Question 1

Which of the following statements best describes the difference between asexual and sexual reproduction in animals?

Accepted Answer

Asexual reproduction produces genetically identical offspring, while sexual reproduction produces genetically different offspring.

Question 2

Which mechanism of asexual reproduction involves the female producing offspring without fertilization from a male, and the offspring are genetically identical to the mother?

Accepted Answer

Parthenogenesis

Question 3

During spermatogenesis in mammals, what is the ploidy of the primary spermatocyte before meiosis begins?

Accepted Answer

2n

Question 4

Which structure in the mammalian sperm contains enzymes that help the sperm penetrate the egg?

Accepted Answer

Acrosome

Question 5

In oogenesis, why does the primary oocyte undergo unequal meiotic divisions?

Accepted Answer

To ensure that one large egg receives most of the cytoplasm and nutrients, while the polar bodies are much smaller

Question 6

Which of the following best describes external fertilization?

Accepted Answer

Gametes are released into the environment and fertilization occurs outside the body.

Question 7

Which hormone is primarily responsible for triggering puberty in human males?

Accepted Answer

Testosterone

Question 8

What is the function of the hormone human chorionic gonadotropin (hCG) during early pregnancy?

Accepted Answer

It prevents the corpus luteum from disintegrating, allowing continued secretion of progesterone.

Question 9

Which mammalian lineage is characterized by offspring developing externally in a pouch, with nutrition supplied by the mother?

Accepted Answer

Marsupials

Question 10

During the menstrual cycle, which hormone is produced in the ovary and is responsible for maintaining the uterine lining during the luteal phase?

Accepted Answer

Progesterone

Question 11

Which of the following equations correctly represents the formation of a diploid zygote during fertilization?

Accepted Answer

$$n + n = 2n$$

Question 12

Which hormone is released from the hypothalamus and initiates puberty by stimulating the anterior pituitary to release LH and FSH?

Accepted Answer

GnRH

Question 13

Why do hormone-based birth control methods prevent ovulation?

Accepted Answer

They suppress the release of GnRH, LH, and FSH through negative feedback inhibition.

Question 14

Which of the following best explains why the fetus’s blood has a higher affinity for oxygen than the mother’s blood?

Accepted Answer

Fetal hemoglobin binds oxygen more strongly, ensuring efficient transfer from maternal blood.

Question 15

Which hormone is important in stimulating smooth-muscle cells in the uterine wall to begin labor during human birth?

Accepted Answer

Oxytocin

Question 16

Which of the following is a real-world consequence of toxic chemicals transferring from mother to fetus during pregnancy?

Accepted Answer

Fetal alcohol syndrome, which includes hyperactivity, severe learning disabilities, and depression.

Question 17

Which of the following best describes the role of the placenta during pregnancy?

Accepted Answer

It is the primary source of nutrition for the fetus and secretes hormones to prevent ovulation.

Question 18

Which of the following is a plausible explanation for the earlier onset of puberty in girls in the United States compared to the 18th and 19th centuries?

Accepted Answer

Higher fat stores in girls lead to increased leptin production, which may trigger GnRH release and earlier puberty.

Question 19

Which of the following best describes the process of copulation in internal fertilization?

Accepted Answer

Males deposit sperm directly into the female reproductive tract with the aid of a copulatory organ.

Question 20

During the first trimester of human pregnancy, which three major embryonic tissues form and differentiate into organs and systems?

Accepted Answer

Ectoderm, endoderm, and mesoderm

Animal Reproduction and Development: Mechanisms, Structures, and Hormonal Regulation

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