HESI A2
HESI A2 Biology 2024 Questions
Question 1 of 5
What are saturated fats saturated with?
Correct Answer: A
Rationale: Saturated fats are saturated with hydrogen atoms. This means that each carbon atom in the fatty acid chains forming saturated fats is bonded to as many hydrogen atoms as possible. This saturation results in the fatty acid chains being straight and closely packed together, making saturated fats solid at room temperature. Choice B (Carbon atoms), C (Oxygen atoms), and D (Nitrogen atoms) are incorrect because saturated fats are specifically saturated with hydrogen atoms, not carbon, oxygen, or nitrogen atoms.
Question 2 of 5
Ocean waves may tear sponges into pieces, each of which may grow into a new sponge. What is this form of reproduction called?
Correct Answer: D
Rationale: Fragmentation is the form of asexual reproduction where an organism breaks into fragments, and each fragment can grow into a new individual. In the case of sponges being torn into pieces by ocean waves, each piece has the potential to develop into a new sponge, making fragmentation the correct answer in this scenario. Budding is a form of asexual reproduction where a new organism develops as an outgrowth from the parent organism. Vegetative propagation involves the growth of new individuals from plant parts like stems or roots. Binary fission is a method of reproduction seen in some single-celled organisms where one cell divides into two identical cells.
Question 3 of 5
How many pairs of homologous chromosomes do humans have?
Correct Answer: D
Rationale: The correct answer is D: 46. Humans have 23 pairs of chromosomes, which include 22 pairs of autosomes and 1 pair of sex chromosomes. Homologous chromosomes are pairs of chromosomes that contain the same genes, one from each parent. Therefore, humans have a total of 46 chromosomes, with 23 pairs of homologous chromosomes. Choices A, B, and C are incorrect as they do not represent the total number of chromosomes in humans or the number of pairs of homologous chromosomes.
Question 4 of 5
What happens to messenger RNA when it reaches the cytoplasm?
Correct Answer: A
Rationale: Messenger RNA (mRNA) carries genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm. When mRNA reaches the cytoplasm, it attaches to a ribosome. The ribosome functions as the site for protein synthesis through translation, where the genetic code carried by mRNA is read and translated into a specific sequence of amino acids. Choices B, C, and D are incorrect because mRNA does not unzip, expose nitrogen bases, pair with DNA bases, or pull free of the DNA strand in the cytoplasm. The primary function of mRNA in the cytoplasm is to serve as a template for protein synthesis by binding to ribosomes.
Question 5 of 5
In an example of a male with hemophilia and a female carrier, what percentage of the offspring is predicted to be carriers only?
Correct Answer: C
Rationale: In this scenario, the male offspring will inherit the X chromosome with the hemophilia gene from the mother, as males have one X chromosome inherited from their mother. The female offspring will inherit one normal X chromosome from the father and one X chromosome with the hemophilia gene from the mother, making them carriers of the hemophilia trait. Therefore, 50% of the offspring will be carriers only. Option A (0%) is incorrect as female offspring will inherit the X chromosome with the hemophilia gene from the mother. Option B (25%) is incorrect as the female offspring will not be unaffected. Option D (100%) is incorrect as not all offspring will be carriers, only the female offspring.