which phenomenon explains the formation of rainbows in the sky

ATI TEAS 7

TEAS version 7 quizlet science

1. What phenomenon explains the formation of rainbows in the sky?

A. Diffraction
B. Interference
C. Refraction and dispersion of sunlight by water droplets
D. Reflection from clouds

Correct answer: C

Rationale: Rainbows are formed due to the refraction and dispersion of sunlight by water droplets in the atmosphere. When sunlight enters a water droplet, it is refracted, then internally reflected, and finally refracted again as it exits the droplet. This dispersion of light into its component colors creates the beautiful rainbow we see in the sky. Choice A, diffraction, involves bending of light around obstacles or through narrow openings, not the splitting of light into colors as seen in rainbows. Choice B, interference, refers to the phenomenon where two or more light waves overlap and interact, producing a pattern of light and dark bands, which is not the case with rainbows. Choice D, reflection from clouds, does not accurately describe the process involved in the formation of rainbows through refraction and dispersion of light by water droplets.

2. How does the respiratory system facilitate gas exchange between air and blood?

A. Diffusion
B. Exhalation
C. Inspiration
D. Ventilation

Correct answer: A

Rationale: The correct answer is 'Diffusion.' Diffusion is the process by which gases are exchanged between air in the alveoli and blood in the capillaries. Oxygen moves from the alveoli into the blood, while carbon dioxide moves from the blood into the alveoli through diffusion. Exhalation is the process of expelling air from the lungs, inspiration is the process of inhaling air into the lungs, and ventilation refers to the overall movement of air in and out of the lungs. While these processes are essential for the respiratory system to function, they are not directly responsible for the gas exchange between air and blood, which is primarily achieved through diffusion.

3. How can a single gene mutation lead to multiple phenotypes depending on the organism?

A. Pleiotropy describes the effect of one gene influencing multiple seemingly unrelated traits.
B. Epigenetics involves environmental factors modifying gene expression without altering the DNA sequence.
C. Genetic drift refers to random changes in allele frequencies within a population.
D. Gene regulation controls the timing and level of gene expression within an organism.

Correct answer: A

Rationale: A single gene mutation can lead to multiple phenotypes through pleiotropy, where one gene influences diverse traits or functions in an organism. This phenomenon occurs when the mutated gene affects different biochemical pathways, developmental processes, or cellular functions, resulting in a cascade of downstream effects that manifest as a variety of phenotypic outcomes. Choice B, epigenetics, involves modifications in gene expression influenced by environmental factors without altering the DNA sequence, which is not directly related to the question about single gene mutations causing multiple phenotypes. Choice C, genetic drift, refers to random changes in allele frequencies within a population, which is unrelated to the impact of a single gene mutation on multiple phenotypes. Choice D, gene regulation, focuses on controlling the timing and level of gene expression within an organism, which is not directly addressing how a single gene mutation can lead to diverse phenotypes.

4. What does bradycardia refer to in terms of heart rate?

A. Normal (60-100 bpm)
B. Slightly elevated (100-120 bpm)
C. Significantly elevated (>120 bpm)
D. Abnormally slow (<60 bpm)

Correct answer: D

Rationale: Bradycardia refers to an abnormally slow heart rate, typically defined as less than 60 beats per minute. This condition can result in inadequate blood flow to meet the body's demands. It is crucial to distinguish between bradycardia and tachycardia, which is a fast heart rate, as they require different management strategies. Options A, B, and C are incorrect because they describe normal, slightly elevated, and significantly elevated heart rates, respectively, rather than an abnormally slow heart rate characteristic of bradycardia. Recognizing bradycardia is essential for appropriate evaluation and intervention in clinical settings.

5. What is the functional group present in aldehydes?

A. Hydroxyl
B. Carbonyl
C. Ester
D. Amine

Correct answer: B

Rationale: The correct answer is B: Carbonyl. Aldehydes contain the functional group -CHO, which is a carbonyl group where a carbon atom is double-bonded to an oxygen atom and single-bonded to a hydrogen atom. This distinguishes aldehydes from other functional groups. Choice A, Hydroxyl (-OH), is not characteristic of aldehydes as it is found in alcohols. Choice C, Ester (-COOR), and choice D, Amine (-NH2), represent different functional groups not typically found in aldehydes. Therefore, the correct functional group present in aldehydes is the carbonyl group.