Nursing Elites

1. After the Industrial Revolution, the population of peppered moths in England shifted towards more dark moths. This is an example of:

• A. Artificial selection (selective breeding by humans for desired traits)
• B. Natural selection acting on pre-existing variation
• C. Punctuated equilibrium (rapid bursts of evolution)
• D. Lamarckism (inheritance of acquired characteristics)

Correct answer: B

Rationale: The shift in the peppered moth population towards more dark moths in England after the Industrial Revolution exemplifies natural selection acting on pre-existing variation. Initially, light-colored moths were well-camouflaged against lichen-covered tree trunks, but with industrial pollution darkening the tree trunks, dark-colored moths gained a survival advantage. This change reflects how the environment favored dark moths over light ones, illustrating natural selection. The process illustrates how organisms with traits advantageous in a changing environment are more likely to survive and reproduce, leading to the prevalence of those traits in the population over time. The choices of artificial selection (A), punctuated equilibrium (C), and Lamarckism (D) are not applicable in this scenario. Artificial selection involves intentional breeding by humans, punctuated equilibrium refers to rapid bursts of evolution followed by periods of stability, and Lamarckism suggests the inheritance of acquired characteristics, none of which align with the observed shift in moth populations based on environmental changes.

2. Which of the following lobes of the brain is primarily responsible for vision?

• A. Frontal
• B. Occipital
• C. Parietal
• D. Temporal

Correct answer: B

Rationale: The occipital lobe is primarily responsible for processing visual information. It contains the primary visual cortex, which plays a key role in interpreting visual stimuli. The frontal lobe is more associated with functions such as decision-making and problem-solving, making choice A incorrect. The parietal lobe is involved in processing sensory information but not specifically vision, making choice C incorrect. The temporal lobe is responsible for functions like memory and auditory processing, so choice D is also incorrect.

3. Why does a prism separate white light into its constituent spectral components?

• A. It absorbs certain colors
• B. Different colors experience varying speeds within the prism
• C. It bends all colors with the same magnitude
• D. It reflects specific colors

Correct answer: B

Rationale: A prism separates white light into its constituent spectral components because different colors experience varying speeds within the prism due to their different wavelengths. This causes the light to refract at different angles, resulting in the separation of colors. When light enters the prism, it undergoes dispersion, where different colors are refracted at different angles due to their unique wavelengths. This phenomenon is known as chromatic dispersion. Choice A is incorrect because a prism does not absorb colors but refracts and disperses them. Choice C is incorrect because a prism refracts different colors at different angles, not with the same magnitude. Choice D is incorrect because a prism does not reflect colors but refracts and disperses them based on their wavelengths.

4. What is the name of the regulatory region in a gene that controls its expression?

• A. Exon
• B. Intron
• C. Promoter
• D. Enhancer

Correct answer: C

Rationale: A) Exon: Exons are the coding regions of a gene that are transcribed into mRNA and eventually translated into proteins. Exons do not regulate gene expression. B) Intron: Introns are non-coding regions of a gene that are removed during RNA processing and do not play a direct role in controlling gene expression. C) Promoter: The promoter is a regulatory region located at the beginning of a gene that initiates the process of transcription by binding transcription factors and RNA polymerase. It plays a crucial role in controlling gene expression. D) Enhancer: Enhancers are regulatory regions that can be located far from the gene they regulate and can increase the transcription of a gene. While enhancers are important for gene expression, the specific region that controls gene expression is the promoter. Therefore, the correct answer is C) Promoter, as it is the regulatory region in a gene that controls its expression by initiating transcription.

5. Which of the following components is found in DNA?

• A. Uracil
• B. Deoxyribose
• C. Guanine
• D. Phosphate group

Correct answer: B

Rationale: The correct answer is B: Deoxyribose. DNA is composed of nucleotides containing deoxyribose sugar, phosphate group, and nitrogenous bases (adenine, thymine, guanine, and cytosine). Deoxyribose is the sugar component specific to DNA, while ribose is found in RNA. Guanine (choice C) is a nitrogenous base present in both DNA and RNA. Uracil (choice A) is a nitrogenous base specific to RNA, replacing thymine found in DNA. The phosphate group (choice D) is an essential part of nucleotides in both DNA and RNA, providing the backbone structure for the nucleic acid chains.

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