Practice Science TEAS Test

Correct Answer: B

Rationale: The correct answer is B: Retina. The retina is a layer of light-sensitive cells located at the back of the eye that detects light and converts it into signals for the brain through the optic nerve. The iris (A) controls the amount of light entering the eye, the lens (C) helps to focus light onto the retina, and the pupil (D) regulates the amount of light entering the eye, but they do not convert light into signals for the brain like the retina does.

Correct Answer: A

Rationale: The correct answer is A: Bicarbonate. CO2 is primarily transported in the blood as bicarbonate ions. This process involves carbonic anhydrase converting CO2 into carbonic acid, which then dissociates into bicarbonate and hydrogen ions. Bicarbonate is the main form in which CO2 is transported from tissues to the lungs for elimination. Choice B, carbamino compounds, refers to CO2 bound to amino groups in hemoglobin, but this method is a minor mode of CO2 transport. Choice C, None of these, is incorrect as bicarbonate is indeed the primary mode of CO2 transport. Choice D, Plasma, is incorrect as CO2 is not directly transported in the blood as plasma but rather in the form of bicarbonate ions.

Correct Answer: B

Rationale: The correct answer is B: Malaria. Malaria is caused by a protozoan parasite called Plasmodium, which is transmitted through the bite of infected mosquitoes. Protozoan parasites are single-celled organisms that can cause various infectious diseases in humans. Measles (A), mumps (C), and mononucleosis (D) are caused by viruses, not protozoan parasites. Viruses are different from protozoa in terms of structure, replication, and mode of infection. Therefore, the correct choice is B as it aligns with the characteristic of being caused by a protozoan parasite.

Correct Answer: D

Rationale: The correct answer is D: Thyroid. The thyroid gland produces hormones such as thyroxine and triiodothyronine, which play a crucial role in regulating metabolism. These hormones control the body's metabolic rate, affecting processes like energy production and consumption. The thymus (A) is responsible for immune function, the pituitary gland (B) regulates various hormones but not specifically metabolism, and the pancreas (C) produces insulin and glucagon to regulate blood sugar levels, not metabolism directly. In summary, the thyroid gland is the correct choice as it specifically regulates metabolism through thyroid hormones.

Correct Answer: A

Rationale: The correct answer is A: B6. Vitamin B6, also known as pyridoxine, is not synthesized in the large intestine. It is primarily absorbed in the small intestine. Biotin, Pantothenic acid, and Vitamin K are all synthesized in the large intestine. Biotin and Pantothenic acid are produced by gut bacteria, while Vitamin K is synthesized by the intestinal flora. Therefore, the correct answer is A because B6 is not synthesized in the large intestine, unlike the other options.