ATI TEAS Practice Science Test

Correct Answer: A

Rationale: The correct answer is A: Cell. Cells are the most basic unit of structure in living things because they are the building blocks of all living organisms. Cells perform all the necessary functions for life, such as growth, reproduction, and energy production. Organelles are structures within cells, not the basic unit themselves. Oxygen is a vital component for life but not a structural unit. Pigments are molecules that give color and have specific functions in organisms but are not the basic unit of structure. Therefore, the correct choice is A: Cell.

Correct Answer: C

Rationale: The correct answer is C: Inverse correlation. Negative variation refers to a situation where one variable increases while the other decreases, showing an inverse relationship. This is different from non-correlation (A), which implies no relationship between variables. Direct correlation (B) indicates both variables moving in the same direction, while positive correlation (D) implies both variables increasing together. Therefore, C is the only choice that accurately represents negative variation.

Correct Answer: A

Rationale: The correct answer is A: Cell. Cells are the most basic unit of structure in living things because they are the building blocks of all living organisms. Cells perform all the necessary functions for life, such as growth, reproduction, and energy production. Organelles are structures within cells, not the basic unit themselves. Oxygen is a vital component for life but not a structural unit. Pigments are molecules that give color and have specific functions in organisms but are not the basic unit of structure. Therefore, the correct choice is A: Cell.

Correct Answer: B

Rationale: To convert grams to kilograms, we divide by 1000 since there are 1000 grams in a kilogram. Therefore, 1800 grams divided by 1000 equals 1.8 kilograms. Choice B is correct. Choice A is incorrect because 0.18 is the result of dividing by 10, not 1000. Choice C is incorrect as it is 10 times the correct answer. Choice D is incorrect as it is 100 times the correct answer.

Correct Answer: C

Rationale: The correct answer is C because fetal waste is passed down the umbilical cord to the mother's circulatory system. The developing fetus eliminates metabolic wastes primarily through the placenta, which acts as a filter between the fetal and maternal circulatory systems. Metabolic wastes from the fetus, such as carbon dioxide and urea, diffuse through the placenta into the mother's bloodstream for elimination by her kidneys and lungs. This process ensures that the fetus's metabolic wastes are effectively removed without burdening its own developing organs. Choices A, B, and D are incorrect: A: The developing fetus does produce metabolic wastes, which need to be eliminated for proper development. B: Fetal waste does not pass through the mother's digestive system; it would be harmful to both the mother and fetus. D: Fetal waste does not exit the mother's body via the vagina; this is not a mechanism for waste elimination in utero.