**Question:** What is the powerhouse of the cell?
A) Ribosome
B) Mitochondria
C) Nucleus
D) Golgi apparatus
**Answer:** B) Mitochondria
**Explanation:**
- Mitochondria are known as the powerhouse of the cell because they generate the majority of the cell's supply of adenosine triphosphate (ATP), which is used as a source of chemical energy.
- ATP is crucial for various cellular processes, including metabolism, growth, and cell division.
- The other options (A) Ribosome, (C) Nucleus, and (D) Golgi apparatus have different functions in the cell: ribosomes are involved in protein synthesis, the nucleus houses the cell's genetic material, and the Golgi apparatus processes and packages proteins.
**Question:** What is the largest organ in the human body?
A) Brain
B) Liver
C) Skin
D) Lungs
**Answer:** C) Skin
**Explanation:**
- The skin is considered the largest organ of the human body by surface area and weight.
- It serves multiple functions, including protection against pathogens, regulation of body temperature, sensation (touch, temperature, pain), and synthesis of vitamin D.
- The other options (A) Brain, (B) Liver, and (D) Lungs are important organs but are not as large as the skin.
**Question:** Which blood vessels carry blood away from the heart?
A) Arteries
B) Veins
C) Capillaries
D) Venules
**Answer:** A) Arteries
**Explanation:**
- Arteries are blood vessels that carry oxygen-rich blood away from the heart to various parts of the body.
- They have thick, muscular walls that help withstand the pressure of blood pumped by the heart.
- Veins (option B) carry blood back to the heart, capillaries (option C) are tiny vessels where oxygen and nutrients are exchanged with tissues, and venules (option D) are small veins that collect blood from capillaries.
**Question:** What is the function of the kidneys in the human body?
A) Digestion
B) Filtration of blood
C) Regulation of body temperature
D) Production of hormones
**Answer:** B) Filtration of blood
**Explanation:**
- The kidneys are vital organs that filter blood to remove waste products and excess substances (such as salts and water).
- They help maintain the body's balance of electrolytes, regulate blood pressure, produce red blood cells, and activate vitamin D.
- Digestion (option A) primarily occurs in the gastrointestinal tract, regulation of body temperature (option C) involves mechanisms like sweating and shivering, and production of hormones (option D) can involve various glands like the endocrine system.