Unit 3 - Life On Earth

Question 1

what does biotic mean ?

Answer 1

biotic - are factors in the ecosystem related to living things e.g competition for food, space, preparation and disease

Question 2

what’s does abiotic mean?

Answer 2

abiotic - are non-living factors in the ecosystem e.g. pH, light moisture, temperature, flow rate etc

Question 3

what does habitat mean?

Answer 3

habitat - this is the place where an organism lives

Question 4

what does population mean?

Answer 4

population - a group of organisms of the same species

Question 5

what does community mean?

Answer 5

community - this is the sum total of all the populations of plant and animals living together

Question 6

what does ecosystem mean?

Answer 6

ecosystem - this is the balanced interaction between the member is a community and their habitat

Question 7

what is a food chain ?

Answer 7

food chains are often used to show the feeding relationships between different organisms

Question 8

what do arrows in a food chain show

Answer 8

they show the direction of energy flow

Question 9

what is a herbivore

Answer 9

herbivore - is an organism which eats plants only

Question 10

what is a carnivore?

Answer 10

carnivore - eats other animals

Question 11

what is a omnivore?

Answer 11

omnivore- eats both plants and animals

Question 12

what can a pyramid of numbers be used to show?

Answer 12

a pyramid of numbers can be used to show the number of organisms at each stage of a food chain (doesn’t have to be a pyramid)

Question 13

what is the chemical symbol for nitrogen? and what’s the important of this nutrient to plants?

Answer 13

the chemical symbol for nitrogen is N and it’s important to plants because it promotes leaf growth

Question 14

what is the chemical symbol for phosphorus? and what’s the important of this nutrient to plants?

Answer 14

the chemical symbol for phosphorus is P and it’s important to plants because it promotes leaf growth

Question 15

what is the chemical symbol for potassium? and what’s the important of this nutrient to plants?

Answer 15

the chemical symbol for potassium is K and it’s important to okays because it promotes growth of flowers and fruits

Question 16

what is a fertiliser?

Answer 16

a fertiliser is a substance containing extra supplies of the nutrients needed by growing plants

Question 17

what is photosynthesise?

Answer 17

photosynthesis is a chemical reaction in plants which makes food using light, carbon dioxide, and water they produce oxygen

Question 18

what is chlorophyll?

Answer 18

it’s a green pigment found in chloroplasts

Question 19

what does chlorophyll do?

Answer 19

it absorbs sunlight which will then be used to drive the photosynthesis reaction

Question 20

what are some uses of glucose made during photosynthesis?

Answer 20

used in respiration to release energy

continued to starch (storage carbohydrate)

converted to cellulose (used to make cell walls)

Question 21

how is ATP made?

Answer 21

when glucose is broken down it’s energy is used to make ATP

Question 22

what happens to a enzyme when it gets too hot?

Answer 22

it denatures

Question 23

what is a mutation?

Answer 23

a mutation is a sudden random change in the number or structure of an organisms chromosomes (DNA)

Question 24

what is a gene?

Answer 24

a gene is a section of DNA which codes for a particular protein and therefore one characteristic, e.g. the gene for eye colour

Question 25

what is interspecific competition ?

Answer 25

competition between different species

Question 26

what is intraspecific competition?

Answer 26

competition between same species

Question 27

what are problems with pitfall traps?

Answer 27

water getting in when it rains

birds taking trapped animals

predatory animals like spiders, ground beetles or centipedes eating their fellow captives

Question 28

what are quadrats used for?

Answer 28

quadrats are used for estimating the abundance of plants or animals that don’t move

Question 29

what are herbicides used to kill?

Answer 29

herbicides are used to kill weeds which compete with the crop and remove valuable nutrients from the soil

Question 30

what part of the brain speeds up the heart rate during exercise?

Answer 30

medulla

Question 31

what part of the brain is responsible for memory?

Answer 31

cerebrum

Question 32

how many chromosomes does a human have?

Answer 32

46 chromosomes

Question 33

what kind of cells are found in the brain?

Answer 33

neurone’s

Question 34

which organ has 4 chamber’s?

Answer 34

the heart

Question 35

which part of the brain is responsible for balance and coordination ?

Answer 35

cerebellum