Nursing Elites

1. Which of the following is true of homozygous traits?

• A. They are haploid
• B. They are denoted AA
• C. They are denoted aa
• D. They are denoted Aa

Correct answer: B

Rationale: Homozygous traits have two identical forms of the gene, either both dominant (AA) or both recessive (aa). Therefore, choices B and C are true for homozygous traits. Choice A is incorrect because being haploid refers to having a single set of chromosomes, not necessarily homozygous traits. Choice D is incorrect as homozygous traits have identical alleles, so they are not denoted as Aa.

2. Huntington’s disease is carried on the dominant allele. In a situation where two heterozygous parents have the disease, what percentage of their offspring are predicted to be disease-free?

• A. 0%
• B. 25%
• C. 50%
• D. 100%

Correct answer: B

Rationale: In this scenario, both parents are heterozygous for Huntington's disease, meaning each carries one dominant allele (representing the disease) and one recessive allele (representing no disease). When they have offspring, there is a 25% chance that each child will inherit two recessive alleles, making them disease-free. The Punnett square for two heterozygous parents (Hh x Hh) yields a 25% probability of offspring being homozygous recessive (hh) and therefore disease-free. Choice A (0%) is incorrect because there is a possibility of disease-free offspring. Choice C (50%) is incorrect as it represents the likelihood of being a carrier. Choice D (100%) is incorrect as all offspring will not be disease-free in this scenario.

3. Why do cells need to use exocytosis?

• A. To obtain energy
• B. To defend against invaders
• C. To remove waste products
• D. To undergo division

Correct answer: C

Rationale: Cells need to use exocytosis to remove waste products from the cell. Exocytosis is a process where cells release molecules or substances outside the cell by fusing vesicles with the cell membrane. This process is crucial for maintaining cellular homeostasis by efficiently eliminating waste materials. Choices A, B, and D are incorrect because exocytosis is specifically involved in the expulsion of molecules, not for obtaining energy, defending against invaders, or cell division.

4. Choose the two bases that have two carbon rings:

• A. Adenine
• B. Cytosine
• C. Thymine
• D. Guanine

Correct answer: A

Rationale: Adenine and guanine have two carbon rings and are known as purines. These bases are found in nucleic acids such as DNA and RNA. Adenine (option A) and guanine (option D) are the correct choices as they both have two carbon rings in their molecular structure. Cytosine (option B) and thymine (option C) have a single carbon ring each, making them incorrect choices for bases with two carbon rings.

5. Muscles are connected to bones by ______, and bones are connected to each other by ______.

• A. Muscles
• B. Tendons, ligaments
• C. Muscles
• D. Ligaments

Correct answer: B

Rationale: Muscles are connected to bones by tendons, which allow the muscle to exert force on the bone for movement. Bones are connected to each other by ligaments, which provide stability and support to the joints between bones. This relationship between muscles, tendons, bones, and ligaments is essential for proper movement and function of the musculoskeletal system. Choice A is incorrect because muscles are not directly connected to bones; tendons serve as the connection between muscles and bones. Choice D is incorrect because ligaments connect bones to each other, not muscles to bones.

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