Which conditions would give the results shown in diagrams X and Y?

Correct Answer: C

Rationale: The correct answer is C because diagram X shows an increase in oxygen concentration over time, which indicates photosynthesis occurring. In photosynthesis, plants take in carbon dioxide and release oxygen. Therefore, the conditions of oxygen at 25°C and carbon dioxide at 25°C would support this process. Choices A, B, and D have incorrect combinations of temperature and gases that would not result in the observed increase in oxygen concentration in diagram X.

Correct Answer: D

Rationale: The correct answer is D: It is double-insulated. This is correct because double-insulated appliances have an extra layer of insulation for added safety, eliminating the need for a grounded connection. This feature protects users from electric shocks. Explanation for why the other choices are incorrect: A: It does not have a live connection - This is not necessarily true as appliances can have live connections depending on their design and function. B: It has two fuses - While some appliances may have fuses, the number of fuses does not determine the correctness of the statement about the appliance. C: It has two switches - The presence of two switches does not necessarily indicate the correctness of the statement about the appliance.

Correct Answer: D

Rationale: The correct answer is D: permissiveness. Permissiveness is when one hormone enables another hormone to fully exert its effects. The rationale is as follows: 1. Permissiveness allows a hormone to work effectively only when another hormone is present to "permit" its action. 2. Assertiveness (A) and antagonism (B) do not involve the requirement of another hormone for full effect. 3. Synergism (C) involves two hormones working together for a greater effect, but they can still exert some effect individually. In summary, permissiveness is the only option where a hormone cannot exhibit its full effect without the presence of another hormone.

Correct Answer: D

Rationale: Osteitis fibrosa cystica is caused by an increase in the parathyroid hormone (PTH). Elevated PTH levels lead to increased calcium release from bones, resulting in bone resorption and cyst formation. Other choices (A) calcitonin, (B) ADH, and (C) growth hormone do not directly impact calcium metabolism and bone resorption like PTH does.

Correct Answer: C

Rationale: The correct answer is C because the release of hormones by the parathyroid glands is actually controlled by the levels of calcium in the blood, not by the pituitary gland. A: True - Parathyroid glands are four small yellowish brown ovoid glands. B: True - They lie in relation to the posterior border of thyroid lobes. D: True - The hormone produced by the parathyroid glands, parathyroid hormone (PTH), controls blood calcium levels by stimulating the release of calcium from bones and increasing the absorption of calcium from the intestines.