Ecosystem and energy transfer

Question 1

definition of community

Answer 1

multiple populations living and interacting in the same area

Question 2

ecosystem definition

Answer 2

a community and its interactions with the non-living parts of its habitat

Question 3

population definition

Answer 3

all of the individuals of one species living in a habitat

Question 4

what are biotic and abiotic factors

Answer 4

Abiotic factors are non-living factors that influence populations within their community

Biotic factors are living factors that influence populations within their community

Question 5

what is systematic sampling

Answer 5

positions of the sampling points are located at fixed intervals throughout the sampling site

Question 6

what is succession

Answer 6

idea of a series of changes (that occur to the composition of species in the community) of organisms ( present in an area over a period of time:

Question 7

what is primary succession

Answer 7

when newly formed or newly exposed land is inhabited by an increasing number of species

Question 8

explain secondary succession and colonisation

Answer 8

secondary succession occurs with existing soil clear of vegetation

The area is first colonised by pioneer species such as lichens. As organisms die they are decomposed adding humus leading to formation of soil making it suitable for complex organisms.

more decomposition makes soil richer in minerals allowing plants to survive - climax community established.

Question 9

how may an island appear five years before and after a picture

Answer 9

5 years before
more { algae / lichens / mosses } present;
because these are {simpler organisms / early colonisers / pioneer species / eq};
less H. pebloides present / eq;
because recently colonised area / eq;

5 years after
more H. pebloides present / eq;
because had a longer period of time to become established / eg;
idea that {grasses / ferns / small shrubs / eq} present ;
because these are {higher organisms / next group of colonisers} / eq
OR
idea of improvement in soil structure;

Question 10

describe how to carry out a study to compare distribution of honckenya pebloides on two different parts of an island

Answer 10

idea of measuring off two areas of the same size;
use of a {quadrat / eq} ;
use of random {coordinates / sampling / eq} ;
method of generating random coordinates;
description of estimate of abundance e.g. number of plants, percentage cover
indication that several sample sites used;
appropriate method of recording quantitative data;

Question 11

how to test water availability in two parts of island

Answer 11

use moisture probe to test soil around plants

Question 12

climax community

Answer 12

final community that is self sustaining

Question 13

what is reproductively isolated population

Answer 13

idea of no {(inter) breeding / reproduction / mating / eq} (between the B. Selene);
2. (because) {geographical / physical} barrier / eg;
3. idea of different behaviour ;