dizygotic dz twins run in families

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Maternity HESI Test Bank

1. Do dizygotic (DZ) twins run in families?

A. Yes
B. No
C. Rarely
D. Never

Correct answer: A

Rationale: Yes, dizygotic (DZ) twins can run in families. This is due to genetic factors that influence hyperovulation, where a woman releases multiple eggs during her menstrual cycle. This genetic predisposition can be passed down through generations, increasing the likelihood of having dizygotic twins. Choices B, C, and D are incorrect because the statement that dizygotic twins run in families is true, as supported by scientific evidence. It is important to note that while the genetic predisposition for dizygotic twins can run in families, it does not guarantee that every generation will have twins, as other factors also play a role in twin pregnancies.

2. Are sperm much larger than ova?

A. TRUE
B. FALSE
C. Sometimes
D. Always

Correct answer: B

Rationale: The correct answer is B: FALSE. Ova, also known as eggs, are actually the largest cells in the human body, while sperm are significantly smaller. This size difference is due to the different functions of the two gametes. Sperm are specialized for motility to reach and fertilize the egg, while ova contain nutrients and cellular machinery needed for fertilization and early embryonic development. Choices A, C, and D are incorrect because sperm are not larger than ova; they are much smaller in size.

3. Which of the following is most likely to develop sickle cell anemia?

A. European American
B. Native American
C. African American
D. Asian American

Correct answer: C

Rationale: Sickle cell anemia is most commonly found in individuals of African American descent. This is because sickle cell trait provides some protection against malaria, and historically, regions where malaria is or was prevalent have higher rates of sickle cell anemia. Therefore, individuals with African ancestry are at a higher risk of developing sickle cell anemia compared to other populations. Choices A, B, and D are less likely to develop sickle cell anemia due to lower genetic prevalence in their respective populations.

4. _____ is a type of estrogen, prescribed in the 1940s and 1950s to pregnant women, that is said to have caused testicular, vaginal, and cervical cancer in some offspring.

A. Androsterone
B. Adiponectin
C. Progestin
D. Diethylstilbestrol

Correct answer: D

Rationale: Diethylstilbestrol (DES) is a synthetic estrogen that was prescribed to pregnant women in the 1940s and 1950s to prevent miscarriages. However, it was later discovered that DES exposure in utero could lead to health issues in offspring, including an increased risk of testicular, vaginal, and cervical cancer. Choice A, Androsterone, is a steroid hormone produced in small amounts in humans and unlikely to be associated with the adverse effects described. Choice B, Adiponectin, is a protein hormone that plays a role in regulating glucose levels and fatty acid breakdown, not related to the adverse effects mentioned. Choice C, Progestin, is a synthetic form of progesterone used in birth control and hormone therapy, not linked to the specific health concerns associated with DES exposure.

5. Twenty-year-old Jack is extremely tall and has very thick facial hair. Most of his male secondary sex characteristics are also more pronounced than men of his age. In this scenario, Jack is most likely:

A. an XYY male.
B. diagnosed with Klinefelter syndrome.
C. an XXY male.
D. diagnosed with Down syndrome.

Correct answer: A

Rationale: The correct answer is A: an XYY male. Individuals with XYY syndrome often exhibit increased height and more pronounced secondary male characteristics, such as thick facial hair. Choice B, Klinefelter syndrome (XXY), typically presents with less prominent male secondary sex characteristics due to the presence of an extra X chromosome. Choice C, XXY male, refers to Klinefelter syndrome, which does not align with the description of Jack having more pronounced male secondary sex characteristics. Choice D, Down syndrome, is caused by a trisomy of chromosome 21 and is not associated with the physical characteristics described in the scenario.