Before meiosis, a sperm cell:

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.

Correct Answer: B

Rationale: Misoprostol can be used for induction in clients with gestational diabetes mellitus. Choice A, a client with active genital herpes, is not a candidate for misoprostol induction due to the risk of viral shedding and transmission. Choice C, a client with a previous uterine incision, may be at risk for uterine rupture with misoprostol use. Choice D, a client with placenta previa, is not an appropriate candidate for misoprostol induction due to the risk of increased bleeding associated with the condition.

Correct Answer: C

Rationale: The correct answer is C. The development of arms and legs occurs during the critical period of the fourth to eighth weeks of pregnancy. This timeframe is crucial for the formation of limbs and other key body parts. Choices A, B, and D are incorrect because the development of the lungs, heart, and stomach respectively occurs at different stages of fetal development and is not primarily associated with the fourth to eighth weeks of pregnancy.

Correct Answer: A

Rationale: Rubella, also known as German measles, is a viral infection that can lead to severe birth defects when contracted by a mother during pregnancy. Rubella is the correct answer because it is specifically associated with causing birth defects such as deafness, intellectual disabilities, blindness, and heart disease in the embryo. Syphilis (Choice B) can be passed from mother to fetus but does not cause the mentioned birth defects associated with Rubella. Cystic fibrosis (Choice C) and Phenylketonuria (Choice D) are genetic conditions and not infections transmitted from mother to fetus, making them incorrect choices in this context.

Correct Answer: D

Rationale: After mitosis, the genetic code is typically preserved and remains identical in the new cells. However, mutations can occur due to radiation or environmental influences, leading to changes in the DNA sequence and potentially altering the genetic code. Therefore, the correct answer is 'mutations.' Choices A, B, and C are incorrect because reductions, expulsions, and conceptions do not accurately describe the changes in the genetic code that can result from external factors. Mutations are the only option that reflects the alteration in the genetic code caused by external influences, making it the correct choice in this context.