Science (General)

Question 1

Total energy varies with time
True/False

Answer 1

False

Question 2

Which state of matter expands the most?

Answer 2

Gases

Question 3

Which state of matter conducts heat the best?

Answer 3

Solids

Question 4

What is the main heating process of an object placed above a heat source?

Answer 4

Convection

Question 5

What is the main heating process of an object placed near a heat source?

Answer 5

Radiation

Question 6

Which contraceptive method is the most effective in preventing STIs?

Answer 6

Condom

Question 7

How to determine whether a chemical reaction is neutralisation?

Answer 7

Only water and salt is formed

Question 8

What is the order of the food chain?

Answer 8

Producers ->Primary consumers -> Secondary consumers -> Tertiary consumers

Question 9

Describe osmosis

Answer 9

There is a net movement of water molecules from a region of higher water potential to a region of lower water potential via osmosis down a water potential gradient

Question 10

Black VS White

Answer 10

Black is a good absorber/emitter of infrared radiation (increases rate of heat loss)
White is a poor absorber/emitter of infrared radiation (reduces rate of heat loss)

Question 11

What are the magnetic metals?

Answer 11

Iron, steel, cobalt, nickel

Question 12

Describe a fuse

Answer 12

Arranged in series with a circuit; Melts when there is excess current, preventing the circuit from overheating

Question 13

Describe a circuit breaker

Answer 13

A circuit breaker has many individual switches. the switches are connected to different appliances. When the current flow is too large, the switch linked to the appliance trips and cuts off the circuit

Question 14

When is a woman most fertile?

Answer 14

day 9 to 15

Question 15

How do enzymes help in the digestion of food?

Answer 15

They speed up the rate of chemical digestion by breaking down large insoluble food molecules into small soluble molecules

Question 16

Explain how osmosis takes place

Answer 16

A solution of higher water potential passes through a partially permeable membrane to a solution of lower water potential down a water potential gradient

Question 17

Define pressure

Answer 17

The force per unit contact area

Question 18

Name a non reactive metal

Answer 18

gold/silver/copper

Question 19

Name all the chemical equations that take place in the digestive system

Answer 19

1. Proteins -> (protease) polypeptides
   Polypeptides ->(protease) amino acids
2. Starch ->(salivary amylase) maltose
3. Maltose -> (maltase) glucose
4. Fats-> (lipase) glycerol + fatty acids

Question 20

Describe fertilisation

Answer 20

A sperm cell from the male reproductive system is deposited into the female reproductive system where it fuses with and fertilises an egg cell in the oviduct

Question 21

State the functions of amino acids, simple sugars, fatty acids and glycerol

Answer 21

Amino acids -> grow and repair tissue
Simple sugars -> release energy during respiration
Fatty acids + glycerol -> make fats