HESI A2 Biology Practice Test

Correct Answer: C

Rationale: Anaerobic respiration occurs in bacteria because they live in environments with low oxygen levels. Bacteria adapt to anaerobic conditions by utilizing alternative pathways to generate energy without oxygen. This process allows them to survive and thrive in oxygen-deprived environments. The other choices are incorrect because animals require oxygen for aerobic respiration, plants use sunlight for photosynthesis, and option D is incorrect as bacteria indeed undergo anaerobic respiration in low oxygen environments.

Correct Answer: B

Rationale: The correct answer is B because animal cells do not use chloroplasts to gain energy, they use mitochondria for cellular respiration. Lysosomes in animal cells break down old cells (A) and plant cells have a cell wall (C). Choice D is incorrect as B is false.

Correct Answer: A

Rationale: The correct answer is A: Connective tissue. Fat is a type of adipose tissue, which is a specialized form of connective tissue that stores energy in the form of fat cells. Connective tissue provides support, structure, and insulation to the body. Muscle tissue (B) is responsible for movement, nervous tissue (C) transmits signals, and epithelial tissue (D) forms protective barriers. Fat does not perform these functions, hence choices B, C, and D are incorrect.

Correct Answer: B

Rationale: The correct answer is B: Carrier proteins. Carrier proteins change shape to facilitate the movement of specific molecules across the membrane. They bind to the target molecule on one side of the membrane, undergo a conformational change, and release the molecule on the other side. This process is selective and energy-dependent. Option A (Diffusion) is incorrect because diffusion is a passive process that does not involve proteins changing shape to transport molecules. Option C (Channel proteins) is incorrect because channel proteins provide a passageway for specific molecules to move across the membrane but do not change shape to transport molecules. Option D (None of the above) is incorrect because carrier proteins specifically fit the description provided in the question.

Correct Answer: C

Rationale: The correct answer is C: The renal system. The renal system consists of the kidneys, ureters, bladder, and urethra, all of which are involved in the formation and release of urine. The kidneys filter waste products from the blood, and the ureters transport urine from the kidneys to the bladder. The bladder stores urine before it is eliminated through the urethra. Choice A, the digestive system, is incorrect because it primarily involves the organs responsible for digestion and absorption of nutrients, such as the stomach, intestines, and liver. Choice B, the reproductive system, is incorrect because it includes organs like the ovaries, testes, and uterus, involved in reproduction, not urine formation. Choice D, the kidney system, is incorrect as it is not a commonly used term to describe the collective organs involved in urine formation and excretion.