Practice TEAS Science Test

Correct Answer: B

Rationale: The correct answer is B: To absorb water and form feces. The large intestine mainly functions to absorb water from the indigestible food residue and solidify it into feces before excretion. This process helps in maintaining the body's fluid balance and preventing dehydration. Why the other choices are incorrect: A: The absorption of proteins primarily occurs in the small intestine, not the large intestine. C: Enzymes for digestion are produced in the pancreas and small intestine, not in the large intestine. D: Fat storage is mainly regulated by adipose tissue throughout the body, not the large intestine.

Correct Answer: B

Rationale: The correct answer is B: Alveoli. Alveoli are tiny air sacs in the lungs where gas exchange occurs. Oxygen from the air we breathe passes into the blood vessels surrounding the alveoli, while carbon dioxide from the blood moves into the alveoli to be exhaled. The other choices are incorrect because: A: Trachea is the windpipe that carries air to and from the lungs, but gas exchange does not occur there. C: Bronchioles are small air passages that branch off the bronchi, leading air to the alveoli, but they are not the site of gas exchange. D: Diaphragm is a muscle that helps with breathing by expanding and contracting the chest cavity, but it is not directly involved in gas exchange.

Correct Answer: B

Rationale: The correct answer is B: Vitamin D. When skin is exposed to sunlight, it triggers the production of Vitamin D in the body. Sunlight activates a form of cholesterol in the skin, which then converts to Vitamin D through a series of chemical reactions. Vitamin A (Choice A) is not produced by sunlight but is found in foods like carrots. Vitamin K (Choice C) is involved in blood clotting and bone health but is not produced by sunlight. Vitamin E (Choice D) is an antioxidant found in foods like nuts and seeds, not produced through sun exposure.

Correct Answer: D

Rationale: The correct answer is D: Recessive Inheritance. Mendelian inheritance follows the principles proposed by Gregor Mendel, where traits are determined by pairs of genes, with one being dominant and the other recessive. In recessive inheritance, an individual must inherit two copies of the recessive allele to exhibit the trait. This type of inheritance follows Mendel's laws of segregation and independent assortment. In contrast, incomplete dominance (A) shows blending of traits, polygenic alleles (B) involve multiple genes contributing to a single trait, and combination inheritance (C) is not a recognized term in Mendelian genetics.

Correct Answer: A

Rationale: The correct answer is A: Ectoderm. During embryonic development, the nervous system originates from the ectoderm layer. The neural plate forms from the ectoderm, which further develops into the neural tube and neural crest cells, giving rise to the brain, spinal cord, and peripheral nervous system. The other choices, B: Endoderm, C: Gastroderm, and D: Mesoderm, do not give rise to the nervous system. Endoderm forms the innermost layer of organs like the gut, Gastroderm is not a recognized germ layer, and Mesoderm gives rise to structures like muscles, bones, and connective tissues, not the nervous system.