SCIENCE PART 2 ( ADRE)

Science part 2

Here are 15 multiple-choice questions (MCQs) on various science topics along with short explanations for each:

1 **What is the chemical symbol for water?**

   - A) H2O

   - B) CO2

   - C) O2

   - D) H2

   - **Answer:** A) H2O

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2. **What type of macromolecule are enzymes?**

   - A) Carbohydrates

   - B) Lipids

   - C) Proteins

   - D) Nucleic acids

   - **Answer:** C) Proteins

   

3. **What is the powerhouse of the cell?**

   - A) Nucleus

   - B) Mitochondria

   - C) Ribosome

   - D) Golgi apparatus

   - **Answer:** B) Mitochondria

   - **Explanation:** Mitochondria generate most of the cell's supply of ATP, used as a source of chemical energy.

4. **Which element is the most abundant in the Earth's crust?**

   - A) Iron

   - B) Oxygen

   - C) Silicon

   - D) Aluminum

   - **Answer:** B) Oxygen

   - **Explanation:** Oxygen makes up about 46% of the Earth's crust by weight.

5**What is the study of fungi called?**

   - A) Botany

   - B) Zoology

   - C) Mycology

   - D) Virology

   - **Answer:** C) Mycology

   - **Explanation:** Mycology is the branch of biology concerned with the study of fungi.

6. **Which organ is primarily responsible for filtering blood in the human body?**

   - A) Liver

   - B) Heart

   - C) Kidneys

   - D) Lungs

   - **Answer:** C) Kidneys

   - **Explanation:** The kidneys filter waste products from the blood and excrete them in urine.

7**What is the main function of red blood cells?**

    - A) Fight infection

    - B) Carry oxygen

    - C) Clot blood

    - D) Produce hormones

    - **Answer:** B) Carry oxygen

    - **Explanation:** Red blood cells contain hemoglobin, which binds to oxygen and transports it to tissues.

8. **Which vitamin is produced when the skin is exposed to sunlight?**

    - A) Vitamin A

    - B) Vitamin B

    - C) Vitamin C

    - D) Vitamin D

    - **Answer:** D) Vitamin D

    - **Explanation:** Vitamin D is synthesized by the skin upon exposure to ultraviolet B rays from the sun.

9. **What is the smallest unit of matter?**

    - A) Molecule

    - B) Atom

    - C) Electron

    - D) Neutron

    - **Answer:** B) Atom

    - **Explanation:** Atoms are the basic units of matter and the defining structure of elements.

10. **What is the hardest natural substance on Earth?**

    - A) Gold

    - B) Iron

    - C) Diamond

    - D) Quartz

    - **Answer:** C) Diamond

    - **Explanation:** Diamonds are composed of carbon atoms in a crystal structure that makes them extremely hard.

11*Which area of the brain regulates coordination and balance?

    - A) Cerebrum

    - B) Cerebellum

    - C) Medulla

    - D) Hypothalamus

    - **Answer:** B) Cerebellum

    - **Explanation:** The cerebellum is responsible for coordinating voluntary movements and maintaining balance and posture.

12. **Which of the following is not a renewable resource?**

    - A) Solar energy

    - B) Wind energy

    - C) Fossil fuels

    - D) Hydropower

    - **Answer:** C) Fossil fuels

    - **Explanation:** Fossil fuels are non-renewable because they take millions of years to form.

13. **What is the boiling point of water at standard atmospheric pressure?**

    - A) 50°C

    - B) 75°C

    - C) 100°C

    - D) 150°C

    - **Answer:** C) 100°C

    - **Explanation:** Water boils at 100°C (212°F) at standard atmospheric pressure (1 atmosphere).

14. **Which gas is essential for human respiration?**

    - A) Nitrogen

    - B) Carbon dioxide

    - C) Oxygen

    - D) Helium

    - **Answer:** C) Oxygen

    - **Explanation:** Oxygen is essential for the process of respiration, where cells use it to produce energy.

15 **What is the main element found in organic compounds?**

    - A) Nitrogen

    - B) Carbon

    - C) Hydrogen

    - D) Oxygen

    - **Answer:** B) Carbon

    - **Explanation:** Carbon is the key element in organic compounds, forming the backbone of organic molecules.