B15 Ecology

Question 1

Define habitat.

Answer 1

The part of an ecosystem where an organism lives.

Question 2

Define species.

Answer 2

This is a group of organisms that can breed together to produce fertile offspring.

Question 3

Define population.

Answer 3

This is the organisms of the same species that share a particular habitat.

Question 4

Define community.

Answer 4

This is made up of all the organisms that share a particular habitat.

Question 5

Define competition.

Answer 5

A word that describes the fact that organisms often need the same resources.

Question 6

Define interdependent.

Answer 6

A word that describes how organisms rely on and impact upon each other.

Question 7

Define a biotic factor.

Answer 7

Living things that can affect a population.

Question 8

Define an abiotic factor.

Answer 8

Non-living things that can affect a population.

Question 9

Give 3 examples of a biotic factor.

Answer 9

• Light intensity
• Temperature
• Moisture levels
• Soil pH / Mineral content
• Wind intensity
• Oxygen availability
• Carbon dioxide availability

Question 10

Give 3 examples of an abiotic factor.

Answer 10

• Food availability
• Pathogens / Parasites
• New predators
• Interspecific Competition

Question 11

Explain how light intensity can affect communities.

Answer 11

• Limits photosynthesis, affects distribution and growth of plants
• Breeding cycle of animals is linked to day-night cycle

Question 12

Explain how temperature can affect communities.

Answer 12

• Limits photosynthesis, affects distribution and growth of plants
• Small plants affects herbivores, less herbivores affect carnivores

Question 13

Explain how moisture levels can affect communities.

Answer 13

• Water is essential to life

- In deserts, there are no plants until it rains, animals move to these areas or starve

Question 14

Explain how the soil’s pH levels and mineral content can affect communities.

Answer 14

• Most organisms can’t survive without good soil, some exploit it to trap prey
• Low pH inhibits plant decay, so mineral ions aren’t released into the soil

Question 15

Explain how wind intensity can affect communities.

Answer 15

• Strong winds can change the shape of the landscape / trees

- Plants transpire quicker

Question 16

Explain how oxygen availability can affect communities.

Answer 16

• Most fish need dissolved oxygen to survive

- Some can survive with very low oxygen levels

Question 17

Explain how carbon dioxide availability can affect communities.

Answer 17

• Limits photosynthesis, affects distribution and growth of plants
• Affects distribution of organisms

Question 18

Explain how food availability can affect communities.

Answer 18

• Organisms can breed much easier with food

Question 19

Explain how new pathogens or parasites can affect communities.

Answer 19

• Organisms won’t have resistance / immunity to the new disease
• It can wipe out entire populations

Question 20

Explain how new predators can affect communities.

Answer 20

• Organisms may not be strong enough to fight back against predators

Question 21

Explain how interspecific competition can affect communities.

Answer 21

• A new species can take over an area, outcompeting the other organisms
• Their numbers can low enough that they can’t successfully breed

Question 22

What resources do animals compete for?

Answer 22

Territory
Food
Mates

Question 23

What resources do plants compete for?

Answer 23

Light
Water
Nutrients
Space to grow