Deck 51: Animal Reproduction

Question 1

During the human ovarian cycle, ovulation is stimulated by

A) a decrease in FSH secretion.
B) an increase in progesterone secretion.
C) an increase in LH secretion.
D) the presence of semen in the vagina.
E) a decrease in estradiol concentration in the blood.

Answer 1

Luteinizing hormone (LH) causes the eruption of the follicle in the ovary known as ovulation. Near the end of the follicular phase of the menstrual cycle, a spike in gonadotropin-releasing hormone causes a surge in LH. The result of this surge is ovulation.
Therefore, the correct answer is
an increase in LH secretion.

Question 2

During the secretory phase of the menstrual cycle, endometrial glands secrete

A) hormones that increase the likelihood of pregnancy.
B) nutritive substances that sustain an embryo during the first 2 weeks of development.
C) hormones that prevent ovulation.
D) waste products into the lumen of the uterus.
E) both a and c.

Answer 2

During the second half of the menstrual cycle, the uterus prepares to support a pregnancy. In order to do this, the uterus undergoes changes including more endometrial growth and the development of glands. These glands produce food that can sustain the embryo for its first two weeks.
Therefore, the correct answer is
nutritive substances that sustain an embryo during the first two weeks of development.

Question 3

During the _________ stage of labor in mammals, the placenta is expelled from the uterus.

A) first
B) second
C) third
D) It is not expelled; the placenta is reabsorbed.

Answer 3

Delivery of a baby is divided into three stages. The first stage involves the cervix relaxing, dilating, and finally thinning out. Stage two includes the contractions and birth. In Stage three, the uterus continues to contract. Also the blood vessels in the placenta and umbilical cord contract, which causes blood flow to be hindered. Finally, the placenta will be ejected.
Therefore, the correct answer is
third.

Question 4

Define asexual reproduction and give three examples.

Question 5

Distinguish among viviparity, ovoparity, and ovoviviparity, and give examples of animals for each type. Which type characterizes humans What is an advantage of viviparity

Question 6

The development of offspring from unfertilized eggs is

Question 7

Compare and contrast internal fertilization and external fertilization.

Question 8

A principle of biology is that living organisms use energy. What are some of the energy costs associated with sexual reproduction What outweighs those costs and accounts for the observation that most animals reproduce sexually

Question 9

Which is considered an advantage of sexual reproduction

A) necessity to locate a mate
B) increased energy expenditure in producing gametes that may not be used in reproduction
C) increased genetic variation
D) decreased genetic variation
E) both a and b

Question 10

How does the hypothalamus influence vertebrate reproduction

Question 11

Spermatogonia

A) are germ cells.
B) are diploid cells.
C) are male gametes.
D) have flagella.
E) a and b only.

Question 12

Compared with external fertilization, in internal fertilization,

A) male gametes have a higher chance to come into close proximity to female gametes.
B) gametes are less protected against predation or other harmful environmental factors.
C) there is a decreased likelihood of desiccation of gametes.
D) gametes come into contact only outside the mother's reproductive tract.
E) Both b and c are true of internal fertilization.

Question 13

Which of the following is an example of ovoviviparity

A) Honeybees lay soft eggs within the hive.
B) Sharks hatch from shell-covered fertilized eggs within the female's body.
C) Birds hatch from shell-covered fertilized eggs laid within a nest.
D) Fetal mammals obtain nourishment from the mother through a placenta.
E) Amphibian eggs are released into the water column, where they may be fertilized.

Question 14

The fructose in semen is secreted by the

Question 15

A major function of FSH is to

A) stimulate the development of the gonads during early development.
B) stimulate spermatogenesis in males and oocyte maturation in females.
C) increase the secretion of testosterone by the testes.
D) regulate the secretion of the bulbourethral glands.
E) inhibit the activity of Sertoli cells in the testes.