ATI TEAS Practice Test Science

Correct Answer: B

Rationale: The correct answer is B: Cardiac muscle. Cardiac muscle is the specialized muscle found in the walls of the heart. It contracts involuntarily to pump blood throughout the body, ensuring circulation. Smooth muscle is typically found in organs like the intestines and blood vessels, aiding in their functions. Skeletal muscle is attached to bones and plays a vital role in movement and posture. Voluntary muscle is a general term for skeletal muscles that are under conscious control, unlike cardiac muscle which contracts involuntarily to maintain the heart's continuous pumping action.

Correct Answer: B

Rationale: The cerebellum is the correct answer as it is the part of the brain responsible for controlling balance and coordination in the body. It receives input from various parts of the brain, spinal cord, and sensory systems to help coordinate voluntary movements. The cerebrum (choice A) is mainly involved in higher brain functions such as thinking, decision-making, and voluntary movements but not specifically balance and coordination. The medulla (choice C) is essential for functions like breathing, heart rate, and blood pressure regulation but not primarily for balance and coordination. The thalamus (choice D) acts as a relay station for sensory information but is not primarily responsible for balance and coordination.

Correct Answer: B

Rationale: The iris is the correct answer as it controls the amount of light that enters the eye by adjusting the size of the pupil. The cornea is responsible for focusing light onto the retina, the retina detects light at the back of the eye, and the lens helps in further focusing light onto the retina. The iris, through changing the size of the pupil, regulates the amount of light reaching the eye, making it the part that controls the entry of light.

Correct Answer: A

Rationale: An atom's charge is determined by the difference between the number of protons and electrons. Since the atom has 17 protons and 19 electrons, the net charge is positive. The excess of two electrons compared to protons results in a positive charge. Choice B (Negative) is incorrect because the atom has more protons than electrons, leading to a positive charge. Choice C (Neutral) is incorrect because the atom has an imbalance between protons and electrons, resulting in a charge. Choice D (Cannot be determined) is incorrect as the charge can be determined based on the given information.

Correct Answer: A

Rationale: In an experiment, the independent variable is the factor that is deliberately manipulated or changed by the researcher. The botanist is likely altering the temperature to observe its effect on the plants. Therefore, temperature is the independent variable in the botanist's experiment. Choice B, root tissue, is not the independent variable as it is not the factor being intentionally changed in the experiment. Choice C, light exposure, and choice D, root length, are also not the independent variables as they are not the factors being purposely manipulated by the researcher in this scenario.