During which of the following periods does the development of arms and legs occur in a pregnancy?

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: 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.

Correct Answer: A

Rationale: Monozygotic (MZ) twins share 100% of their genes because they originate from the same fertilized egg that splits into two, resulting in identical genetic material for both twins. Choice B (75%) is incorrect as it implies a partial genetic similarity, which is not the case for MZ twins. Choice C (50%) is incorrect as it suggests half of the genes are shared, which is applicable to dizygotic (DZ) twins, not MZ. Choice D (25%) is incorrect as it indicates minimal genetic sharing, which is not true for MZ twins.

Correct Answer: D

Rationale: The correct answer is D. False labor contractions, also known as Braxton Hicks contractions, are typically irregular and do not lead to cervical dilation or effacement. They are often described as sporadic and temporary, becoming temporarily regular. Choices A, B, and C are incorrect because false labor contractions do not intensify with activity, do not cause cervical changes like dilation and effacement, and are not associated with the presence of a bloody show.

Correct Answer: A

Rationale: When assessing a preterm newborn at 32 weeks of gestation, healthcare providers should expect minimal arm recoil. This finding is common in preterm infants due to lower muscle tone. Choice B, a popliteal angle of less than 90°, is incorrect for this age group. Creases over the entire sole (Choice C) typically develop at term age, not at 32 weeks of gestation. Sparse lanugo (Choice D) is a normal finding in preterm infants but is not specific to those at 32 weeks of gestation.