TEAS Practice Test Science

Correct Answer: A

Rationale: The independent variable is what the researcher manipulates to observe its effect on the dependent variable. In this study, the botanist is testing if temperature affects root growth. Therefore, the independent variable is temperature (choice A). The botanist will change the temperature levels to see how it influences root growth. Choices B, C, and D are not the independent variable as the botanist is not directly manipulating seedlings, light, or root length to study the effect on root growth.

Correct Answer: B

Rationale: The correct answer is B: Skeletal muscle. Skeletal muscles are attached to bones and responsible for moving the skeleton through voluntary contractions. They are under conscious control, making them voluntary muscles. Cardiac muscle (A) is found in the heart and responsible for pumping blood. Smooth muscle (C) is found in organs and blood vessels, responsible for involuntary movements. Voluntary muscle (D) is a general term that can refer to both skeletal and smooth muscles, but in this context, it does not specifically address moving the skeleton.

Correct Answer: B

Rationale: The large intestine's main role is to absorb water and form feces. First, undigested material passes from the small intestine to the large intestine. Second, water is absorbed, making the stool more solid. Finally, the formed feces are stored until they are eliminated from the body. This process is crucial for maintaining proper hydration and eliminating waste. Choices A, C, and D are incorrect as they describe functions performed by other parts of the digestive system, such as the stomach and small intestine.

Correct Answer: A

Rationale: The correct answer is A: Helicase. Helicase is responsible for unwinding the double-stranded DNA during replication by breaking the hydrogen bonds between the base pairs. This allows the DNA strands to separate and serve as templates for the synthesis of new DNA strands by DNA polymerase. Ligase is responsible for joining the DNA fragments together, nuclease is involved in DNA repair by cutting out damaged DNA, and polymerase is responsible for synthesizing new DNA strands based on the template strands. Therefore, only helicase directly unwinds the double-stranded DNA during replication.

Correct Answer: D

Rationale: The correct answer is D: Vital capacity. Vital capacity is the maximum volume of air a person can exhale after maximum inhalation, including tidal volume, inspiratory reserve volume, and expiratory reserve volume. Tidal volume (A) is the volume of air inhaled and exhaled during normal breathing, not maximum inhalation. Total lung capacity (B) is the total volume of air the lungs can hold at maximum inflation, including residual volume. Ventilation rate (C) refers to the number of breaths taken per minute, not the volume of air that can be expelled after maximum inhalation. In summary, vital capacity is the correct choice as it specifically represents the maximum volume of air that can be expelled from the lungs after maximum inhalation.