B12 - Organisms and their Environment

Question 1

Principle source of energy

Answer 1

The Sun

Question 2

Producers

Answer 2

Organisms that produce their own organic nutrients usually using energy from sunlight
* plants are producers as they carry out photosynthesis to make glucose

Question 3

Herbivore

Answer 3

An animal that gets its energy by eating plants (they are primary consumers)

Question 4

Carnivore

Answer 4

An animal that gets its energy by eating other animals (they are secondary consumers)

Question 5

Primary consumers

Answer 5

Feed on producers (herbivores)

Question 6

Secondary consumers

Answer 6

Feed on primary consumers (carnivores/predators)

Question 7

Tertiary consumers

Answer 7

Predators that feed on secondary consumers

Question 8

Decomposers

Answer 8

Bacteria and fungi that get their energy from feeding off dead and decaying organisms and undigested waste by secreting enzymes to break them down

Question 9

Autotrophic organisms (give 1 example)

Answer 9

Organisms which create their own food / produce their own energy (through the use of inorganic material)
* e.g. algae (and many other plants)

Question 10

Heterotrophic organisms (give 1 example)

Answer 10

Organisms which gain energy and nutrients from other animals or plants (use organic material)
* e.g. sheep (can be both a carnivore or a herbivore)

Question 11

Saprotrophic organisms (give 1 example)

Answer 11

Organisms that obtain their nutrients from dead or decaying organic matter
* e.g. mushroom

Question 12

Food chain

Answer 12

Shows the transfer of energy from one organism to the next, starting with a producer

Question 13

What do the arrows in a food chain show?

Answer 13

The transfer of energy by ingestion

Question 14

Food web

Answer 14

A network of interconnected food chains
* more realistic as animals rarely exist on just one type of food source

Question 15

Interdependence

Answer 15

How the change in one population can affect others within the food web

Question 16

Pyramid of numbers

Answer 16

Shows how many organisms we are talking about at each level of a food chain
* width of the box indicated the number of organisms at that trophic level

Question 17

Why are there fewer than 5 trophic levels in a food chain?

Answer 17

Due to the loss of energy between each level of consumers

Question 18

How is energy lost between the trophic levels?

Answer 18

MRS GREN

Question 19

Ecosystem

Answer 19

A unit containing all of the organisms and their environment, interacting together, in a given area, e.g. a lake

Question 20

Trophic level

Answer 20

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

Question 21

How is energy passed between the trophic levels?

Answer 21

An organism eats another organism and gets the energy-rich molecules from it’s orey’s body

Question 22

Population

Answer 22

A group of organisms of one species, living in the same area at the same time

Question 23

Community

Answer 23

All of the populations of different species in an ecosystem

Question 24

Factors controlling population growth (3)

Answer 24

• Food supply
• Predation
• Disease