TEAS 7 science practice questions

Correct Answer: B

Rationale: A goiter is a condition characterized by the abnormal enlargement of the thyroid gland. This enlargement can be caused by various factors such as iodine deficiency, thyroid nodules, inflammation, or other thyroid disorders. It is not associated with the overproduction of cortisol (Choice A), underproduction of parathyroid hormone (Choice C), or deficiency of growth hormone (Choice D). Therefore, the correct answer is B, excessive growth of the thyroid gland.

Correct Answer: D

Rationale: SOCl2 (thionyl chloride) is commonly used to convert primary alcohols to alkyl halides through an SN2 mechanism. Thionyl chloride reacts with the alcohol to form an alkyl chloride. HI (hydroiodic acid) is typically used to convert alcohols to alkyl iodides specifically, not alkyl halides in general. H2O (water) and NaOH (sodium hydroxide) are not reagents used for converting alcohols to alkyl halides. Therefore, the correct answer is SOCl2 as it facilitates the conversion of primary alcohols to alkyl halides, unlike the other options provided.

Correct Answer: D

Rationale: The primary function of the liver is to detoxify harmful substances in the body. While the liver does produce bile to aid in the digestion of fats, this is not its primary function. Bile is stored in the gallbladder and released into the small intestine for fat digestion. Storing energy in the form of glycogen is a function of the liver, but not its primary one. Glycogen serves as a reserve of glucose. Although the liver produces proteins that assist in blood clotting, such as fibrinogen and prothrombin, this is not its main function. These proteins play a crucial role in blood clotting to prevent excessive bleeding. Therefore, the primary role of the liver is to detoxify harmful substances by processing and removing toxins, drugs, alcohol, and other harmful substances from the bloodstream, thereby reducing their harmful effects.

Correct Answer: C

Rationale: Carboxylic acids contain the carboxyl functional group, which consists of a carbonyl group (C=O) and a hydroxyl group (-OH) attached to the same carbon atom. The carboxyl group is represented as -COOH in the molecular structure of carboxylic acids. Therefore, the correct functional group present in carboxylic acids is the carboxyl group, making option C the correct choice. Option A, 'Carbonyl,' is incorrect as it only refers to the C=O group without the -OH component present in carboxylic acids. Option B, 'Hydroxyl,' is incorrect as it only represents the -OH group without the carbonyl group. Option D, 'Aldehyde,' is incorrect as it refers to a different functional group with a carbonyl group attached to a hydrogen atom, not the carboxyl group found in carboxylic acids.

Correct Answer: A

Rationale: Phagocytes are a type of white blood cell that plays a crucial role in the immune system by engulfing and digesting foreign invaders such as bacteria, viruses, and other harmful substances. They are part of the body's innate immune response and are essential for protecting the body against infections. Lymphocytes, on the other hand, are another type of white blood cell involved in the adaptive immune response, producing antibodies, and coordinating immune responses. Platelets are cell fragments involved in blood clotting, while red blood cells are responsible for carrying oxygen to tissues. Therefore, the correct answer is Phagocytes (Choice A) because they are specifically tasked with attacking and destroying foreign invaders in the body, distinguishing them from the other choices which have different functions within the immune system.