HESI A2
Biology HESI A2 Practice Exam Questions
Question 1 of 5
Duchenne muscular dystrophy is a recessive sex-linked trait carried on the X chromosome. In an example of an unaffected father and a female carrier who have two daughters and two sons, which is the predicted outcome?
Correct Answer: C
Rationale: Duchenne muscular dystrophy is a recessive sex-linked trait carried on the X chromosome. Since the father is unaffected and does not carry the disease, he must have a normal X chromosome. The mother is a carrier, which means she has one normal X chromosome and one X chromosome with the disease allele. The daughters will inherit one X chromosome from each parent; one would be normal, and the other has a chance of carrying the disease allele. So, there is a 50% chance that one daughter may have the disease, as she could inherit the X chromosome with the disease allele. The sons will inherit the Y chromosome from the father and the X chromosome from the mother, so they will not be affected by the disease.
Therefore, the predicted outcome is that one daughter may have the disease, while the sons will not carry the disease. This rules out choices A, B, and D.
Question 2 of 5
Which organism reproduces via spore formation?
Correct Answer: A
Rationale: The correct answer is A, Shelf fungus. Shelf fungus reproduces via spore formation. Spores are tiny, reproductive cells that are released into the environment to be carried by air or water, allowing the fungus to spread and reproduce. The other choices are incorrect because Lemon tree reproduces via seeds, Smallmouth bass reproduce sexually through the fertilization of eggs by sperm, and Staphylococcus bacteria reproduce by binary fission, dividing into two identical daughter cells.
Question 3 of 5
How should a researcher test the hypothesis that a particular species of bird vocalizes most in the hours around dawn?
Correct Answer: C
Rationale: Observing a flock of the birds in the wild and recording them in predawn and postdawn hours every day for six months would be the best way to test the hypothesis that a particular species of bird vocalizes most in the hours around dawn. This method allows for consistent monitoring of the birds during specific times of interest over an extended period, providing a comprehensive dataset to accurately analyze the vocalization patterns. Options A and B do not focus specifically on dawn hours, making them less suitable for testing the hypothesis. Option D introduces a comparison with other species, which is unnecessary and distracts from the main objective of studying the vocalization pattern of the particular bird species around dawn.
Question 4 of 5
Which type of sugar is a disaccharide?
Correct Answer: A
Rationale: The correct answer is A, Sucrose. Sucrose is a disaccharide composed of one molecule of glucose and one molecule of fructose. When glucose and fructose combine, they form sucrose.
Choice B, Fructose, is a monosaccharide, not a disaccharide.
Choice C, Glucose, is also a monosaccharide, not a disaccharide.
Choice D, Galactose, is another monosaccharide and not a disaccharide.
Question 5 of 5
Humans, or Homo sapiens, are part of the family ___________.
Correct Answer: B
Rationale: Humans, or Homo sapiens, are part of the family Hominidae, which includes great apes such as gorillas, chimpanzees, and orangutans. This family belongs to the order Primates within the class Mammalia.
Choice A (Animalia) refers to the animal kingdom, not the family of humans.
Choice C (Mammalia) is the class to which the family Hominidae belongs, not the family itself.
Choice D (Chordata) is the phylum to which humans and other animals with a notochord belong, not the specific family.