SB9

Question 1

Organism

Answer 1

A single living individual

Question 2

Population

Answer 2

All the organisms of the same species in an area

Question 3

Community

Answer 3

All the populations in an an era

Question 4

Ecosystem

Answer 4

All the the living organisms and the non living components in an area

Question 5

Living factors that affect distribution

Answer 5

Prey
Predator
Competitor

Question 6

Non-living factors that affect distribution

Answer 6

Light
Temperature
Rainfall
Oxygen levels in water
Pollution

Question 7

Competition

Answer 7

Organisms need a supply of materials from their surroundings so they can survive and reproduce. This means there is competition between organisms for materials that are in limited supply

Question 8

Parasitism

Answer 8

A parasite feeds on another organism whilst they are living together. This harms the host but benefits the parasite (e.g tapeworm and human)

Question 9

Mutualism

Answer 9

When two organisms live closely together in a way that benefits from the both they are called mutualists (e.g oxpecker and rhino)

Question 10

Quadrats

Answer 10

Square frames which we use to take samples of areas

Question 11

Number of organisms in whole area=

Answer 11

Number of organisms in one quadrant * (total area/area of one quadrant)

Question 12

Belt transects

Answer 12

The affect of abiotic factor and biotic factors on where organisms live can be studies using quadrats placed along a belt transect

Question 13

Trophies levels

Answer 13

The feeding levels in a food chain or food web

Question 14

Fish farming

Answer 14

Involves growing one kind of fish in an area. The fish are fed and the waste they produce is removed from their tanks

Question 15

Eval of fish farming

Answer 15

:) Fish farming reduces overfishing of wild fish

:( The waste from the tanks can pollute the local area, changing conditions, so that some local species die out

:( Diseases from the farmed fish can spread to wild fish and kill them

Question 16

Eutrophication

Answer 16

Fertilizers added to fields for crops may get into streams and rivers. This adds phosphates and nitrates to the water. Water plants and algae grow and then cover the water surface, blocking the light to deeper water. Deeper plants cannot get light so they die. Bacteria decomposes the dying plants, using oxygen from the water. There is no oxygen left for fish so they die.

Question 17

Non indigenous species

Answer 17

:) May provide food for native species

:( Out compete native species for food and other resources

:( May reproduce rapidly as they have no natural predators in the new area

Question 18

Pollution indicators species

Answer 18

Changes in the abundance of these species can show changes in the level of pollution

Question 19

Black spot fungus

Answer 19

Grows in clean air. Lack of black spot fungus on roses = air pollution

Question 20

Bloodworms

Answer 20

Indicate pollution in water as they can live with little oxygen

Question 21

How to prevent food decay

Answer 21

• Refrigerating food (Temp is too cold for most microorganisms to grow)
• Salting food (Causes water to move out of bacterial cells by osmosis)
• Packing food in nitrogen (No oxygen for microorganisms to grow)