1. 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.

2. Elements tend to gain or lose electrons to achieve stable electron configurations like those of noble gases. Their group number often indicates the number of electrons gained/lost and the resulting ionic charge, providing a good starting point for prediction.

A. Ionic bonds involve electron sharing, while metallic bonds involve electron transfer
B. Ionic bonds are weak and directional, while metallic bonds are strong and non-directional
C. Ionic bonds exist between metals and non-metals, while metallic bonds exist only between metals
D. Ionic bonds form discrete molecules, while metallic bonds form extended structures

Correct answer: D

Rationale: Ionic bonds involve complete electron transfer between atoms, creating strong, non-directional electrostatic attraction. Metallic bonds involve a delocalized "sea" of electrons shared across all metal atoms, resulting in a strong, extended structure.

3. Which of the following is a weak acid commonly found in citrus fruits?

A. Sulfuric acid (HÃ¢â€šâ€šSOÃ¢â€šâ€ž)
B. Hydrochloric acid (HCl)
C. Citric acid
D. Nitric acid (HNOÃ¢â€šÆ’)

Correct answer: c

Rationale: Citric acid is a weak acid commonly found in citrus fruits. The other choices are strong acids.

4. Discern the INCORRECT function of the liver.

A. Bile production, aiding digestion.
B. Blood protein synthesis, such as albumin.
C. Glucose storage for energy regulation.
D. Filtration of waste products from the blood.

Correct answer: D

Rationale: Rationale: A) Correct - The liver produces bile, which aids in the digestion and absorption of fats in the small intestine. B) Correct - The liver is responsible for synthesizing blood proteins, including albumin, which helps maintain osmotic pressure in the blood. C) Correct - The liver stores glucose in the form of glycogen and helps regulate blood sugar levels by releasing glucose when needed. D) Incorrect - The liver does not filter waste products from the blood. Instead, the kidneys are responsible for filtering waste products from the blood and excreting them in the form of urine.

5. What is an example of a fibrous protein?

A. Insulin
B. Keratin
C. Hemoglobin
D. Collagen

Correct answer: D

Rationale: Rationale: A) Insulin is a hormone, not a fibrous protein. Insulin is produced in the pancreas and is involved in regulating blood sugar levels. B) Keratin is a fibrous structural protein found in hair, nails, and the outer layer of skin. It provides strength and protection. C) Hemoglobin is a globular protein found in red blood cells that is responsible for carrying oxygen from the lungs to the rest of the body. It is not a fibrous protein. D) Collagen is a fibrous protein that is the main component of connective tissues such as tendons, ligaments, and skin. It provides strength and structure to these tissues.

6. 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.