Nursing Elites

1. Which type of mutation involves a change in the number of chromosomes?

• A. Point mutation
• B. Frameshift mutation
• C. Missense mutation
• D. Aneuploidy

Correct answer: D

Rationale: A) Point mutation involves a change in a single nucleotide base pair within the DNA sequence. B) Frameshift mutation involves the insertion or deletion of nucleotides, causing a shift in the reading frame of the genetic code. C) Missense mutation involves a single nucleotide change that results in a codon that codes for a different amino acid. D) Aneuploidy involves a change in the number of chromosomes, where an individual may have an extra chromosome (trisomy) or a missing chromosome (monosomy). Aneuploidy can lead to genetic disorders such as Down syndrome (trisomy 21) or Turner syndrome (monosomy X). Changing the number of chromosomes is a characteristic feature of aneuploidy, making it the correct answer. Point mutation, frameshift mutation, and missense mutation do not involve a change in the number of chromosomes and are focused on alterations at the nucleotide level within the DNA sequence.

2. What is a rod-shaped structure that forms when a single DNA molecule and its associated proteins coil tightly before cell division?

• A. Centromere
• B. Chromatid
• C. Chromosome
• D. Gene

Correct answer: C

Rationale: A chromosome is a rod-shaped structure that forms when a single DNA molecule and its associated proteins coil tightly before cell division. It contains the genetic material and is essential for cell division and replication. The centromere is a specific region of a chromosome that plays a role in cell division. A chromatid is one half of a duplicated chromosome, and a gene is a unit of heredity responsible for specific traits. Therefore, the correct answer is 'Chromosome' as it represents the entire condensed DNA molecule during cell division.

3. What is the term for a genetic disorder caused by a mutation in a mitochondrial gene?

• A. Autosomal dominant disorder
• B. Autosomal recessive disorder
• C. Sex-linked disorder
• D. Mitochondrial disorder

Correct answer: D

Rationale: A) Autosomal dominant disorder: This type of genetic disorder is caused by a mutation in one copy of an autosomal gene. It is not related to mitochondrial gene mutations. B) Autosomal recessive disorder: This type of genetic disorder is caused by mutations in both copies of an autosomal gene. It is not related to mitochondrial gene mutations. C) Sex-linked disorder: This type of genetic disorder is caused by mutations in genes located on the sex chromosomes (X or Y). It is not related to mitochondrial gene mutations. D) Mitochondrial disorder: Mitochondrial disorders are genetic disorders caused by mutations in genes located in the mitochondria, the energy-producing structures within cells. These disorders are inherited maternally and can affect various organs and systems in the body due to the role of mitochondria in energy production.

4. The term that refers to the specific role and position an organism occupies within an ecosystem is called a:

• A. Habitat
• B. Niche
• C. Population
• D. Biome

Correct answer: B

Rationale: A) Habitat refers to the specific physical environment where an organism lives, including the biotic and abiotic factors present. While the habitat is important for an organism's survival, it does not encompass the specific role and interactions of the organism within the ecosystem. B) Niche refers to the specific role and position an organism occupies within an ecosystem, including its interactions with other organisms and its physical environment. This includes the organism's feeding habits, behavior, preferred habitat, and how it obtains resources. The niche of an organism is crucial in determining its impact on the ecosystem and its relationships with other species. C) Population refers to a group of individuals of the same species living in a specific area and interacting with each other. While populations play a role in ecosystems, they do not specifically describe the role and position of an individual organism within the ecosystem. D) Biome refers to a large geographical area characterized by its climate, fauna, and flora. It is a broader concept than niche, habitat, or population, focusing on the overall characteristics of the environment rather than the specific role of an individual organism.

5. What controls the involuntary, rhythmic contractions of the heart muscle?

• A. Lungs
• B. Brain
• C. Spinal cord
• D. Sinoatrial node (located within the heart)

Correct answer: D

Rationale: The correct answer is D: Sinoatrial node (located within the heart). The involuntary, rhythmic contractions of the heart muscle are controlled by a specialized group of cells located within the heart called the sinoatrial node (SA node). The SA node acts as the heart's natural pacemaker, producing electrical impulses that regulate the heart rate and synchronize the contractions of the heart muscle. Choices A, B, and C (Lungs, Brain, Spinal cord) are not responsible for directly influencing the rhythmic contractions of the heart muscle.

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