Nursing Elites

1. 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.

2. After mitosis, the genetic code is identical in new cells unless _________ occur through radiation or other environmental influences.

• A. reductions
• B. expulsions
• C. conceptions
• D. mutations

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.

3. Which of the following is a fatal genetic neurologic disorder whose onset is in middle age?

• A. Tay-Sachs disease
• B. Duchenne muscular dystrophy
• C. Hemophilia
• D. Huntington’s disease

Correct answer: D

Rationale: Huntington's disease is a fatal genetic neurologic disorder characterized by progressive nerve cell degeneration in the brain. It typically manifests in middle age with symptoms such as involuntary movements, cognitive decline, and psychiatric disturbances. Tay-Sachs disease (Choice A) is a genetic disorder that primarily affects the nervous system in early childhood, not middle age. Duchenne muscular dystrophy (Choice B) is a genetic disorder that primarily affects muscle function and usually presents in early childhood. Hemophilia (Choice C) is a genetic disorder related to blood clotting, and its onset is not typically in middle age.

4. When do mothers usually feel the first fetal movements during pregnancy?

• A. At 18-20 weeks
• B. During the first month
• C. Rarely
• D. Never

Correct answer: A

Rationale: Mothers usually feel the first fetal movements, known as 'quickening,' around the 18th to 20th week of pregnancy. Feeling fetal movements during the first month is unlikely and uncommon. Therefore, option B is incorrect. Options C and D are also incorrect as mothers typically do feel fetal movements during pregnancy, just not during the first month.

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.

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