1. Which type of muscle is found in the walls of hollow organs, such as the stomach and intestines, and is responsible for involuntary contractions to propel substances through the organs?

A. Cardiac muscle
B. Smooth muscle
C. Skeletal muscle
D. Striated muscle

Correct answer: b

Rationale: The correct answer is B: Smooth muscle. Smooth muscle is found in the walls of hollow organs like the stomach and intestines. It is responsible for involuntary contractions to move substances through these organs. Unlike skeletal muscle (answer C) and cardiac muscle (answer A), smooth muscle is not under voluntary control. Striated muscle (answer D) is a term that refers to both skeletal and cardiac muscle due to their striped appearance under a microscope, but smooth muscle does not have this striped appearance.

2. The term "double circulation" in the cardiovascular system refers to

A. The separation of oxygenated and deoxygenated blood flow within the heart.
B. The regulation of blood pressure through vasoconstriction and vasodilation
C. The cyclic contraction and relaxation of the heart muscle.
D. The existence of two separate circulatory pathways, one for the lungs and one for the body.

Correct answer: D

Rationale: The term 'double circulation' in the cardiovascular system refers to the existence of two separate circulatory pathways, one for the lungs (pulmonary circulation) and one for the body (systemic circulation). In pulmonary circulation, deoxygenated blood is pumped from the heart to the lungs to pick up oxygen and release carbon dioxide. Then, oxygenated blood returns to the heart to be pumped out to the rest of the body in systemic circulation. This separation of oxygenated and deoxygenated blood flow in different pathways is what distinguishes the double circulation system. Therefore, option D is the correct answer as it accurately describes the concept of double circulation in the cardiovascular system.

3. What property of a wave determines the loudness of sound when heard by the human ear?

A. Frequency
B. Amplitude
C. Wavelength
D. Velocity

Correct answer: b

Rationale: The amplitude of a sound wave correlates with its perceived loudness by the human ear.

4. What are chromosomes made of?

A. DNA and RNA
B. DNA and proteins
C. Proteins and carbohydrates
D. DNA only

Correct answer: B

Rationale: Rationale: Chromosomes are structures found in the nucleus of cells that contain genetic material. They are made up of DNA (deoxyribonucleic acid), which carries the genetic information, and proteins that help in the organization and packaging of the DNA. While RNA is involved in various cellular processes, it is not a major component of chromosomes. Carbohydrates are not a significant component of chromosomes. Therefore, the most accurate answer is B) DNA and proteins.

5. What is the main function of the gallbladder?

A. To store and concentrate bile
B. To produce digestive enzymes
C. To absorb nutrients
D. To neutralize stomach acid

Correct answer: A

Rationale: Rationale: The gallbladder is a small organ located beneath the liver that plays a crucial role in the digestive system. Its main function is to store and concentrate bile, a digestive fluid produced by the liver. Bile is released from the gallbladder into the small intestine to help with the digestion and absorption of fats. The gallbladder acts as a reservoir for bile, allowing it to be released in a controlled manner when needed to aid in the digestion of fatty foods. Therefore, option A is the correct answer as it accurately describes the main function of the gallbladder.

6. What is the main function of the large intestine?

A. Break down food
B. Absorb water
C. Secrete digestive enzymes
D. Store waste

Correct answer: B

Rationale: The correct answer is B: "Absorb water." The main function of the large intestine is to absorb water and electrolytes from the undigested food material that passes through it. This helps in the formation of solid waste or feces, which is then stored in the rectum until it is eliminated from the body. Breaking down food primarily occurs in the small intestine, while the large intestine focuses on reabsorbing water to prevent dehydration. Secreting digestive enzymes is mainly done by the pancreas and liver, not the large intestine.