TEAS 7 Science Practice Test

Correct Answer: A

Rationale: The correct answer is A: smooth endoplasmic reticulum. The smooth endoplasmic reticulum is the site of lipid synthesis due to the presence of enzymes involved in lipid metabolism. It lacks ribosomes, unlike the rough endoplasmic reticulum, which is primarily involved in protein synthesis. The Golgi apparatus functions in processing and packaging proteins for secretion. Ribosomes are involved in protein synthesis, not lipid synthesis. Therefore, the smooth endoplasmic reticulum is the organelle responsible for lipid synthesis.

Correct Answer: A

Rationale: The correct answer is A because atomic radius generally increases from top to bottom within a group and decreases from left to right across a period on the periodic table. This trend is due to the increasing number of energy levels (shells) as you move down a group, leading to larger atomic radii. Moving from left to right across a period, atomic radius decreases due to increasing effective nuclear charge pulling the electrons closer to the nucleus. Choices B, C, and D are incorrect as they do not accurately describe the trend of atomic radius across the periodic table.

Correct Answer: D

Rationale: The correct answer is D: high polarity. Water molecules are polar, with a slightly positive end (hydrogen) and a slightly negative end (oxygen). This polarity allows water to form hydrogen bonds with other polar molecules, like ionic salt compounds, facilitating their dissolution. Adhesion (A) is the ability of water to stick to other substances, cohesion (B) is the ability of water molecules to stick to each other, and high specific heat (C) is the ability of water to resist temperature changes. These properties are not directly related to water's ability to dissolve ionic salt compounds.

Correct Answer: C

Rationale: The correct answer is C: controlled experiment. In a controlled experiment, the researcher manipulates one or more independent variables to observe the effect on the dependent variable, while controlling for other variables. In this scenario, the researcher is controlling the conditions and variables to study the impact of the manipulated independent variable on the dependent variable. Incorrect choices: A: Field experiment involves conducting research in real-world settings, which may not necessarily involve manipulation of variables. B: Natural experiment involves observing naturally occurring events without any manipulation by the researcher. D: Observational study involves observing and recording data without any intervention or manipulation of variables.

Correct Answer: C

Rationale: The correct answer is C: synapse. Neurotransmitters are chemicals that transmit signals between neurons. The synapse is the gap between neurons where these chemical messages are transmitted. Schwann cells are responsible for myelinating axons, ganglion is a cluster of nerve cell bodies, and the axon is the part of a neuron that carries the signal away from the cell body. Therefore, the synapse is the structure specifically involved in transmitting neurotransmitters between neurons.