Nursing Elites

1. What is the major difference between somatic and germline mutations?

• A. Somatic mutations usually benefit the individual while germline mutations usually harm them.
• B. Since germline mutations only affect one cell, they are less noticeable than the rapidly dividing somatic cells.
• C. Somatic mutations are not expressed for several generations, but germline mutations are expressed immediately.
• D. Germline mutations are usually inherited while somatic mutations will affect only the individual.

Correct answer: D

Rationale: The major difference between somatic and germline mutations is that germline mutations are usually inherited and can be passed on to offspring, while somatic mutations occur in non-reproductive cells and only affect the individual in which they occur. This means that germline mutations have the potential to be present in future generations, while somatic mutations do not.

2. What type of bond holds water molecules together?

• A. Covalent bond
• B. Hydrogen bond
• C. Ionic bond
• D. Peptide bond

Correct answer: B

Rationale: The correct answer is B: Hydrogen bond. Hydrogen bonds are responsible for holding water molecules together. In a water molecule, the oxygen atom is slightly negative, and the hydrogen atoms are slightly positive, creating a partial positive and negative charge. This polarity allows hydrogen bonds to form between adjacent water molecules. Covalent bonds involve the sharing of electrons, ionic bonds involve transfer of electrons between ions, and peptide bonds are specific to linking amino acids in proteins, which are not relevant to water molecule interactions.

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 are the cellular functions of cilia and flagella?

• A. Cilia and flagella are responsible for cell movement.
• B. Cilia and flagella synthesize proteins.
• C. Cilia and flagella help protect the cell from its environment.
• D. Cilia and flagella have enzymes that help with digestion.

Correct answer: A

Rationale: Cilia and flagella are microtubule-based structures found on the surface of many eukaryotic cells. Their primary function is to facilitate cell movement. Cilia are short, numerous, and move in coordinated waving motions to move substances along the cell's surface. Flagella are longer and usually limited to one or a few per cell, providing a propeller-like movement for the cell. Both cilia and flagella aid in cell motility and are essential for various cellular functions, primarily involved in cell movement rather than protein synthesis, protection, or digestion. Therefore, choice A is correct as it accurately describes the primary function of cilia and flagella. Choices B, C, and D are incorrect as cilia and flagella are not involved in protein synthesis, cell protection, or digestion in cells.

5. What is the significance of studying pedigrees in human genetics?

• A. Predicting the exact outcome of genetic crosses in humans.
• B. Tracing the inheritance of complex traits with multiple contributing genes.
• C. Identifying carriers of dominant genetic disorders.
• D. Determining the risk of acquiring a specific mutation de novo.

Correct answer: B

Rationale: Pedigrees are diagrams that show the relationships within a family and can be used to track the inheritance patterns of specific traits or diseases. While pedigrees can provide information on the inheritance of single gene disorders (such as identifying carriers of dominant genetic disorders, as mentioned in option C), their primary significance lies in studying complex traits with multiple contributing genes. These traits do not follow simple Mendelian inheritance patterns and are influenced by both genetic and environmental factors. By analyzing pedigrees, researchers can identify patterns of inheritance for complex traits, such as polygenic diseases or traits influenced by gene-environment interactions. Therefore, option B is the most appropriate choice as it captures the main significance of studying pedigrees in human genetics.

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