TEAS 7 science practice questions

Correct Answer: B

Rationale: The shift in the peppered moth population towards more dark moths in England after the Industrial Revolution exemplifies natural selection acting on pre-existing variation. Initially, light-colored moths were well-camouflaged against lichen-covered tree trunks, but with industrial pollution darkening the tree trunks, dark-colored moths gained a survival advantage. This change reflects how the environment favored dark moths over light ones, illustrating natural selection. The process illustrates how organisms with traits advantageous in a changing environment are more likely to survive and reproduce, leading to the prevalence of those traits in the population over time. The choices of artificial selection (A), punctuated equilibrium (C), and Lamarckism (D) are not applicable in this scenario. Artificial selection involves intentional breeding by humans, punctuated equilibrium refers to rapid bursts of evolution followed by periods of stability, and Lamarckism suggests the inheritance of acquired characteristics, none of which align with the observed shift in moth populations based on environmental changes.

Correct Answer: C

Rationale: Smooth muscle is the correct answer. It is the involuntary muscle tissue found in the walls of blood vessels and organs like the stomach and intestines. Smooth muscle is responsible for various involuntary movements in the body, such as peristalsis in the digestive system and regulating blood flow in blood vessels. Skeletal muscle is voluntary and attached to bones for movement. Cardiac muscle is specific to the heart and not found in blood vessel walls or organs like the stomach and intestines. Striated muscle refers to both skeletal and cardiac muscle due to their striped appearance under a microscope, but it does not specifically describe the involuntary muscle tissue in the walls of blood vessels and organs as asked in the question.

Correct Answer: D

Rationale: A) Made up of cells: All living organisms are composed of one or more cells, a fundamental characteristic of life as defined by cell theory. B) Able to reproduce: Reproduction is a key characteristic of living organisms to pass on genetic information. C) Require energy: Energy is essential for carrying out life processes like growth and maintenance of homeostasis. D) Non-motile: While some living organisms are non-motile, movement is common in many organisms for survival activities like finding food, escaping predators, and responding to the environment. Therefore, being non-motile is not a universal characteristic of living organisms, making it the correct answer in this context.

Correct Answer: B

Rationale: The correct answer is B: Thoracic duct. The thoracic duct is the largest lymphatic vessel in the body and is responsible for draining lymph from most of the body. The jugular vein, subclavian vein, and aorta are not lymphatic vessels responsible for draining lymph. The jugular vein and subclavian vein are blood vessels, while the aorta is the main artery that carries oxygenated blood from the heart. Understanding the role and anatomy of the lymphatic system is crucial for comprehending the body's immune response and fluid balance.

Correct Answer: B

Rationale: The 'lock-and-key' model describes the specificity of the interaction between enzymes and their substrates. In this model, the enzyme's active site acts like a lock that can only be opened by the specific substrate molecule, which serves as the key. This specific binding ensures that enzymes catalyze particular reactions and do not interact with other molecules indiscriminately. Protein folding (option A) is the process by which a protein attains its functional three-dimensional structure but is not directly related to the lock-and-key model. Muscle contraction (option C) and blood clotting (option D) are complex biological processes but are not directly associated with the lock-and-key model of enzyme-substrate interaction.