c4.1 populations and communities

Question 1

population

Answer 1

number of interacting groups of the same species living in a specific same area

Question 2

community

Answer 2

all of the interacting organisms of all species in an ecosystem

Question 3

what do all environments have

Answer 3

a finite carrying capacity

Question 4

sigmoid growth curve

Answer 4

1. fast growth
2. plateau

Question 5

why is there a fast growth at the start [2]

Answer 5

1. lack of competition
2. abundance of resources

Question 6

why does sigmoid growth curve reach a plateau

Answer 6

environment can no longer further increase in population

Question 7

what is population controlled by

Answer 7

negative feedback by density-dependent factors

Question 8

limiting factors that contribute the carrying capacity [6]

Answer 8

1. food and water availability
2. space for territories and nesting
3. availability of mates
4. disease
5. predation
6. environmental change

Question 9

invasive species eg

Answer 9

eurasian collared bird
from asia then got to europe and america

Question 10

importance of natality (reproductive rate)

Answer 10

ensures population continues

Question 11

3 numbers that affect population

Answer 11

1. natality
2. mortality
3. carrying capacity

Question 12

method to estimate population

Answer 12

capture-mark-release-recapture

Question 13

lincoln index

Answer 13

(m x n) / r
m- og individuals caught and marked
n- recaptured
r- recaptured with marks

Question 14

competitive community interaction eg

Answer 14

competition for light in plants

Question 15

cooperation community interaction eg

Answer 15

defence against predation in animals
mackerel swimming in a bait ball

Question 16

estimation of sessile organisms

Answer 16

quadrats

Question 17

invasive species eg

Answer 17

house crow
- causes nuisance to residential areas