B18 - Organisms and their environment

Question 1

explain energy flow in biological systems

Answer 1

The sun is the principal source of energy input
light energy from the sun and chemical energy in organisms transfers to the environment

Question 2

producer definition

Answer 2

an organism that makes its own organic nutrients, generally using energy from sunlight, through photosynthesis

Question 3

ecosystem definition

Answer 3

a unit containing all of the organisms in a community and their environment, interacting together

Question 4

herbivore definition

Answer 4

an animal that gets its energy by eating plants

Question 5

carnivore definition

Answer 5

an animal that gets its energy by eating other animals

Question 6

omnivore definition

Answer 6

an animal that gets its energy by eating plants and other animals

Question 7

community definition

Answer 7

all of the populations of all the different species in an ecosystem

Question 8

population definition

Answer 8

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

Question 9

habitat definition

Answer 9

the place where an organism lives

Question 10

consumer definition

Answer 10

an organism that gets its energy from feeding on other organisms

Question 11

biodiversity definition

Answer 11

the number of different species that live in an area

Question 12

decomposers definition

Answer 12

organisms that break down organic substances outside their bodies, releasing nutrients from them that other organisms can use
get its energy from dead or waste organic material

Question 13

trophic level definition

Answer 13

otherwise known as feeding level
the position of an organism in a food chain and food web (producer, primary consumer/herbivore, secondary consumer/carnivore, tertiary consumer/predator, quaternary consumer)

Question 14

predator definition

Answer 14

kill prey for food
tertiary consumer

Question 15

prey definition

Answer 15

the animals that are killed by the predators/tertiary consumers

Question 16

primary consumer definition

Answer 16

animals that eat or consume the producers
herbivores

Question 17

secondary consumer definition

Answer 17

animals that consume the primary consumers
carnivores

Question 18

tertiary consumer definition

Answer 18

animals that eat the secondary consumers/carnivores
these are hunters that hunt, catch, and kill their prey for food
they are not normally killed by other animals
top of the food chain

Question 19

layers in a woodland

Answer 19

canopy layer - trees
shrub layer
herb layer
ground layer

Question 20

explain why food chains usually have fewer than five trophic levels

Answer 20

energy is lost from one trophic level to another which means each trophic level has to eat more of the last trophic level to have enough energy, which limits food chains to fewer than five trophic levels

Question 21

explain why the transfer of energy from one trophic level to another is often not efficient

Answer 21

as one trophic level animal eats another organism, it does not get all the energy that organism started with, as some of the energy was used and the animal could not take all the energy when it ate the animal

Question 22

explain why it is more energy efficient for humans to eat crop plants than to eat livestock that have been fed on crop plants

Answer 22

since humans eating plants is only one process compared to humans eating livestock that ate plants, which is two processes, so there is less energy lost due to one organism consuming another organism, which makes it more energy efficient

Question 23

describe the carbon cycle (6)

Answer 23

photosynthesis
respiration
feeding
decomposition
formation of fossil fuels
combustion

Question 24

decay meaning

Answer 24

caused by bacteria and fungi breaking down dead material and animal waste. As they do this, they respire and so release carbon dioxide

Question 25

photosynthesis word equation

Answer 25

carbon dioxide + water –> glucose + oxygen

Question 26

respiration word equation

Answer 26

glucose + oxygen –> water + carbon dioxide

Question 27

combustion word equation

Answer 27

hydrocarbon fuel + oxygen –> carbon dioxide + water

Question 28

death definition

Answer 28

the ending of life

Question 29

burning/combustion definition

Answer 29

release of energy from fossil fuels

Question 30

respiration definition

Answer 30

the release of energy in living cells which produces carbon dioxide
the chemical reactions in cells that break down nutrient molecules and release energy for metabolism

Question 31

feeding/consumption definition

Answer 31

consumers taking in food

Question 32

photosynthesis definition

Answer 32

the process by which a green plant makes its own food

Question 33

burial and sedimentation definition

Answer 33

formation of fossils