Nursing Elites

1. Which of the following statements is true of Down’s syndrome?

• A. Down’s syndrome is usually caused by an extra copy of chromosome 21 in an individual.
• B. The symptoms of Down’s syndrome are similar to those of sickle-cell anemia.
• C. Down’s syndrome is caused by a sexually transmitted infection (STI) during conception.
• D. The probability of having a child with Down’s syndrome increases with the age of the parents.

Correct answer: D

Rationale: The correct answer is D. The likelihood of having a child with Down’s syndrome increases as the age of the parents increases, particularly the mother's age. Choice A is incorrect because Down’s syndrome is caused by an extra copy of chromosome 21, not a defect in the sex chromosomes. Choice B is incorrect as the symptoms of Down’s syndrome and sickle-cell anemia are different. Choice C is also incorrect as Down’s syndrome is not caused by a sexually transmitted infection during conception.

2. 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.

3. Before meiosis, a sperm cell:

• A. contains 46 chromosomes.
• B. contains two X chromosomes.
• C. is significantly larger than an egg cell.
• D. contains both an X and a Y chromosome.

Correct answer: A

Rationale: Before meiosis, a sperm cell contains 46 chromosomes. This is because sperm cells, like other somatic cells, have a diploid number of chromosomes. During meiosis, the number of chromosomes is halved to 23 to combine with an egg cell during fertilization. Choice B is incorrect because a sperm cell carries either an X or a Y chromosome, not both (Choice D). Choice C is incorrect as sperm cells are generally smaller than egg cells, which is an adaptation that aids in motility and penetration of the egg during fertilization.

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. Humans begin life as a single cell that divides repeatedly. This cell is known as a(n):

• A. zygote.
• B. gonadotrope.
• C. embryo.
• D. chromaffin.

Correct answer: A

Rationale: A zygote is the correct answer. It is the initial cell formed when a sperm cell fertilizes an egg cell, marking the beginning of human development. Choice B, gonadotrope, is incorrect as it refers to a type of hormone-secreting cell in the pituitary gland. Choice C, embryo, is incorrect as it is the stage of development after the zygote has implanted into the uterine wall and undergone initial cell divisions. Choice D, chromaffin, is incorrect as it refers to cells found in the adrenal medulla that produce and store catecholamines.

Similar Questions