Unit 3

Question 1

Give the definition of a biome

Answer 1

Region of the planet with characteristic climate, fauna and flora

Question 2

Give three examples of global biomes

Answer 2

Tropical rainforest, dry grassland, tundra shallow seas

Question 3

Give two factors that affect the global distribution of biomes

Answer 3

Temperature, rainfall

Question 4

State what is meant by the following terms. Ecosystem, biodiversity

Answer 4

Ecosystem, habitat with its community and nonliving components. Biodiversity, variety and number of species

Question 5

Give two examples of abiotic factors in an ecosystem

Answer 5

PH, temperature

Question 6

Give two examples of biotic factors in an ecosystem

Answer 6

Grazing, predation

Question 7

State what is meant by an organisms niche

Answer 7

The role organism plays within its community

Question 8

Give one example of human influences that might affect biodiversity and ecosystem and describe its affect

Answer 8

SO2, pollution from burning fossil fuels, which damages plants; overgrazing, which damages plant communities and causes erosion of soil

Question 9

Describe what is meant by the following terms: competition, predation.

Answer 9

Competition, struggle between or within species for resources that are in short supply. Preparation, animals hunting and feeding on the flesh of other animals

Question 10

Explain how each of the following factors can affect organisms in an ecosystem in. Light, temperature, nutrient availability

Answer 10

Light affects the growth of green plants, temperature affects enzymes systems, nutrient availability affects plant growth

Question 11

Give an account of the factors that define and organisms niche

Answer 11

What it feeds on, what feet on it, what other resources it uses, what organisms it interact with, what it adds to the environment

Question 12

What does the food chain diagram look like for grass plants that are grazed by rabbits which are prayed upon by foxes

Answer 12

Grass forward arrow rabbit forward arrow fox

Question 13

From the following food chain diagram name the producer, the primary consumer, the carnival. Oakleaf forward arrow caterpillar forward arrow blue tit forward arrow sparrowhawk

Answer 13

Producer, Oakleaf. Primary consumer, caterpillar. Carnivore, blue tit or sparrowhawk

Question 14

Account for the loss of energy at each level in a food chain

Answer 14

Energy can be lost by movement and is heat

Question 15

State why nitrates are needed by living organisms

Answer 15

They are needed to make proteins and nucleic acid’s

Question 16

Give the difference between interspecific and intra specific competition

Answer 16

Interspecific is competition between members of different species, intraspecific is between members of the same species

Question 17

Give the meanings of the following terms: habitat, population, community, ecosystem.

Answer 17

Habitat, place in which an organism lives. Population, number of given species within the habitat. Community, all of the living organisms in a habitat. Ecosystem, habitat its community and nonliving components

Question 18

Explain why decomposition can account for some of the losses that occur to energy transfer in a food chain

Answer 18

Dead organisms from the chain entering the decomposition cycle; rather than being consumed by the next level of the food chain they enter the decompose of the chain

Question 19

Pyramid diagrams are used to represent food chains, explain what is represented by the following pyramids; numbers, biomass, energy

Answer 19

Populations of each organism at each level of the food chain.

Question 20

State the meaning of the following processes of the nitrogen cycle: nitrogen fixation, nitrification, dentrification, decomposition

Answer 20

Turning atmospheric nitrogen into nitrate by bacteria.
loss of nitrogen by conversation of nitrates into nitrogen gas.
production of nitrates from other compounds by soil bacteria.
breakdown of bodies of organisms following death.

Question 21

Give an account of the roles of bacteria in the nitrogen cycle.

Answer 21

Bacteria released nitrates from organic material in soil; convert atmospheric nitrogen to nitrate; convert soil nitrate to nitrogen gas; fix nitrogen directly inside certain plants.

Question 22

Give an example of two abiotic factors.

Answer 22

Temperature, rainfall….

Question 23

Describe the following biotic factors predation and competition

Answer 23

Predation is a relationship in which one animal hurts and it’s another.

Competition occurs when organisms struggle against others for similar resources.

Question 24

State what is meant by a sample.

Answer 24

Is small, representative portion of a larger quantity.

Question 25

Name the techniques that could be used to sample the following organisms: Dandelion roots in a field of ryegrass.

Beatles the move around the soil surface at night In grassy areas.

Answer 25

Quadrat, pitfall trap

Question 26

Give two sources of error that can affect sampling using quadrat.

Answer 26

Failure to use enough quadrat; using an appropriate size quadrat; failure to randomise the quadrat

Question 27

Give two sources of error that can be affected sampling using pitfall traps.

Answer 27

Failure to use enough traps; an appropriately sized trap; failure to randomise distribution and trap; tell you to check traps regularly.

Question 28

Give the term for a group of species.

Answer 28

A group of organisms interbreeding to produce fertile young.

Question 29

State what is meant by genetic mutation

Answer 29

Random change in genetic material

Question 30

Name two factors that can increase the rate of mutation

Answer 30

Radiation, chemicals

Question 31

State what is meant by neutral mutation

Answer 31

Confers new advantage of disadvantage to the organism

Question 32

State what is meant by the term natural selection

Answer 32

Survival of the fittest

Question 33

Give the meaning of the term adaptation

Answer 33

Special feature of an Organism that gives it the ability to survive

Question 34

Give an example of an adaptation in a named animal

Answer 34

Camouflage and fish; she lesion in Wales; length of giraffe; called colour and polar bears…

Question 35

State how each of the following improves crop yield in intensive farming methods: fertilisers, pesticides

Answer 35

Enhance cropland growth, kills species that damage crop growth

Question 36

Give one benefit Of intensive farming

Answer 36

Increases yield of crops

Question 37

State what is meant by the term algal bloom.

Answer 37

Abnormally high growth of algae

Question 38

Give the meaning of the term indicator species

Answer 38

Species whose presence, absence or abundance suggesting information about the state of the environment

Question 39

Give one example of an indicator species

Answer 39

Mayfly, Lichen…

Question 40

Name the gas the decreases in the water when a Rubik bacteria decompose dead algae

Answer 40

Oxygen