Ch19 Populations in ecosystems

Question 1

Species

Answer 1

1. similair observable characteristics
2. reproduce to produce fertile offspring

Question 2

Niche

Answer 2

1. the role of a species in a community
2. the conditions and resources required for organisms to survive and reproduce

Question 3

Succession

Answer 3

1. Colonisation by pioneer species
2. change in environment e.g. increase in nutrients/humus
3. enables other species to survive
4. change in biodiversity
5. increase in number of species
6. stability increases- less hostile
7. climax community

Question 4

Climax community

Answer 4

1. most stable
   2.

Question 5

Interspecific competition

Answer 5

competition between organisms of different species

Question 6

Intraspecific competition

Answer 6

competition between organisms of the same species

Question 7

abiotic factors

Answer 7

1. temperature
2. light
3. soil pH
4. water humidity

Question 8

Population

Answer 8

organisms of one species living in one area

Question 9

Community

Answer 9

organisms of all species living in one area

Question 10

mark-recapture critera

Answer 10

1. no immigration
2. no reproduction
3. large sample
4. marking doesn’t influence behaviour

Question 11

mark-recapture method

Answer 11

1. collect sample
2. mark the animal using non-toxic substance
3. leave sufficient time for animal to randomly distribute
4. recapture second sample
5. 1st x 2nd / marked in 2nd

Question 12

ecosystem

Answer 12

self-supporting system
community interacts with abiotic factors

Question 13

Reason for mean average

Answer 13

1. increase reliability of measurements
2. able to identify anomalies
3. repeatable results- less likely to be due to personal error

Question 14

predation

Answer 14

1. predator eat prey, reducing population
2. predators competition increase with reduced food source
3. weaker individuals unable to survive and reproduce(competitive exclusion principle)
4. predator population reduced
5. fewer prey are eaten so more survive and reproduce
6. prey population increase
7. predators have more prey available so survive and reproduce
8. predator population increases

Question 15

quadrat method

Answer 15

1. Split area in grid- numbering each square
2. Generate random numbers by drawing from a hat
3. count abundance of species in quadrat
4. record results from minimum of 20 squares

Question 16

Substance for mark-recapture

Answer 16

1. non-toxic
2. doesn’t make highly visible to predator

Question 17

abundance

Answer 17

number of individuals of a species in a given space

Question 18

Climax community

Answer 18

1. out-competes species
2. more complex food-webs
3. increased biodiversity
4. greater variety of niches
5. stable equilibirum