Free BMST Science Questions and Answers 2 — Questions and Answers
Question 1: What is the basic unit of life?
- Cell (Correct answer)
- Atom
- Molecule
- Organ
Correct answer: Cell
The cell is the smallest structural and functional unit of all living organisms.
The cell is considered the basic unit of life because it is the smallest structure capable of performing all necessary life functions: metabolism, growth, reproduction, and response to stimuli. All living organisms are composed of one or more cells. Cell theory, established in the 1800s, states that all cells come from pre-existing cells.
Question 2: Which planet is closest to the Sun?
- Mercury (Correct answer)
- Venus
- Earth
- Mars
Correct answer: Mercury
Mercury is the innermost planet, orbiting at an average distance of 57.9 million km from the Sun.
Mercury is the closest planet to the Sun, orbiting at an average distance of about 57.9 million km (0.39 AU). The order of planets from the Sun is: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Despite being closest to the Sun, Mercury is not the hottest planet — Venus is, due to its thick greenhouse atmosphere.
Question 3: What gas do plants absorb from the atmosphere during photosynthesis?
- Carbon dioxide (Correct answer)
- Oxygen
- Nitrogen
- Hydrogen
Correct answer: Carbon dioxide
Plants absorb CO₂ and use it with water and sunlight to produce glucose and oxygen.
During photosynthesis, plants absorb carbon dioxide (CO₂) through tiny pores called stomata on their leaves. The overall equation is: 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂. Plants use CO₂ and water to produce glucose (food) and release oxygen as a byproduct. This is the reverse of cellular respiration.
Question 4: What is the chemical symbol for gold?
- Au (Correct answer)
- Go
- Gd
- Ag
Correct answer: Au
Au comes from the Latin word "aurum" meaning gold.
Gold's chemical symbol Au derives from the Latin word "aurum." Many elements have symbols from their Latin names: Au (gold/aurum), Ag (silver/argentum), Fe (iron/ferrum), Cu (copper/cuprum), Pb (lead/plumbum). Gd is gadolinium, and Ag is silver. Gold has atomic number 79 and is a noble metal known for its resistance to corrosion.
Question 5: What type of energy is stored in food?
- Chemical energy (Correct answer)
- Kinetic energy
- Nuclear energy
- Electrical energy
Correct answer: Chemical energy
Food contains chemical energy stored in molecular bonds, released during digestion and cellular respiration.
Chemical energy is the energy stored in the bonds of chemical compounds like carbohydrates, fats, and proteins in food. During digestion, these bonds are broken down, and the energy is converted to ATP through cellular respiration. This is the same type of energy stored in fuels like gasoline and batteries. It is a form of potential energy.
Question 6: What force keeps the planets in orbit around the Sun?
- Gravity (Correct answer)
- Magnetism
- Friction
- Nuclear force
Correct answer: Gravity
Gravitational attraction between the Sun and planets provides the centripetal force needed for orbital motion.
Gravity is the force of attraction between all objects with mass. The Sun's enormous mass creates a strong gravitational field that keeps planets in orbit. Newton's Law of Universal Gravitation states F = GMm/r², where the force depends on both masses and the distance between them. Without gravity, planets would travel in straight lines into space.
Free BMST Science Questions and Answers 2
What is the basic unit of life?