4.1.4 Abiotic & Biotic Factors

Question 1

In Biology, ‘abiotic’, means what?

Answer 1

means non-living

Question 2

An abiotic factor is, what?

Answer 2

a non-living factor within an environment such as temperature, light intensity and wind speed

Question 3

(Abiotic Factor) Light Intensity

Answer 3

Light is needed by plants for photosynthesis. More light leads to an increase in rate of photosynthesis and an increase in plant growth rate.

Question 4

(Abiotic Factor) Temperature

Answer 4

Affects the rate of photosynthesis in plants

Question 5

(Abiotic Factor) Moisture Levels

Answer 5

Plants and animals require water to survive

Question 6

(Abiotic Factor) Soil pH and mineral content

Answer 6

Different species of plants are adapted to different soil pH levels and nutrient concentration levels

Question 7

(Abiotic Factor) Wind intensity and direction

Answer 7

Wind speed affects the transpiration rate in plants, transpiration affects the rate of photosynthesis as it ensures water and mineral ions are transported to the leaves.

Question 8

(Abiotic Factor) Carbon Dioxide levels for plants

Answer 8

CO2, is required for photosynthesis in plants. CO2 concentration affects the rate of photosynthesis

Question 9

(Abiotic Factor) Oxygen levels for aquatic animals

Answer 9

Some aquatic animals (such as fish) can only survive in the water with oxygen concentrations

Question 10

Exam Tip

Answer 10

You should be able to extract and interpret information from charts, graphs and tables relating to the effect of abiotic factors on organisms within a community

Question 11

Example exam answer

Answer 11

As CO2 concentration increases, average plant height also increases. For example, at 5% CO2, the average plant height was 10cm, but at 30% CO2, the average plant height was 60cm. This shows that the higher the CO2 concentration, the greater the plant growth rate. This is because CO2 is used by plants for photosynthesis, which allows the plant to produce glucose for energy to grow

Question 12

In Biology, ‘biotic’, means what?

Answer 12

means living

Question 13

What is a biotic factor

Answer 13

A biotic factor is a living factor in the environment such as competition, predation and disease

Question 14

Example exam answer (biotic factor)

Answer 14

As the number of grey squirrels increases, the number of red squirrels decreases. This might have occurred because the two squirrel species are competing for one or more of the same resources. Grey squirrels are better adapted to use these resources and have outcompeted the red squirrels until eventually there are too few red squirrels left to breed successfully and there are none left in the habitat.

Question 15

Exam Tip

Answer 15

When answering questions that refer to a chart, graph or table, remember to reference specific figures from the data to support your answer, as seen in the example above.

Question 16

(Biotic Factor) Availability of food

Answer 16

More food means organisms have a higher chance of surviving and reproducing. This means their populations can increase

Question 17

(Biotic Factor) New predators

Answer 17

In balanced ecosystems, predators catch enough prey to survive but not so many that they wipe out the prey population. If a new predator is introduced to the ecosystem, it may become unbalanced

Question 18

(Biotic Factor) New pathogens

Answer 18

If a new pathogen enters an ecosystem, the populations living there will have no immunity or resistance to it and the population may decline or be wiped out.

Question 19

(Biotic Factor) Competition

Answer 19

If two species compete for the same resource(s) and one is better adapated to take advantage of these resources, then that species will outcompete the other. This may continue until there are too few members of the lesser adapted species to breed successfully