B8 - Feeding Relationships and Organisms

Question 1

calculate the percentage of wood lice found on black squares

Answer 1

13

so 65%

Question 2

all wood lice show this behaviour

state the term used to describe this type of behaviour

Answer 2

instinctive

Question 3

squirrels urinate on tree

explain how this behaviour benefits them

Answer 3

• squirrels mark territory
• use chemical markers
• to reduce conflict = reducing competition

Question 4

this type of behaviour is called

Answer 4

B - habituation

Question 5

calculate the percentage energy that is transferred from the rabbits to the fox

Answer 5

11.5%

90/780 x 100 = 11.5

Question 6

state two ways in which energy can be lost between the tropic levels of the rabbit and fox

Answer 6

• respiration

- excretion

Question 7

suggest how a farmer rearing chickens could limit energy loss from the chickens

Answer 7

• restrict movement

- keep them in a warm place

Question 8

explain the importance of this mutualistic relationship to legumes

Answer 8

• bacteria provides nitrates for the plant
• by converting nitrogen into nitrates
• which provide protein for growth

Question 9

nitrosomonas bacteria are an example of

Answer 9

B - nitrifying bacteria

Question 10

explain why nitrosomonas and nitrobacter are needed in tropical fish tanks

Answer 10

• they convert ammonia into nitrites which maintains pH

- this prevents increase in pH which would cause enzymes to denature and kill the fish

Question 11

explain how this aquatic plant can uptake nitrates from the water in the fish tank

Answer 11

• aquatic plant takes up nitrates by active transport

- against concentration gradient low to high

Question 12

describe how a quadrat could be used to sample the population of clover in a 500m field

Answer 12

• use quadrat against belt transact
• throw randomly and count number of clovers in quadrat
• multiply by number of quadrats sampled

Question 13

explain how leguminous plants such as clover could be used to reduce the amount of artificial fertilisers

Answer 13

• clover and legume plants could be used in crop rotation

Question 14

the oak tree obtains energy

Answer 14

A - autrophically

Question 15

suggest how energy is lost between tropic levels in this food chain

Answer 15

• excretion

- respiration