ATI TEAS Practice Science Test

Correct Answer: C

Rationale: The correct answer is C: Inverse correlation. Negative variation refers to a situation where one variable increases while the other decreases, showing an inverse relationship. This is different from non-correlation (A), which implies no relationship between variables. Direct correlation (B) indicates both variables moving in the same direction, while positive correlation (D) implies both variables increasing together. Therefore, C is the only choice that accurately represents negative variation.

Correct Answer: A

Rationale: During Prophase I of meiosis, chiasmata structures form as homologous chromosomes exchange genetic material through crossing over. This occurs after homologous chromosomes pair up during synapsis. Chiasmata play a crucial role in genetic diversity. In contrast, Prophase II is focused on preparing the cells for division, and chiasmata formation does not occur during this phase. Metaphase I is characterized by the alignment of homologous chromosomes at the metaphase plate, while Metaphase II involves the alignment of sister chromatids. Therefore, the correct answer is A: Prophase I, as it is the specific phase where chiasmata formation takes place.

Correct Answer: B

Rationale: The correct answer is B because urine is formed in the kidney during the process of fluid filling the collecting duct. This is where the final concentration and composition of urine are regulated. Before reaching the collecting duct, the initial filtration of blood occurs in the glomerulus (eliminating options C) and the fluid does not become urine until it has passed through the collecting duct (eliminating options A and D). So, the correct sequence is filtration in the glomerulus, reabsorption and secretion in the tubules, and final urine formation in the collecting duct.

Correct Answer: C

Rationale: The correct answer is C: Flexor. Flexor muscles are responsible for bending a joint by decreasing the angle between the bones they act upon. They contract to bring two body parts closer together. Cardiac muscles (A) are found in the heart and control its pumping action. Extension (B) refers to the straightening of a joint, not bending. Smooth muscles (D) are found in various organs and are not directly involved in joint movement. Therefore, the flexor muscle (C) is the correct choice for causing a joint to bend.

Correct Answer: C

Rationale: The correct answer is C: Epithelial cells. Epithelial cells are found in the hair bulb and are responsible for hair growth because they undergo rapid cell division and differentiation to form the hair shaft. Basal cells (choice A) are a type of epithelial cell found in the skin, but they mainly function in the regeneration of the epidermis. Epidermal cells (choice B) refer to the outer layer of the skin and do not play a direct role in hair growth. Merkel cells (choice D) are specialized touch receptors found in the skin, but they are not involved in hair growth. In summary, epithelial cells in the hair bulb are specifically designed for hair growth through their rapid division and differentiation process.