1. Negative feedback mechanisms are crucial in the endocrine system to:

A. Increase hormone production continuously
B. Maintain hormone levels within a specific range
C. Cause a constant release of hormones
D. Disrupt communication between glands

Correct answer: B

Rationale: The correct answer is B: 'Maintain hormone levels within a specific range.' Negative feedback mechanisms in the endocrine system are essential for regulating hormone levels. These mechanisms work to counteract any deviations from the set point, ensuring that hormone levels remain balanced and within the optimal range for proper physiological function. Continuous hormone production (A) or constant release of hormones (C) would lead to imbalances and potential harm to the body. Disrupting communication between glands (D) would hinder the coordination necessary for maintaining homeostasis. Therefore, option B is the best choice as it highlights the critical role of negative feedback in keeping hormone levels stable and regulated.

2. Classifications of human tissues exclude:

A. Epithelial tissue
B. Nervous tissue
C. Adipose tissue (a specialized form of connective tissue)
D. Bony tissue

Correct answer: D

Rationale: The correct answer is D: 'Bony tissue.' Classifications of human tissues typically include four main types: epithelial, connective, muscular, and nervous tissue. Bony tissue, also known as osseous tissue, is a specialized form of connective tissue that forms bones in the skeletal system. While bony tissue is an essential component of the human body, it is not typically categorized separately as a distinct tissue type in general tissue classifications. Therefore, it is the exception from the list provided in the question, making it the correct answer.

3. A decorative box has a rectangular base (20cm by 15cm) and a hemispherical top with the same diameter as the base. What is the total surface area of the box (excluding the base)?

A. 825 sq cm
B. 1075 sq cm
C. 1325 sq cm
D. 1575 sq cm

Correct answer: C

Rationale: Calculate the surface area of the lateral sides and the hemisphere, then add them up.

4. Which of the following is the primary function of the ovaries in the female reproductive system?

A. Transport sperm to the uterus
B. Produce milk for feeding offspring
C. Produce eggs (ova)
D. Regulate urination

Correct answer: C

Rationale: The primary function of the ovaries in the female reproductive system is to produce eggs (ova). Ovaries are responsible for the production and release of eggs during the menstrual cycle, which can be fertilized by sperm to form a zygote. This process is essential for reproduction and the continuation of the species. Options A, B, and D are incorrect as transporting sperm to the uterus is the role of the fallopian tubes, producing milk for feeding offspring is the function of the mammary glands, and regulating urination is controlled by the bladder and associated muscles, not the ovaries.

5. In which direction do the particles of the medium move in a transverse wave?

A. Perpendicular to the direction of wave travel
B. Parallel to the direction of wave travel
C. In a circular motion
D. Opposite to the direction of wave travel

Correct answer: a

Rationale: In a transverse wave, particle displacement occurs perpendicular to the direction of wave travel.

6. Which of the following is the main organ responsible for regulating sleep?

A. Thalamus
B. Hypothalamus
C. Pituitary gland
D. Pineal gland

Correct answer: B

Rationale: Rationale: The hypothalamus is the main organ responsible for regulating sleep. It plays a crucial role in controlling the body's circadian rhythm, which is the internal clock that regulates the sleep-wake cycle. The hypothalamus receives input from the eyes about light and darkness, which helps in determining when it is time to sleep or wake up. It also regulates the production of melatonin by the pineal gland, which is a hormone that helps control sleep patterns. While the thalamus is involved in relaying sensory information to the brain, the pituitary gland is responsible for producing and releasing hormones, and the pineal gland produces melatonin under the control of the hypothalamus.