Topic 7—C: Populations in Ecosystems-1. Ecosystems

Question 1

Definition of ecosystem

Answer 1

• an ecosystem is all the organisms living in a community plus all the non-living (abiotic) conditions in the area in which they live

Question 2

What do ecosystems include?

Answer 2

• biotic conditions
• abiotic conditions

Question 3

What are biotic conditions?

Answer 3

• the living features of an ecosystem
  E.g. presence of predators or food

Question 4

What are abiotic conditions?

Answer 4

• the non-living features of an ecosystem e.g. temperature and soil

Question 5

Definition of habitat

Answer 5

The place where an organism lives within a ecosystem

Question 6

Definition of niche

Answer 6

• a niche is the role of a species within its habit e.g. what it eats, where and when it feeds

Question 7

What does a niche a species occupies include?

Answer 7

• biotic interactions
• abiotic interactions

Question 8

Biotic interactions

Answer 8

E.g. the organisms it eats and those it’s eaten by

Question 9

Abiotic interactions

Answer 9

E.g. the temperature range an organissm can live in, the time of day when an organism is active

Question 10

How many speeches can a niche be occupied by?

Answer 10

1

Question 11

What happens if two species try to occupy the same niche?

Answer 11

They will compete with eachother
- one species will be more successful than the other until only one of the species is left

Question 12

What is an adaptation?

Answer 12

It’s a feature that members of a species have that increases their chance of survival and reproduction

Question 13

What can the features either be?

Answer 13

• physiological (processes inside their body)
• behavioural (the way an organisms acts)
• anatomical (structural features of there body)
  E.g. giraffes have long necks to help them reach vegetation that’s high up, this increases their chance of survival when food is scarce

Question 14

What are organisms with better adaptations more likely to do?

Answer 14

• they are more likely to survive, reproduce and pass on the advantageous alleles that determine these
  Adaptations
• this increases the frequency of these alleles in the population which means the adaptaions become more common (natural selection)

Question 15

What conditions are organisms adapted to?

Answer 15

• abiotic conditions (how much water is available)
• biotic conditions ( what predators there are) in their ecosystem

Question 16

Adaptations to abiotic conditions

Answer 16

• otters have webbed paws- this means they can both walk on land and swim effectively. This increases their chances of survival because they can live and hunt both on land and in water
• seals have a thick layer of blubber (fat)- this helps to keep them warm in the coldest seas. This increases their chances of survival because they can live in places where food is plentiful
  -Hedgehogs hibernate- they lower their rate of metabolism over winter. This increases their chance of survival because they can conserve energy during the coldest months

Question 17

Adaptations to biotic conditions

Answer 17

-Chimpanzees use twigs to fish termites out of termite mounds. This increases their chance of survival because it gives them access to another source of food
- Male frogs produce mating calls to attract females- this make sure they attract a mate of the same species. This increases their chance of reproduction by making successful mating more likely
- Some bacteria produce antibiotics- these kill other species of bacteria in the same area. This increases their chances of survival because there’s less competition for resources