HESI A2 Biology Practice Test

Correct Answer: A

Rationale: The correct answer is A because the nucleus stores the cell's genetic material, DNA, which contains instructions for cell function and growth. This is crucial for cell division, protein synthesis, and overall cell activities. Choice B is incorrect because the nucleus does not provide structural support to the cell. Choice C is incorrect as protein synthesis primarily occurs in the ribosomes. Choice D is incorrect as energy production from food takes place in the mitochondria, not the nucleus.

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.

Correct Answer: B

Rationale: The correct answer is B: Prokaryotic cells have a capsule. This is because the capsule is a protective layer outside the cell wall that helps the prokaryotic cell adhere to surfaces and evade the immune system. Prokaryotic cells do not have a nucleus (choice A), membrane-bound organelles (choice C), or the ability to move on their own (choice D). The absence of a nucleus and membrane-bound organelles distinguishes prokaryotic cells from eukaryotic cells. Choice D is incorrect because prokaryotic cells can move using various mechanisms such as flagella or pili.

Correct Answer: A

Rationale: To convert cm to mm, you multiply by 10 since 1 cm = 10 mm. Therefore, to convert 8 cm to mm, you multiply 8 by 10 which equals 80 mm. Choice A (80 mm) is correct. Option B (800 mm) is incorrect as it is 10 times the correct answer, making it too large. Option C (8 mm) is incorrect as it represents the original measurement in cm, not the conversion to mm. Option D (0.8 mm) is incorrect as it is one-tenth of the correct answer, making it too small.

Correct Answer: D

Rationale: The correct answer is D: They are denoted Aa. Heterozygous traits refer to the presence of different alleles at a specific gene locus. In this case, A and a represent two different alleles for the same trait. When an individual is heterozygous, one allele is dominant (A) and the other is recessive (a). Therefore, the correct notation for a heterozygous trait is Aa. Option A is incorrect because heterozygous traits are not haploid (having one set of chromosomes), but diploid (having two sets). Option B is incorrect as it denotes a homozygous dominant genotype. Option C is incorrect as it denotes a homozygous recessive genotype.