Question 1

Which of the following best explains why sexual reproduction is considered an evolutionary enigma, despite its prevalence among eukaryotic species?

Accepted Answer

Sexual females have half as many daughters as asexual females, resulting in the 'twofold cost' of sex.

Question 2

A sea anemone splits into two individuals of approximately equal size. Which mechanism of asexual reproduction is this an example of?

Accepted Answer

Fission

Question 3

Which reproductive strategy is most advantageous in a stable, favorable environment, and why?

Accepted Answer

Asexual reproduction, because it allows rapid population growth without the need for a mate.

Question 4

In some species of whiptail lizards, reproduction is exclusively asexual, yet courtship and mating behaviors still occur. What is the biological significance of this behavior?

Accepted Answer

It stimulates ovulation in the absence of males.

Question 5

Which of the following statements about hermaphroditism is correct?

Accepted Answer

Hermaphrodites have both male and female reproductive systems and can sometimes self-fertilize.

Question 6

Why is a moist habitat almost always required for external fertilization?

Accepted Answer

To prevent gametes from drying out and to allow sperm to swim to eggs.

Question 7

Which accessory gland in the human male reproductive system secretes a clear mucus before ejaculation that neutralizes acidic urine in the urethra?

Accepted Answer

Bulbourethral glands

Question 8

During spermatogenesis, how many mature gametes are produced from one precursor cell after meiosis?

Accepted Answer

$$4$$

Question 9

Which hormone is secreted by the hypothalamus and directs the release of FSH and LH from the anterior pituitary?

Accepted Answer

Gonadotropin-releasing hormone (GnRH)

Question 10

A patient has abnormally low levels of FSH and LH. Which feedback mechanism is most likely responsible for this condition?

Accepted Answer

Negative feedback from testosterone and inhibin

Question 11

Which event marks the beginning of the ovarian cycle in human females?

Accepted Answer

Release of GnRH from the hypothalamus

Question 12

What is the primary function of the endometrium during the menstrual cycle?

Accepted Answer

To nourish and support a developing embryo

Question 13

Which of the following best describes the difference between menstrual and estrous cycles?

Accepted Answer

Menstrual cycles involve shedding of the endometrium, while estrous cycles involve reabsorption.

Question 14

During fertilization in sea urchins, what triggers the cortical reaction, and what is its biological purpose?

Accepted Answer

Entry of sperm triggers a release of $$Ca^{2+}$$, which activates the cortical reaction to prevent polyspermy.

Question 15

Which germ layer forms the digestive tract during gastrulation?

Accepted Answer

Endoderm

Question 16

A woman gives birth to identical twins. Which of the following best explains how this occurs?

Accepted Answer

One embryo splits during the first month of development, resulting in two genetically identical individuals.

Question 17

Which hormone stimulates the mammary glands to produce milk in response to suckling?

Accepted Answer

Prolactin

Question 18

Which contraceptive method has a pregnancy rate of less than 1% and works by interfering with fertilization and implantation?

Accepted Answer

Intrauterine devices (IUDs)

Question 19

A couple is unable to conceive due to low sperm count. Which assisted reproductive technology could directly address this issue?

Accepted Answer

In vitro fertilization (IVF) with direct injection of sperm nucleus into an oocyte

Reproduction and Development: Study Notes (Campbell Biology in Focus, Chapter 36)

Guida di studio - Domande di pratica

Study guide - Flashcard