1. he adrenal cortex produces a group of steroid hormones called corticosteroids. What is a MAJOR function of corticosteroids?

A. Regulate insulin sensitivity and blood sugar levels
B. Control blood pressure and electrolyte balance
C. Stimulate the immune system and inflammatory response
D. Promote growth and development during puberty

Correct answer: B

Rationale: The correct answer is B: 'Control blood pressure and electrolyte balance.' Corticosteroids, produced by the adrenal cortex, play a major role in regulating blood pressure and electrolyte balance in the body. These hormones, such as aldosterone, act on the kidneys to control the reabsorption of sodium and water, which in turn affects blood pressure and electrolyte levels. While corticosteroids can have effects on other physiological processes, their primary function is to regulate blood pressure and electrolyte balance, making option B the most appropriate choice in this context.

2. The constituents of an atomic nucleus consist of:

A. Electrons and protons only
B. Protons and neutrons only
C. Electrons, protons, and neutrons
D. None of the above

Correct answer: B

Rationale: The correct answer is B: "Protons and neutrons only." This is because the atomic nucleus is composed of protons, which carry a positive charge, and neutrons, which are neutral. Electrons are found outside the nucleus in electron shells. Protons and neutrons are collectively known as nucleons and are responsible for the mass of the atom. Electrons are much lighter and are involved in chemical reactions and bonding. Therefore, the constituents of an atomic nucleus are specifically protons and neutrons, making option B the correct choice.

3. Reactions requiring light energy to proceed are classified as:

A. Combustion reactions
B. Endothermic reactions
C. Photochemical reactions
D. Double displacement reactions

Correct answer: C

Rationale: The correct answer is C: "Photochemical reactions." Photochemical reactions are a type of chemical reaction that requires light energy to proceed. During a photochemical reaction, light energy is absorbed by a substance, leading to changes in its chemical structure or properties. This process is different from combustion reactions (A), which involve the rapid combination of a fuel with oxygen to release heat and light energy. Endothermic reactions (B) absorb heat energy, not light energy, to proceed. Double displacement reactions (D) involve the exchange of ions between reactants, but do not specifically require light energy to occur. Therefore, the most appropriate classification for reactions requiring light energy is photochemical reactions.

4. Delta waves, associated with deep sleep, exhibit what frequency range?

A. 0.5-4 Hz
B. 4-8 Hz
C. 8-13 Hz
D. 13-30 Hz

Correct answer: A

Rationale: Delta waves are slow brainwaves that are typically associated with deep sleep stages, such as stages 3 and 4 of non-REM sleep. These waves have a frequency range of 0.5-4 Hz, making option A the correct answer. During deep sleep, the brain slows down significantly, and delta waves are prominent on an electroencephalogram (EEG). The frequency range of 4-8 Hz corresponds to theta waves, which are more commonly observed during light sleep or drowsiness. Alpha waves fall within the 8-13 Hz range and are typically seen when an individual is awake but relaxed. Beta waves, ranging from 13-30 Hz, are associated with alertness and active thinking. Therefore, option A is the correct choice for delta waves, reflecting their slow frequency characteristic during deep sleep.

5. The feedback loop is a crucial concept in endocrine regulation. In a negative feedback loop, high levels of a hormone can:

A. Further stimulate the release of the same hormone
B. Inhibit the release of the hormone or its production
C. Have no effect on the hormone's regulation
D. Increase the need for another hormone entirely

Correct answer: B

Rationale: In a negative feedback loop, high levels of a hormone signal the body to stop producing more of that hormone in order to maintain homeostasis. This is a self-regulating mechanism to prevent excessive levels of the hormone. Option B is correct because in this scenario, the high levels of the hormone will inhibit its further release or production. This feedback loop helps ensure that hormone levels stay within a narrow range, preventing overstimulation or imbalance in the endocrine system. Options A, C, and D are incorrect as they do not align with the concept of negative feedback regulation in endocrine systems.

6. Nuclear fission is a process characterized by:

A. A heavy nucleus capturing a neutron and releasing energy
B. The fusion of two nuclei to form a heavier element
C. A lighter element emitting an alpha particle through radioactive decay
D. An electron being absorbed by the nucleus with the release of a gamma ray

Correct answer: A

Rationale: Nuclear fission is a process characterized by a heavy nucleus capturing a neutron and splitting into smaller nuclei, releasing a significant amount of energy in the form of heat and radiation. This differs from nuclear fusion, which involves the merging of two lighter nuclei to form a heavier element. The emission of an alpha particle by a lighter element is a form of radioactive decay, not fission. Absorption of an electron by the nucleus with the release of a gamma ray is not representative of fission reactions. Therefore, option A correctly describes the process of nuclear fission.