Nursing Elites

1. What is the difference between homologous chromosomes and sister chromatids?

• A. Homologous chromosomes have the same genes but may have different alleles, while sister chromatids are identical copies of the same chromosome.
• B. Homologous chromosomes are only found in diploid cells, while sister chromatids are found in both haploid and diploid cells.
• C. Both homologous chromosomes and sister chromatids are genetically identical, but only sister chromatids separate during mitosis.
• D. Both homologous chromosomes and sister chromatids can separate during mitosis, but only homologous chromosomes have different alleles.

Correct answer: A

Rationale: Rationale: - Homologous chromosomes are pairs of chromosomes that have the same genes in the same order, one from each parent. While they carry the same genes, they may have different alleles (variants of a gene). - Sister chromatids are exact copies of each other, formed during DNA replication. They are held together by a centromere and are produced during the S phase of the cell cycle. - During meiosis, homologous chromosomes pair up and exchange genetic material through crossing over, leading to genetic variation. Sister chromatids separate during mitosis to ensure each daughter cell receives an identical copy of the genetic material.

2. What are the four main regions of the stomach?

• A. Pylorus, cecum, fundus, body
• B. Cardia, fundus, body, pylorus
• C. Duodenum, jejunum, ileum, cecum
• D. Cardia, fundus, body, ileum

Correct answer: B

Rationale: The correct answer is B: Cardia, fundus, body, pylorus. The four main regions of the stomach are the cardia (where food enters), fundus (upper part), body (largest part), and pylorus (exit part to the small intestine). These regions play specific roles in the digestion process. Choice A is incorrect because the cecum is part of the large intestine, not the stomach. Choice C lists parts of the small intestine, not the stomach. Choice D is incorrect as the ileum is the last part of the small intestine, not a region of the stomach.

3. What type of molecule forms the cell membrane and controls what enters and exits the cell?

• A. Proteins
• B. Carbohydrates
• C. Lipids
• D. Nucleic acids

Correct answer: C

Rationale: The cell membrane is primarily composed of lipids, specifically phospholipids, which form a lipid bilayer. This lipid bilayer controls what enters and exits the cell, providing a barrier that is selectively permeable. While proteins are also important components of the cell membrane and play various roles, lipids are the main structural component responsible for the membrane's permeability and function. Carbohydrates and nucleic acids are not the primary components of the cell membrane and do not have the same structural role as lipids.

4. What is the primary function of the lymphatic system?

• A. Transporting oxygen and nutrients to cells
• B. Carrying waste products away from tissues
• C. Regulating body temperature
• D. Producing red blood cells

Correct answer: B

Rationale: The primary function of the lymphatic system is to carry waste products away from tissues. Lymphatic vessels collect excess fluid, waste materials, and toxins from the body's tissues and transport them to the bloodstream for elimination. Choice A is incorrect because transporting oxygen and nutrients to cells is mainly the function of the circulatory system. Choice C is incorrect as regulating body temperature is primarily done by the body's thermoregulatory mechanisms. Choice D is incorrect because the production of red blood cells occurs in the bone marrow, not in the lymphatic system.

5. What information does a genotype provide that a phenotype does not?

• A. The genotype necessarily includes the proteins coded for by its alleles.
• B. The genotype will always display an organism's recessive alleles.
• C. The genotype must include the organism's physical characteristics.
• D. The genotype indicates what an organism's parents looked like.

Correct answer: A

Rationale: The genotype provides information about the specific genetic makeup of an organism, including the alleles it possesses for a particular trait. This information is not always directly reflected in the phenotype, which is the observable physical characteristics of an organism. The genotype determines the proteins coded for by its alleles, but the phenotype is the expression of those proteins in the organism's traits. Therefore, the genotype necessarily includes the proteins coded for by its alleles, a detail not provided solely by the phenotype.\nChoice B is incorrect because the genotype may include dominant alleles as well, not just recessive ones. Choice C is incorrect because the genotype refers to genetic information, not physical characteristics. Choice D is incorrect because the genotype does not directly indicate what an organism's parents looked like; it primarily describes the genetic information inherited from parents.

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