ATI TEAS Practice Science Test

Correct Answer: B

Rationale: The correct answer is B: Cytoplasm. Pyruvate is an intermediate product of glycolysis, which occurs in the cytoplasm of the cell. The biochemist isolating pyruvate is working with the cytoplasm because that's where glycolysis takes place. Chloroplasts (A) are involved in photosynthesis, not glycolysis. Mitochondria (C) are responsible for aerobic respiration, where pyruvate is eventually transported to. The nucleus (D) contains the cell's genetic material and is not directly involved in pyruvate metabolism. Thus, the biochemist is likely isolating pyruvate from the cytoplasm.

Correct Answer: D

Rationale: The correct answer is D: Melanocyte-stimulating hormone. Melanocyte-stimulating hormone stimulates the melanocytes in the skin to produce melanin, the pigment responsible for skin color. This hormone darkens the skin by increasing melanin production. A: Follicle-stimulating hormone is involved in reproductive functions, not skin color changes. B: Growth-stimulating hormone primarily affects growth and development, not skin color. C: Thyroid-stimulating hormone regulates thyroid function, not skin color.

Correct Answer: D

Rationale: The impaired posterior pituitary gland leads to decreased production of antidiuretic hormone (ADH), resulting in the inability to concentrate urine. This causes the patient to excrete large volumes of dilute urine. Thirst (choice A) is a symptom of diabetes insipidus, a condition related to ADH deficiency. Tiredness (choice B) and weight gain (choice C) are not directly associated with impaired posterior pituitary function. Thus, choice D, concentrated urine, is the correct symptom related to kidney function in this scenario.

Correct Answer: C

Rationale: The correct answer is C: Shaft. The shaft is the portion of the hair that is visible above the skin's surface and is not attached to the follicle. The bulb (A) is the base of the hair follicle where the hair root (B) is located and is attached to the follicle. The strand (D) refers to the entire hair structure, including the bulb, root, and shaft. Therefore, the shaft is the only part that is not physically connected to the follicle.

Correct Answer: A

Rationale: The correct answer is A: Adenine. Adenine forms a complementary base pair with cytosine through hydrogen bonding in DNA. This pairing is essential for maintaining the structure and stability of the DNA double helix. Adenine and cytosine form two hydrogen bonds between them. Choices B, C, and D are incorrect because cytosine does not bind with itself (B), guanine (C), or thymine (D) in DNA. Thymine pairs with adenine, while guanine pairs with cytosine. Therefore, the correct base that binds with cytosine is adenine.