Ecological Relationships And Energy Flow

Question 1

What is biodiversity?

Answer 1

Biodiversity is the measure of the number of species in an area

Question 2

What is a habitat?

Answer 2

The place where an organism lives

Question 3

What is a population?

Answer 3

The number of one type of organism in an area

Question 4

What is a community?

Answer 4

The total number of organisms from all the populations in one area

Question 5

What is an environment?

Answer 5

The factors, both physical (abiotic) and living (biotic), that affect organisms in a habitat

Question 6

What is an ecosystem?

Answer 6

The community of organisms that are interdependent on each other and the environment in which they live

Question 7

What are abiot factors? Give some examples

Answer 7

Abiotic factors are non-living factors that affect the distribution of plants and animals. Some examples include :

1. Wind which can be measured using anemometers
2. Water. Soil moisture levels can be calculated by taking soil samples and weighing the to find their mass, drying them in an oven and then reweighing them. The difference in mass as a percentage of the original mass gives a value for the percentage of water in the soil.
3. pH which can be measured using paper
4. Light which can be measured using light meters
5. Temperature which can be measured using a thermometer

Question 8

How can the percentage cover of plants be measured?

Answer 8

Using quadrants

Question 9

What are plants in completion with each other for?

Answer 9

Water, light, space and minerals /nutrients

Question 10

What are animals in competition with each other for?

Answer 10

Water, food, territory and mates

Question 11

What are consumers?

Answer 11

Green plants that absorb light and make their own energy through photosynthesis

Question 12

How is energy lost in a food chain?

Answer 12

Respiration/heat

Question 13

How does decomposition happen?

Answer 13

Saprophytic bacteria and fungi secrete enzymes into the soil or dead organisms. The enzymes break down the organic material and it is then absorbed by the bacteria or fungi.

Question 14

What are the optimum conditions for decomposition?

Answer 14

A warm temperature, adequate moisture and a large surface area in the decomposing organism

Question 15

Which bacteria convert ammonium compounds into nitrates?

Answer 15

Nitrifying

Question 16

Which bacteria convert nitrogen gas into nitrates and where are they found

Answer 16

Nitrogen fixing bacteria and they are found in the soil and root nodules

Question 17

Which bacteria convert nitrates into atmospheric nitrogen and where are they mostly found?

Answer 17

Denitrifying bacteria and they are mostly found in waterlogged soils

Question 18

How can the processes of nitrification and denitrification be accelerated?

Answer 18

Higher temperatures and well aerated soil

Question 19

How are root hair cells adapted for the uptake of nitrates, other minerals and water?

Answer 19

A large surface area

Question 20

What happens in eutrophication

Answer 20

1. Fertiliser run off increases the level of nitrates in nearby rivers
2. Increased nitrates cause increased growth in plants, blocking off light form smaller plants below and making them die
3. The dead plants are decomposed by bacteria
4. The bacteria use lots of oxygen for respiration which causes the oxygen levels to decrease
5. Fish suffocate due to lack of oxygen