Chapter 19 Population in Ecosytems

Question 1

Definition of community

Answer 1

All the different species that live in one area and interact with one another

Question 2

Definition of ecology

Answer 2

The study of inter relationship’s between organisms and their environment

Question 3

What are biotic and abiotic factors? + eg

Answer 3

Biotic - living features of an ecosystem e.g. predators disease
Abiotic - non living features of an ecosystem e.g light and temperature

Question 4

Definition of ecosystem

Answer 4

All the organisms found in one area, combined with non living aspects of their environment.

Question 5

Definition of habitat

Answer 5

The place where an organism lives

Question 6

Definition of a niche

Answer 6

The role of a species within its habitat, consisting of both its biotic and abiotic interactions.

Question 7

Definition of Carrying capacity

Answer 7

The maximum size of population an ecosystem can support

Question 8

Abiotic factors that affect population growth

Answer 8

• Temperature
• Light
• pH
• Water

Question 9

Definition of intraspecific

Answer 9

Competition between organisms of the same species

Question 10

Definition of interspecific

Answer 10

Competition between organisms of different species

Question 11

Resources organisms may compete for?

Answer 11

• food
• water
  -shelter
• minerals
• light
• mates

Question 12

Pattern of typical predator prey relationshp

Answer 12

• Prey is eaten by predator resulting in prey population decreasing and predator population increasing
• Fewer prey means more competition so predator population decreases
  -Fewer Predator means more prey live so cycle goes again

Question 13

Use of Quadrats

Answer 13

• For non motile organisms and can be placed along transect belt or grid coordinates

Question 14

How is mark- release - capture technique used for estimating population size?

Answer 14

• A sample of species is caught and then marked and released in same area they were caught
• After a while another sample is taken in same area and the number of marked organisms is counted

Question 15

Equation for Mark-release-capture technique

Answer 15

total no of individuals in first sample x no individual in second sample / number of marked individuals recaptures

Question 16

Why are ecosystems describes as Dynamic?

Answer 16

• Population constantly rise and fall
  -Any small change can have a large effect
• Biotic and abiotic factors may alter the ecosystem

Question 17

Definition of Primary succesion

Answer 17

Where an area previously devoid of life is colonised

Question 18

Process of primary succession

Answer 18

• pioneer ( Original) species can survive harsh conditions and colonise the area
• Change abiotic factors of their environment
• Overtime allows more complex organisms to survive

Question 19

Climax community

Answer 19

Final stage of succesion where ecosytem is stable and balanced. Reached when soil is rich enough to support large trees or shrubs and environment is no longer changing

Question 20

Conservation

Answer 20

The protection and management of species and habitats, in order to maintain biodiversity.

Question 21

Predation

Answer 21

The biotic condition that drives adaptations to avoid being eaten by predators.