Science 3

Question 1

What is photosynthesis and where does it occur?

Answer 1

Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. It occurs in the chloroplasts of plant cells.

Question 2

Define the term ‘ecosystem’.

Answer 2

An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system.

Question 3

What are the three states of matter?

Answer 3

The three states of matter are solid, liquid, and gas.

Question 4

What is the difference between speed and velocity?

Answer 4

Speed is the rate at which an object covers distance, while velocity is speed in a given direction.

Question 5

What is a chemical reaction?

Answer 5

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.

Question 6

Explain the function of the respiratory system.

Answer 6

The respiratory system is responsible for taking in oxygen and expelling carbon dioxide. The primary organs of the respiratory system are the lungs.

Question 7

What is the Law of Conservation of Mass?

Answer 7

The Law of Conservation of Mass states that mass is neither created nor destroyed in a chemical reaction.

Question 8

How do plants reproduce?

Answer 8

Plants reproduce in a variety of ways, most commonly by producing seeds, but also through methods like spores and vegetative reproduction.

Question 9

What is the greenhouse effect?

Answer 9

The greenhouse effect is the process by which radiation from a planet’s atmosphere warms the planet’s surface to a temperature above what it would be without this atmosphere.

Question 10

Define an acid and a base.

Answer 10

An acid is a substance that donates hydrogen ions. A base is a substance that accepts hydrogen ions or donates hydroxide ions.

Question 11

What are the basic principles of genetics?

Answer 11

Basic principles of genetics include the understanding of genes, chromosomes, and how traits are passed from parents to offspring.

Question 12

Explain the role of enzymes in the human body.

Answer 12

Enzymes are proteins that act as catalysts in the human body, speeding up chemical reactions that are necessary for life.

Question 13

What is a renewable energy source?

Answer 13

A renewable energy source is one that is replenished naturally on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat.

Question 14

Describe the process of evaporation.

Answer 14

Evaporation is the process by which water changes from a liquid to a vapor or gas.

Question 15

What are the different layers of the Earth?

Answer 15

The Earth’s layers include the crust, the mantle, the outer core, and the inner core.

Question 16

What is the electromagnetic spectrum?

Answer 16

The electromagnetic spectrum is the range of all types of electromagnetic radiation, which includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Question 17

Explain the concept of a food chain.

Answer 17

A food chain shows the linear flow of energy and nutrients from one organism to another in an ecosystem.

Question 18

How do magnets work?

Answer 18

Magnets work due to the motion of electric charges. Every magnet has a north and a south pole.

Question 19

What are the different types of chemical bonds?

Answer 19

The different types of chemical bonds include ionic bonds, covalent bonds, and metallic bonds.

Question 20

Describe how a rainbow is formed.

Answer 20

A rainbow is formed when light is refracted, or bent, and then split into various colors as it passes through water droplets in the atmosphere.

Question 21

What is the role of platelets in blood?

Answer 21

Platelets are a component of blood whose function is to react to bleeding from blood vessel injury by clumping, thereby initiating a blood clot.

Question 22

How does the human nervous system function?

Answer 22

The human nervous system functions as the body’s control system and communication network. It consists of the brain, spinal cord, and a complex network of neurons.

Question 23

What causes earthquakes?

Answer 23

Earthquakes are caused by the sudden release of energy in the Earth’s crust that creates seismic waves, often due to tectonic plate movements.

Question 24

Explain the concept of thermal energy.

Answer 24

Thermal energy is the internal energy of an object due to the kinetic energy of its atoms or molecules.

Question 25

How do vaccines work against viruses?

Answer 25

Vaccines work against viruses by stimulating the immune system to produce an immune response, including the production of antibodies, which provides acquired immunity to specific infections.