TEAS 7 practice test science

Correct Answer: B

Rationale: Fingernails and toenails are primarily made of a protein called keratin. Keratin is a tough, fibrous protein that provides structure and strength to nails, hair, and the outer layer of skin. Collagen, as mentioned, is found in the dermis and is not the primary component of nails. Melanin provides pigment to the skin and hair, not the structure of nails. Sebum is an oily substance produced by the skin's sebaceous glands and is not a structural component of nails.

Correct Answer: C

Rationale: Momentum is calculated as the product of an object's mass and its velocity. When the mass remains constant and the velocity doubles, the momentum will increase by a factor of 2 (doubling) due to the increase in velocity. Therefore, the momentum will quadruple (2 x 2 = 4) when the velocity doubles. This relationship between momentum and velocity showcases the direct proportionality of momentum to velocity, given a constant mass. Choices A, B, and D are incorrect. Momentum does not simply double or halve when the velocity doubles; it quadruples as it is directly proportional to the velocity. Hence, the correct answer is C, where momentum quadruples in this scenario.

Correct Answer: B

Rationale: - A) Ecosystem refers to a biological community of interacting organisms and their physical environment. - B) Community specifically refers to a group of organisms of different species living in the same place and interacting with each other. - C) Population refers to a group of individuals of the same species living in the same area. - D) Niche refers to the role or function of an organism or species within an ecosystem. In this context, the term for a group of organisms living in the same place and interacting with each other is best described as a community because it involves multiple species interacting within a shared habitat.

Correct Answer: C

Rationale: The cerebellum is the part of the brain that plays a crucial role in the regulation of balance, coordination, and posture. It receives information from the sensory systems, the spinal cord, and other parts of the brain to coordinate voluntary movements. While the thalamus is involved in relaying sensory and motor signals to the cerebral cortex, the cerebrum is responsible for higher brain functions such as thought and action. The hypothalamus is involved in various bodily functions including the regulation of body temperature, hunger, and thirst, but it is not primarily responsible for balance, coordination, and posture. Therefore, the correct answer is the cerebellum.

Correct Answer: B

Rationale: The correct answer is B: Focal length. Focal length is the distance between the center of a lens or curved mirror and its focal point. It determines how strongly the lens converges or diverges light, affecting the image formation. Aperture, choice A, refers to the opening through which light enters the lens, controlling the amount of light passing through. Refractive index, choice C, measures how much light bends when passing through a medium, affecting the speed of light. Lens thickness, choice D, is the physical dimension of the lens, influencing optical properties and compatibility with frames.