Question 1

A k-selected species

Accepted Answer

K-selected species are characterized by high parental involvement, which helps ensure the survival of fewer offspring. They invest more in fewer offspring, unlike r-selected species that produce many offspring with minimal parental care.

Question 2

Which of the following is ovoviviparous?

Accepted Answer

E

Question 3

Which of the following is not a secondary sexual characteristic?

Accepted Answer

Secondary sexual characteristics are traits that appear at sexual maturity and distinguish the two sexes of a species, but are not directly involved in reproduction. Sensory sensilla are not secondary sexual characteristics; they are sensory organs found in insects and other animals, involved in detecting environmental cues rather than in sexual differentiation or attraction.

Question 4

Birds derive seminal fluid from the

Accepted Answer

Seminal fluid is derived from the seminiferous tubules and vasa efferentia. The seminiferous tubules produce sperm, while the vasa efferentia transport sperm from the seminiferous tubules to the epididymis.

Question 5

The copulatory plug

Accepted Answer

The copulatory plug is a feature observed in certain insects and other animals, which serves to prevent semen from escaping the female reproductive tract after mating. This ensures that the sperm has a better chance of fertilizing the female's eggs, thereby increasing reproductive success.

Question 6

Which organ stores sperm in insect reproductive systems?

Accepted Answer

The spermatheca is the organ in female insects that stores sperm after mating. This allows the female to fertilize eggs long after mating has occurred.

Question 7

Juvenille hormone (JH)

Accepted Answer

Juvenile hormone (JH) is involved in both oogenesis and vitellogenesis, playing a crucial role in the reproductive processes of insects by regulating the development and maturation of eggs.

Question 8

In mammals, gonadal differentiation is determined by

Accepted Answer

Gonadal differentiation in mammals is primarily determined by the presence or absence of the Y chromosome. The SRY gene on the Y chromosome initiates the development of the testes, leading to male gonadal differentiation.

Question 9

What effect does the presence of Mullerian inhibiting substance have on fetal development?

Accepted Answer

Mullerian inhibiting substance, also known as anti-Mullerian hormone (AMH), is produced by the Sertoli cells of the testes in male embryos. Its primary role is to cause the regression or degeneration of the Mullerian ducts, which in the absence of this substance would develop into female reproductive organs such as the uterus, fallopian tubes, and the upper part of the vagina.

Question 10

Before birth testosterone is responsible for

Accepted Answer

Testosterone is responsible for promoting the descent of testes before birth.

Question 11

Testosterone

Accepted Answer

Testosterone stimulates bone growth, contributes to the closure of growth plates (thereby eventually stopping bone growth), and has been shown to have an effect on aggression in males.

Question 12

The acrosome of the mammalian spermatozoa is

Accepted Answer

The acrosome of mammalian spermatozoa is indeed an enzyme-containing vesicle that plays a crucial role in fertilization by lysing the outer covering of the egg, facilitating sperm entry. It is derived from the Golgi apparatus during the development of the sperm cell, making all the given options correct.

Question 13

Sertoli cells

Accepted Answer

Sertoli cells are specialized epithelial cells within the seminiferous tubules of the testis. They extend from the basal lamina to the lumen of the tubule, creating a barrier and structural support for developing sperm cells. They are connected by tight junctions, which contribute to the blood-testis barrier, and form gap junctions with germ cells to facilitate nutrient and signal exchange. Therefore, all of the statements provided are correct descriptions of Sertoli cells.

Question 14

Which of the following secrete an alkaline fluid that increases sperm viability?

Accepted Answer

The prostate gland secretes an alkaline fluid that increases sperm viability.

Question 15

Primary oocytes are

Accepted Answer

Primary oocytes are diploid, meaning they contain two sets of chromosomes, one from each parent. They are formed during fetal development in females and remain in a suspended state of meiosis until puberty.

Question 16

The first meiotic division of the primary oocyte is completed

Accepted Answer

The first meiotic division of the primary oocyte is completed before ovulation, resulting in the formation of a secondary oocyte and a polar body.

Question 17

Which of the following constitutes the primordial follicle?

Accepted Answer

The primordial follicle consists of a primary oocyte surrounded by a single layer of granulosa cells.

Question 18

Which of the following hormones is responsible for causing the differentiation of follicular cells and the formation of a mature follicle?

Accepted Answer

The answer of Which of the following hormones is responsible...

Question 19

The LH surge associated with ovulation is triggered by

Accepted Answer

The LH surge that triggers ovulation is primarily caused by a positive feedback loop with estrogen. As estrogen levels rise, they signal the anterior pituitary gland to release luteinizing hormone (LH), which in turn triggers ovulation.

Question 20

Which of the following hormones passes the blood brain barrier and is converted to estradiol?

Accepted Answer

Testosterone can cross the blood-brain barrier and is converted into estradiol in the brain by the enzyme aromatase.

Quiz 16: Reproductive Systems