11. biodiversity and adaptions

Question 1

define biodiversity

Answer 1

biodiversity is the range and variety of individuals and species in an environment.

Question 2

define ecosystem

Answer 2

an ecosystem is made up of an number of habitats, place in which an organism lives.

Question 3

define community

Answer 3

all the organisms in the eco system is known as a community

Question 4

define community

Answer 4

all the organisms in the eco system is known as a community

Question 5

define niche

Answer 5

each organism has a role to play within the ecosystem and this is called its niche.

Question 6

Food chains

Answer 6

• plants are producers.
• animals/fungi are consumers.
• the transfer of energy and food from one organism to another can be shown in the food chain.

Question 7

food webs

Answer 7

• food chains are linked together in a more complex food web.
• the position of an animal in a food chain with respect to its eating habits and surroundings is it niche.
• decomposers are essential in ecosystems as they recycle nutrients and breakdown dead remains e.g fungi, bacteria.

Question 8

adaptions to habitats and niche

Answer 8

darwins finch show that the shape and size of a beak of a finch species has adapted to exploit different niches.
This allows more niches to be adapted, increases biodiversity.

Question 9

biodiversity is affected by three factors

Answer 9

1. abiotic factors (non living) e.g temperature, pH etc.
2. biotic factors (living) e.g predators, disease
3. human influence

Question 10

link to genetics

Answer 10

all features of an organism are controlled by genes.
Genotype ; genes that an organism posses
phenotype; appearance of an organism

Question 11

environmental impact on phenotype

Answer 11

all organisms final appearance (phenotype) is a result of the interaction of the environment and genotype.

Question 12

natural selection

Answer 12

organisms that are suited to their environment survive, breed and pass on their genes.

over a long time natural selection can lead to the gradual evolution of a new species.

Question 13

the peppered moth example.

Answer 13

two generic forms of this moth
1. a light form (peppered)
2. a dark form (melanic)
The melanic form had an advantage as it was camouflaged against the soot. However the peppered form was easily seen and predated.
In areas, not affected by pollution it was the opposite, the peppered moth was camouflaged and the dark form was seen and predated.

Question 14

speciation

Answer 14

formation of a new species. Evolution is the mechanism that brings about speciation. These changes are adaptive and make the organism more suited to its environment.

Question 15

isolating mechanisms

Answer 15

geographical barriers; oceans, mountains, rivers

ecological barriers; pH, temperature, humidity

Reproductive barriers; different breeding seasons

Question 16

what happens once both populations have become separated

Answer 16

• when populations become isolated there is no interchange of genes between groups. Mutations and natural selection will defer in each group.
• Each group will therefore evolve differently and gene pools will gradually become different.
• If over a long period of time they are sufficiently different from each other they will no longer be able to breed and produce fertile offspring.
• They are now a different species.

Question 17

indicator species

Answer 17

these are organisms that can be used to indicate how polluted or clean an environment is. These species can be used to monitor and record.
Examples of species to indicate clean freshwater environments are the may fly B, both require oxygen rich water. Other species such as ratiloiled maggot and sludge worms only lives in highly polluted water.
Lichen are a good indicator of air pollution , they are sensitive to sulphur and do not grow in areas of high pollution.