1. Neurons, the functional units of the nervous system, belong to which tissue type?

A. Epithelial tissue
B. Connective tissue
C. Muscle tissue
D. Nervous tissue

Correct answer: D

Rationale: The correct answer is D: Nervous tissue. Neurons are specialized cells that transmit nerve impulses and are the primary components of the nervous system. Nervous tissue is made up of neurons and supporting cells called neuroglia. Neurons are responsible for processing and transmitting information throughout the body, making them a crucial part of the nervous system. Epithelial tissue (A) is primarily involved in covering and lining surfaces, connective tissue (B) supports and connects other tissues, and muscle tissue (C) is responsible for movement. Therefore, neurons belong to nervous tissue, which is specialized for communication and coordination within the body.

2. During exercise, oxygen is used to convert glucose into energy for muscles. This process is called:

A. Aerobic respiration
B. Anaerobic respiration
C. Glycolysis
D. Lactic acid fermentation

Correct answer: A

Rationale: The correct answer is 'A: Aerobic respiration.' During exercise, muscles require energy to function, and oxygen plays a crucial role in converting glucose into energy through aerobic respiration. This process occurs in the mitochondria of cells and involves the breakdown of glucose to produce ATP, the cell's energy currency. Aerobic respiration is efficient and produces a higher yield of ATP compared to anaerobic respiration or glycolysis alone. Anaerobic respiration (option B) and glycolysis (option C) are also involved in energy production but do not rely on oxygen. Lactic acid fermentation (option D) occurs when there is not enough oxygen available, leading to the accumulation of lactic acid. Therefore, the most appropriate answer is 'A: Aerobic respiration.'

3. Which sentence uses the semicolon correctly?

A. The play was long; however, it was very entertaining.
B. The guests arrived; Sarah greeted them at the door.
C. John likes apples; Mary prefers oranges.
D. He was tired; he went to bed early.

Correct answer: B

Rationale: Option B joins two independent clauses related to the same event.

4. Which term refers to the resistance of a liquid to flow?

A. Density
B. Viscosity
C. Surface tension
D. Boiling point

Correct answer: B

Rationale: Viscosity is the term that refers to the resistance of a liquid to flow. It is a measure of how thick or sticky a fluid is, and it determines how easily a liquid can flow. Density (A) is a measure of how much mass is contained in a given volume, surface tension (C) is the property of a liquid that allows it to resist an external force due to the cohesive nature of its molecules, and boiling point (D) is the temperature at which a liquid changes to a vapor.

5. What is the role of DNA in heredity?

A. Provides energy for the cell
B. Determines the structure and function of proteins
C. Stores and transmits genetic information
D. Controls cell division

Correct answer: C

Rationale: Rationale: DNA (deoxyribonucleic acid) is a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all living organisms. It stores genetic information in the form of a code made up of four chemical bases: adenine (A), thymine (T), cytosine (C), and guanine (G). This genetic information is passed down from parents to offspring and is responsible for determining an organism's traits and characteristics. DNA does not provide energy for the cell (option A), determine the structure and function of proteins (option B), or control cell division (option D).

6. Which of the following is the main organ responsible for absorbing nutrients?

A. Stomach
B. Small intestine
C. Large intestine
D. Pancreas

Correct answer: B

Rationale: Rationale: The small intestine is the main organ responsible for absorbing nutrients from the food we eat. It is where the majority of digestion and absorption of nutrients such as carbohydrates, proteins, fats, vitamins, and minerals occurs. The inner lining of the small intestine is covered in tiny finger-like projections called villi, which increase the surface area available for nutrient absorption. The stomach plays a role in breaking down food into smaller particles, but the actual absorption of nutrients primarily takes place in the small intestine. The large intestine mainly absorbs water and electrolytes, while the pancreas produces digestive enzymes and hormones but is not primarily responsible for absorbing nutrients.