tract
c. mesoderm- skeletal system
d. endoderm-cardiovascular system

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 6

Which process involves the shaping of the embryo and cell migration?
a. cleavage
b. differentiation
c. growth
d. morphogenesis

Prashant Bana

Numerade Educator

Problem 7

Which association is not correct?
a. third and fourth months - fetal heart has formed, but it does not beat
b. fifth through seventh months-mother feels movement
c. eighth through ninth months- -usually head is now pointed toward the cervix
d. All of these are correct.

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 8

Which of these structures is not a circulatory feature unique to the fetus?
a. arterial duct
b. oval opening
c. umbilical vein
d. pulmonary trunk

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 9

Which of these statements is correct?
a. Fetal circulation, like adult circulation, takes blood equally to a pulmonary circuit and a systemic circuit.
b. Fetal circulation shunts blood away from the lungs but makes full use of the systemic circuit.
c. Fetal circulation includes an exchange of substances between fetal blood and maternal blood at the placenta.
d. Unlike adult circulation, fetal blood always carries oxygen-rich blood and therefore has no need for the pulmonary circuit.
e. Both b and c are correct.

Joanna Quigley

Numerade Educator

Problem 10

Which of the following does not occur if the $S R Y$ gene is present in the fetus?
a. The Wolffian duct becomes the male genital ducts.
b. The Müllerian ducts disappear.
c. The testes develop.
d. The urethra and genital tracts remain separate.
e. None of these are correct.

Joanna Quigley

Numerade Educator

Problem 11

Which of the following hormones is not matched correctly to its effect on the mother?
a. peptide hormones- increased resistance to insulin
b. progesterone- reduced chances of the mother having an immune reaction to the fetus
c. estrogen-increased uterine blood flow
d. progesterone- relaxation of smooth muscle and decrease in blood pressure
e. All of these are correct.

Joanna Quigley

Numerade Educator

Problem 12

Which of the following is increased in the mother during pregnancy?
a. metabolic rate
b. blood volume
c. cardiac output
d. All of these are correct.

Joanna Quigley

Numerade Educator

Problem 13

After each cell division, these chromosomal structures shorten, thus regulating the life span of a cell.
a. mitochondria
b. free radicals
c. telomeres
d. plasma membranes

Joanna Quigley

Numerade Educator

Problem 14

Which of the following is associated with the aging process?
a. reduction in the production of sex hormones, such as testosterone
b. increased chances of dehydration
c. decrease in bone density
d. decrease in the ability of the senses to detect stimuli
e. All of these are correct.

Joanna Quigley

Numerade Educator