Ecosystems, Succession and Competition

Question 1

What are populations?

Answer 1

The total number of individuals of one species in a given area, at a given time.

Question 2

What are communities?

Answer 2

The different species living in the same area at the same time.

Question 3

What is an ecosystem?

Answer 3

All of the living and non living parts in an area and how they interact.

Question 4

What is a niche?

Answer 4

The area that an organism lives in and what it does there.

Question 5

What does biotic mean?
Give examples.

Answer 5

Living parts of an ecosystem.
Such as predators, pathogens, prey, mates etc

Question 6

What does abiotic mean?

Answer 6

Non living parts of ecosystem.
Such as soil pH, temperature, rainfall, space etc

Question 7

What is carrying capacity?

Answer 7

The total number of organisms that an area can support without causing environmental damage.

Question 8

What is intraspecific competition?

Answer 8

Individuals of the same species compete with each other for food and resources.

Question 9

What is interspecific competition?

Answer 9

Individuals of different species compete for resources.

Question 10

What are predators?

Answer 10

Animals that hunt and kill others.

Question 11

Describe the shape of a predator prey graph.

Answer 11

As prey populations rise, predator populations rise as there is more foot to support them. However, if predator population gets too high, there will not be enough prey to feed all, so some die. Therefore, predator populations fall.

Question 12

Why do 2 species never have the exact same niche?

Answer 12

They outcompete each other as there will not be enough resources to support both.

Question 13

What happens when niches of 2 species overlap?

Answer 13

Species compete with each other and over time, one will be more successful than the other, so they die out.

Question 14

What do food chains show?

Answer 14

Movement of energy through organisms.

Question 15

What is the competitive exclusion principle?

Answer 15

When populations of 2 species initially occupy the same niche, one species tries to avoid competition.

Question 16

What is a habitat?

Answer 16

The location that an organism lives in.

Question 17

Why do we use a logarithmic scale when plotting growth curves?

Answer 17

Population growth can be extremely rapid, for example, when measuring bacteria growth

Question 18

What is succession?

Answer 18

Ecological succession is the process of change in the species that make up an ecological community over time.

Question 19

In succession, how might the presence of new species in an area change the population size of existing species?

Answer 19

The environment may be less suitable for the old species, so they die out while new one colonises.

Question 20

In succession, how might a change in habitat benefit new species but damage old ones?

Answer 20

New ones may be better adapted, old ones may not be and therefore die out.

Question 21

What is primary succession?

Answer 21

Organisms colonise a lifeless habitat.

Question 22

What is secondary succession?

Answer 22

Organisms recolonise a devastated ecosystem, such as after a forest fire.

Question 23

What are pioneer species?

Answer 23

Species that first colonise an inhospitable environment.

Question 24

What is climax community?

Answer 24

Where the community established after succession remains stable for a long period of time.

Question 25

Give 3 examples of things that may emerge as a result of succession.

Answer 25

More complex food webs
Increased biomass
Greater number of habitats and niches
Abiotic environment hostility decreases

Question 26

What is conservation?

Answer 26

Where succession is prevented to protect habitats.