B18- Organisms and their environment

Question 1

What is the principal source of energy input into the biological systems

Answer 1

Sun

Question 2

What is the process that converts light energy into chemical energy

Answer 2

Photosynthesis
- Producer (plant) uses photosynthesis to convert

Question 3

What do arrows symbolise in a food chain or web

Answer 3

Energy flow/transfer

Question 4

Define Food web

Answer 4

a network of interconnected food chains

Question 5

Define Food chain

Answer 5

Diagram that shows the transfer of energy from one organism to the next

Question 6

Describe Producer [3]

Answer 6

An organism that makes its own organic nutrients, usually using energy from sunlight, through photosynthesis
T1
producer

Question 7

Describe Consumer [3]

Answer 7

An organism that gets its energy by feeling on other organisms
T2, T3, T4 - possibly more
primary, secondary tertiary

Question 8

Define Herbivore

Answer 8

An animal that gets its energy by eating plants

Question 9

Define Carnivore

Answer 9

An animal that gets its energy by eating other animals

Question 10

Define Decomposer

Answer 10

An organism that gets its energy from dead or waste organic material

Question 11

Answer structure when talking about affects on food chain

Answer 11

1- Trophic levels above
2- Trophic levels below

Question 12

Define Trophic level

Answer 12

The position of an organism in a food chain and food web

Question 13

What happens to energy when it gets passed on from one organism to another

Answer 13

About 90% is lost

Question 14

Why isn’t 100% of energy passed on through Trophic levels [4]

Answer 14

1. consumers don’t eat everything + don’t digest everything
2. Used up in movement
3. Used up in maintaining body temperature
4. Used up in excretion

Question 15

Why is there usually no more than 5 trophic levels?

Answer 15

Not enough energy to support higher trophic levels

Question 16

Efficiency of energy transfer formula

Answer 16

Efficiency= energy transferred to next level/ energy received from previous level x 100

Question 17

Define Decomposition/decay

Answer 17

The breakdown of organic matter (dead organisms or waste material)

Question 18

Overharvesting (overgrazing or overfishing) impact [3]

Answer 18

1. decrease in biodiversity
2. natural food chain of habitat disrupted
3. risk of extinction of a species

Question 19

Impact of introducing a foreign species [7]

Answer 19

1. disrupts natural food chain
2. competes with existing species for resources
3. could cause native species to migrate
4. no natural predators to control
5. could introduce disease
6. could reduce biodiversity
7. could cause extinction of other species

Question 20

Why is it more efficient for humans to be vegetarian? [3]

Answer 20

1. energy is lost at each trophic level
2. plants are lower down the food chain and so less energy has been lost
3. so its a lot more efficient for humans to eat plants than animals

Question 21

In what ways does Carbon leave the atmosphere?

Answer 21

Photosynthesis

Question 22

In what ways does Carbon enter the atmosphere? [2]

Answer 22

Respiration
Combustion

Question 23

Define Fossilization

Answer 23

Process where the remains of the dead plants and animals are preserved in rock or other material over millions of years