which structure in the eye is responsible for detecting light

ATI TEAS 7

ATI TEAS Practice Test Science

1. Which structure in the eye is responsible for detecting light?

A. Cornea
B. Retina
C. Lens
D. Iris

Correct answer: B

Rationale: The retina is the correct answer as it is the light-sensitive structure in the eye that detects light and converts it into signals for the brain to process visual information. The cornea is the transparent outer covering of the eye that helps to focus incoming light onto the lens. The lens further focuses the light onto the retina, which is where the actual light detection and signal conversion occur. The iris, on the other hand, controls the amount of light entering the eye by adjusting the size of the pupil but is not directly responsible for detecting light.

2. What is the function of valves in arteries?

A. To maintain high blood pressure for the proper diffusion of nutrients in capillaries.
B. To prevent backflow of blood due to high pressure away from the heart.
C. As a vestigial trait from evolution, like the appendix, that serves no purpose.
D. Valves are absent in arteries but present in veins.

Correct answer: B

Rationale: Valves in arteries serve the crucial function of preventing backflow of blood. Arteries carry blood at high pressure away from the heart, and the valves ensure that blood flows in one direction, towards the capillaries, to maintain efficient circulation. Without these valves, there would be a risk of blood flowing backward, compromising the effectiveness of blood circulation in the body. Choices A, C, and D are incorrect. Choice A incorrectly suggests that valves maintain high blood pressure for nutrient diffusion in capillaries, which is not their function. Choice C inaccurately compares valves to vestigial traits, like the appendix, implying they serve no purpose, which is untrue. Choice D is incorrect as valves are indeed present in arteries to regulate blood flow, not just in veins.

3. The Hardy-Weinberg equilibrium describes a population that is:

A. Undergoing rapid evolution due to strong directional selection.
B. Not evolving and at genetic equilibrium with stable allele frequencies.
C. Experiencing a founder effect leading to a reduction in genetic diversity.
D. Dominated by a single homozygous genotype that eliminates all variation.

Correct answer: B

Rationale: The Hardy-Weinberg equilibrium describes a theoretical population in which allele frequencies remain constant from generation to generation, indicating that the population is not evolving. This equilibrium occurs under specific conditions: no mutation, no gene flow, random mating, a large population size, and no natural selection. In this scenario, all genotypes are in proportion to the allele frequencies, and genetic diversity is maintained. Options A, C, and D do not accurately describe a population in Hardy-Weinberg equilibrium. Option A suggests rapid evolution due to strong directional selection, which would disrupt the equilibrium. Option C mentions a founder effect, which can reduce genetic diversity but is not a characteristic of a population in Hardy-Weinberg equilibrium. Option D describes a population dominated by a single homozygous genotype, which also does not align with the genetic diversity seen in a population at Hardy-Weinberg equilibrium.

4. What is the law of conservation of energy?

A. Energy cannot be created, only destroyed
B. Energy can be created but not destroyed
C. Energy can neither be created nor destroyed, only transformed from one form to another
D. Energy is always created in any process

Correct answer: C

Rationale: The correct answer is C: 'Energy can neither be created nor destroyed, only transformed from one form to another.' The law of conservation of energy is a fundamental principle in physics. It states that the total energy in a closed system remains constant over time. Energy can change from one form to another (e.g., potential energy to kinetic energy), but the total amount of energy remains the same. Choices A, B, and D are incorrect because they do not accurately represent the law of conservation of energy. Energy is not created or destroyed according to this law, but rather transformed.

5. Which of the following describes a typical gas?

A. Indefinite shape and indefinite volume
B. Indefinite shape and definite volume
C. Definite shape and definite volume
D. Definite shape and indefinite volume

Correct answer: B

Rationale: The correct answer is B: 'Indefinite shape and definite volume.' A gas does not have a definite shape as it takes the shape of its container, conforming to its surroundings. However, a gas does have a definite volume because it fills the entire volume of the container it occupies. This characteristic allows gases to expand to fill the available space provided by the container, while their volume remains constant within that container. Choice A is incorrect because gases do not have an indefinite volume but rather a definite volume. Choice C is incorrect as gases do not have a definite shape but take the shape of their container. Choice D is incorrect as gases do not have a definite shape and their volume is definite, not indefinite.