CAEC Life and Physical Sciences 3

Question 1

What is the role of DNA in living organisms?

Accepted Answer

To store and transmit genetic information that directs the growth and function of cells

Answer

To carry oxygen to cells

Answer

To produce energy through photosynthesis

Answer

To break down food in the digestive system

Question 2

What is the law of conservation of energy?

Accepted Answer

Energy cannot be created or destroyed; it can only change from one form to another

Answer

Energy can be created from nothing under the right conditions

Answer

Energy is always lost as heat in any process

Answer

The total energy of a system decreases over time

Question 3

What is the function of the circulatory system in the human body?

Accepted Answer

To transport blood, oxygen, and nutrients to cells and remove waste products

Answer

To break down food and absorb nutrients

Answer

To coordinate muscle movement

Answer

To produce hormones that regulate growth

Question 4

What is the difference between a renewable and a non-renewable energy source?

Accepted Answer

Renewable energy sources are replenished naturally over short periods; non-renewable sources take millions of years to form and can be depleted

Answer

Renewable energy is more expensive; non-renewable is cheaper

Answer

Renewable energy always comes from the sun; non-renewable comes from the earth

Answer

Renewable energy produces pollution; non-renewable does not

Question 5

What happens during photosynthesis?

Accepted Answer

Plants use sunlight, carbon dioxide, and water to produce glucose and oxygen

Answer

Plants break down sugar to release energy

Answer

Bacteria convert nitrogen in the air to soil nutrients

Answer

Animals convert oxygen and glucose into carbon dioxide and energy

Question 6

What is the pH scale used to measure?

Accepted Answer

The acidity or alkalinity of a solution, ranging from 0 (most acidic) to 14 (most alkaline)

Answer

The temperature of a liquid

Answer

The concentration of salt in water

Answer

The boiling point of a liquid