Nursing Elites

1. The _____ is the inner layer of the embryo from which the lungs and digestive system develop.

• A. neural tube
• B. mesoderm
• C. endoderm
• D. umbilical cord

Correct answer: C

Rationale: The endoderm is the correct answer. It is the innermost layer of the embryo that gives rise to organs such as the lungs, digestive system, liver, and pancreas. The neural tube (Choice A) forms the brain and spinal cord, not the lungs or digestive system. Mesoderm (Choice B) develops into structures like muscles, bones, and circulatory system, not the lungs or digestive system. The umbilical cord (Choice D) serves as a connection between the embryo and the placenta, providing nutrients and oxygen, but it is not the layer from which lungs and digestive system develop.

2. 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.

3. Thalidomide was marketed in the 1960s as a treatment for:

• A. insomnia and nausea.
• B. infertility and impotence.
• C. Down syndrome.
• D. Turner syndrome.

Correct answer: A

Rationale: Thalidomide was initially marketed as a treatment for insomnia and nausea, particularly in pregnant women. However, it was later found to cause severe birth defects, leading to significant consequences. Choice B, infertility and impotence, is incorrect as thalidomide was not marketed for these conditions. Choices C and D, Down syndrome and Turner syndrome, are genetic conditions and not conditions for which thalidomide was intended as a treatment.

4. As women reach the end of their childbearing years, does ovulation become more regular?

• A. TRUE
• B. FALSE
• C. Rarely
• D. Always

Correct answer: B

Rationale: The correct answer is B: FALSE. As women age and reach the end of their childbearing years, ovulation becomes less regular due to hormonal changes associated with menopause. This can result in irregular ovulation patterns or even the cessation of ovulation entirely. Choice A is incorrect because ovulation does not become more regular with age. Choices C and D are also incorrect as they do not accurately reflect the changes in ovulation patterns that occur as women approach the end of their childbearing years.

5. When both of the alleles for a trait, such as hair color, are the same, the person is said to be _____ for that trait.

• A. monozygous
• B. dizygous
• C. homozygous
• D. hemizygous

Correct answer: C

Rationale: A person is homozygous for a trait when they have two identical alleles for that trait. In this case, both alleles are the same, indicating a homozygous genotype. Choice A, 'monozygous,' is incorrect as it refers to identical twins originating from a single fertilized egg. Choice B, 'dizygous,' is also incorrect as it refers to fraternal twins or individuals that develop from two separate fertilized eggs. Choice D, 'hemizygous,' is incorrect because it describes a genetic condition where only one allele is present in a diploid organism, typically related to genes on the sex chromosomes.

Similar Questions