NCLEX : General Biology

Study concepts, example questions & explanations for NCLEX

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Example Questions

Example Question #71 : General Biology

Which of the following is not a function of progesterone during pregnancy?

Possible Answers:

Breast maturation in preparation for lactation

Increases the contractility of the uterus

Decreases maternal immune response to the fetus

Inhibits lactation during pregnancy

Correct answer:

Breast maturation in preparation for lactation

Explanation:

Progesterone serves many functions in pregnancy. It prepares the endometrial lining for implantation of the embryo, it increases the contractility of the uterus, it inhibits lactation during pregnancy, and it is thought to reduce maternal immune response to the developing fetus. Breast enlargement and maturation in preparation for lactation is facilitated by estrogen, rather than progesterone.

Example Question #72 : General Biology

Which of the following proteins initiates male sexual development in utero?

Possible Answers:

Testosterone-sensitizing protein

Masculinization factor

Male-determining protein

Testis-determining factor 

Correct answer:

Testis-determining factor 

Explanation:

Testis-determining factor, also known as sex-determining region Y (SRY) protein, is a sex-determining gene found exclusively on the Y-chromosome in humans. It's transcription triggers the development of male sexual characteristics in the developing fetus.

Example Question #73 : General Biology

The Sertoli cells of the testes secrete all of the following except __________.

Possible Answers:

Androgen binding protein

Estradiol 

Anti-Müllerian hormone

All of these are secreted by the Sertoli cells

Correct answer:

All of these are secreted by the Sertoli cells

Explanation:

The Sertoli cells of the testes are responsible for the secretion of many substances, including anti-Müllerian hormone, androgen binding protein, glial cell line-derived neurotrophic factor, and estradiol.

Example Question #74 : General Biology

Which of the following is the term used to describe the post-ejaculatory transformation of sperm via enzymes in the uterus and seminal fluid?

Possible Answers:

Decapitation

Spermatazoal maturation

Penultimation

Capacitation

Correct answer:

Capacitation

Explanation:

The process by which post-ejaculatory sperm is rendered fully mature and capable of fertilization of an ovum is called capacitation. This is where enzymes within the uterus are able to partially degrade the acrosome, the cap surrounding the head of the spermatazoa, allowing it to bind with and eventually penetrate the zona pellucida of the egg.

Example Question #75 : General Biology

Which of the following minerals stabilizes sperm cell chromatin?

Possible Answers:

Magnesium

Manganese

Zinc

Copper

Correct answer:

Zinc

Explanation:

The stability of sperm cell chromatin is dependent on zinc. Zinc deficiency can cause sperm to be fragile, which in turn lowers sperm count and decreases male fertility.

Example Question #75 : General Biology

The average ejaculate contains how many sperm?

Possible Answers:

50 - 100 million

100 - 400 million

500 - 800 million

700-900 million

Correct answer:

100 - 400 million

Explanation:

Male ejaculate can contain any where from 40 million to 1 billion sperm, though the average ejaculate contains between 100 and 400 million. 

Example Question #76 : General Biology

What is the main source of energy for sperm cells in ejaculate? 

Possible Answers:

Starch 

Fructose

Sucrose

Galactose

Correct answer:

Fructose

Explanation:

The primary energy source of spermatozoa is fructose, produced by the seminal vesicle along with multiple amino acids, vitamin C, enzimes, and flavin. 

Example Question #77 : General Biology

Where are mature spermatozoa stored before ejaculation?

Possible Answers:

In the epididymis 

In the vas deferens

In the seminiferous tubules

In the seminal vesicles

Correct answer:

In the epididymis 

Explanation:

Fully formed spermatozoa from the seminal vesicles are transported to the epididymis, where they are stored for 2-3 months. During ejaculation, stored sperm are moved from the lower epididymis via peristaltic action of the muscle layers of the vas deferens, mixed with various fluids to form semen.  

Example Question #78 : General Biology

Which of the following structures produces the fluids that combine with sperm to form semen?

Possible Answers:

All of these are correct

The seminal vesicles

The bulbourethral gland

The prostate

Correct answer:

All of these are correct

Explanation:

Seminal fluid is formed by several glands: the prostate contributes proteolytic enzymes, citric acid, acid phosphatase, zinc, fibrinolysin, and prostate specific antigen. The seminal vesicles contribute various flavins, fructose, and amino acids. The bulbourethral glands secrete a mucus that allows the semen to travel rapidly through the urethra, potentially aiding its route toward the cervix.  

Example Question #71 : General Biology

What is the reproductive function of the prostate?

Possible Answers:

Production of fructose

Lubrication of the urethra

Aids in sperm production

Alkalinization of the semen

Correct answer:

Alkalinization of the semen

Explanation:

The prostate, a fleshy endocrine gland inferior to the outlet of the male bladder, secretes a slightly alkaline milky fluid that makes up one third of the volume of semen. This alkalinity helps neutralize the acid environment of the vagina, increasing the likelihood of conception. Lubrication of the urethra is provided by the bulbourethral gland, while fructose is produced within the seminal vesicles. The prostate does not take part in sperm production. 

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