Nursing Elites

1. What causes cystic fibrosis?

• A. Sex-linked abnormality.
• B. Abnormality in the 21st pair of chromosomes.
• C. Recessive gene.
• D. Single segment found only on the Y chromosome.

Correct answer: C

Rationale: Cystic fibrosis is a genetic disorder caused by inheriting two copies of a recessive gene, one from each parent. This means that both parents must carry at least one copy of the faulty gene for a child to inherit the condition. Choice A is incorrect because cystic fibrosis is not linked to the sex chromosomes. Choice B is incorrect as cystic fibrosis is not caused by an abnormality in the 21st pair of chromosomes but by a specific gene mutation. Choice D is also incorrect as cystic fibrosis is not related to the Y chromosome, which is specific to males.

2. Which of the following statements is true of mutations?

• A. Mutations can only occur by chance.
• B. Mutations produce sperm and ova cells.
• C. Mutations occur through radiation or other environmental influences.
• D. Mutations help adenine combine with guanine to form the single spiral structure of DNA.

Correct answer: C

Rationale: The correct answer is C. Mutations can occur due to environmental influences such as radiation, chemicals, or other external factors, leading to changes in the DNA sequence. Choice A is incorrect because mutations can also occur due to errors in DNA replication, not solely by chance. Choice B is incorrect as mutations affect the DNA sequence itself, not the production of specific cells. Choice D is incorrect because mutations involve changes in the DNA sequence and do not specifically involve the formation of the DNA structure.

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. Which of the following statements is true of menstruation?

• A. During this time, the endometrium is shed.
• B. During this time, an unfertilized egg is discharged.
• C. During this time, a female can engage in sexual activity with her partner.
• D. During this time, a fertilized egg implants in the uterine lining.

Correct answer: B

Rationale: The correct statement regarding menstruation is that during this time, an unfertilized egg is discharged along with the shedding of the uterine lining. Choice A is incorrect because the endometrium is shed during menstruation. Choice C is incorrect as menstruation does not prevent a female from engaging in sexual activity with her partner. Choice D is incorrect as a fertilized egg does not undergo mitosis during menstruation but rather implants in the uterine lining for further development.

5. The _________ is the hollow organ within females in which the embryo and fetus develop.

• A. placenta
• B. ovum
• C. uterus
• D. amniotic sac

Correct answer: C

Rationale: The correct answer is C: uterus. The uterus is the organ where the embryo implants and the fetus develops during pregnancy. The placenta (choice A) is an organ that develops during pregnancy and provides nutrients and oxygen to the fetus, but it is not the organ where the embryo and fetus physically develop. The ovum (choice B) is the female reproductive cell or egg that is fertilized by the sperm to form an embryo, but it is not the organ where the embryo and fetus develop. The amniotic sac (choice D) is a membrane filled with amniotic fluid that surrounds and protects the fetus, but it is not the organ where the embryo and fetus physically develop.

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