Ecosystems 3.1

Question 1

The total variety of all living things
on Earth is described as

A. an ecosystem
B. biodiversity
C. a population
D. competition

Answer 1

B. BIODIVERSITY

Question 2

A rabbit feeds on grass, is eaten by foxes and is a habitat for fleas.

The statement above describes the rabbit’s
A. ecosystem
B. community
C. niche
D. prey

Answer 2

C. Niche

Question 3

The diagram below represents a freshwater food web.

The number of freshwater shrimps was found to have decreased dramatically.
Predict the effect this will have on the numbers of dragonfly nymphs and microscopic algae.

A. Both populations would decrease.
B. Both populations would increase.
C. Microscopic algae would decrease and dragonfly nymphs would increase.
D. Microscopic algae would increase and dragonfly nymphs would decrease.

Answer 3

D. Microscopic algae would increase and dragonfly nymphs would decrease.

Question 4

The diagram below shows part of a food web in an oak woodland.

The use of insecticides in a nearby field resulted in the death of most aphids and caterpillars.

Which line in the table identifies the effect on the numbers of slugs and carnivorous insects?

-Number of slugs
A. Decreases
B. Increases
C. Decreases
D. Increases
-Number of carnivorous insects
A. Stays the same
B. Decreases
C. Increases
D. Stays the same

Answer 4

B. Increases | decreases

Question 5

Which of the following statements about a woodland describes a community?

A. All the oak trees
B. All the plants
C. All the oak trees and blackbirds
D. All the plants and animals

Answer 5

D. All the plants and animals

Question 6

An ecosystem receives 6 000 000 units of energy from the sun. Of this energy, 95% is not used in photosynthesis.

The amount of energy captured by the producers in this ecosystem is:

A. 30 000
B. 300 000
C. 570 000
D. 5 700 000.

Answer 6

B. 300 000

Question 7

The size of a population of snails can be estimated using the following formula.

Humber collected on Ist day x Humber collected on 2nd day
Population=————————————
Humber of marked individuals found on 2nd day

A student investigated the population of snails in a garden. He collected 40 snails, marked their shells and released them. Next day, 35 snails were collected and 14 of these were found to be marked.

The snail population was estimated to be

A. 16
B. 100
C. 560
D. 1400.

Answer 7

B. 100

Question 8

The diagram below shows part of a food chain in the Arctie tundra.

A population in this food web is all the

A. plants
B. reindeer
C. animals
D. living organisms

Answer 8

D. living organisms

Question 9

A species can be defined as a group. of organisms which:

A. Breed together to produce fertile offspring
B. Have the same features
C. Contain the same number of chromosomes
D. Contain Identical genetic material

Answer 9

A. Breed together to produce fertile offspring

Question 10

Which of the following is a habitat?

A. A rock pool
B. All animals and plants in a rock pool
C. The sandy bottom of a rock pool
D. The barnacles in a rock pool

Answer 10

B. All animals and plants in a rock pool

Question 11

Which row in the table describes a type of competition and a matching example?

Type of competition
A. Interspecific
B. Interspecific
C. Intraspecific
D. Intraspecific

Example
A. Two birch trees growing close together in a wood
B. Lions and hyenas feeding on zebra
C. Seals and dolphins feeding on small fish
D. Buttercups and daisies growing in the same field

Answer 11

B. Interspecific | Lions and hyenas feeding on zebras

Question 12

Which of the following statements best describes a niche?

A. A living factor which affects biodiversity in an ecosystem.
B. A region of our planet as distinguished by its climate, fauna and flora.
C. All the organisms in an area and their habitat.
D. The role that an organism plays with in a community.

Answer 12

D. The role that an organism plays with in a community.

Question 13

The statements below relate to bird behaviour.

Blackbirds sing to mark their territory.
Arctic and common terns form large mixed breeding colonies.
Black grouse gather on open areas of short grass and males display to females.
Great skuas chase other seabirds and force them to drop their food.

Which of the above statements are related to intraspecific competition?

A. 1 and 2 only
B. 1 and 3 only
С. 2 and 4 only
D. 3 and 4 only

Answer 13

B. 1 and 3 only

Question 14

Which of the following examples of bird. behaviour would result in reduced interspecific competition?

A. Great Tits with the widest stripe on their breast feed first when food is scarce.
B. Sooty Terns feed on larger fish than other species of tern which live in the same area.
C. Pelicans searching for food form a large circle round a shoal of fish, then dip their beaks into the water simultaneously.
D. Predatory gulls have difficulty picking out an individual puffin from a large flock.

Answer 14

B. Sooty Terns feed on larger fish than other species of tern which live in the same area.

Question 15

In which of the following would competition not occur?

A. Rabbits grazing in a field
B. Owls and foxes hunting for mice
C. Daisies and dandelions growing in a lawn
D. Algae and fish in a loch

Answer 15

A. Rabbits grazing in a field

Question 16

Which of the following describes interspecific competition?

A. Individuals of different species requiring different resources.
B. Individuals of different species requiring similar resources.
C. Individuals of the same species requiring different resources.
D. Individuals of the same species requiring similar resources.

Answer 16

B. Individuals of different species requiring similar resources.

Question 17

The Scottish crossbill is a small bird which is native to Scotland. It inhabit pine forests in northern Scotland and feeds on pine seeds using its crosse
beak.

(a) State the term used to describe the role of the Scottish crossbill within its community.

(b) The Scottish crossbill has been classified as a separate species, but can still mate with other spegies, of crossbill.

Give a feature of any offspring produced from this mating, which proves that the parents are different species.

Answer 17

(a) Niche
(b) Infertile

Question 18

A food chain from a river is shown below.

algae —> water flea —> stickleback—> perch

Using the information in the food chain, answer the following questions.

(a) (i) Identify an organism which is both predator and prey.

Answer 18

(a) (i) Stickle back

Question 19

In an investigation, students estimated the population and biomass of some organisms found on part of a rocky shore.
The table below shows the results.

Organism | population
-Seaweed | 220
-Limpet |1 100
-Crab |100
-Gull |5

Average mass of one organism (g)
500
90
700
Biomass of population (g)
110 000
33 000
9 000
3 500

During the investigation the students found four different species of periwinkles at different positions on the rocky shore.

The highest position that the sea water reaches on the shore is called the high tide level.

The bars in the table below represent the positions on the shore where each species of periwinkle was found.

       Species of periwinkle Position on |Small|Edible|Rough|Flat  shore.           | 

-High tide level
|
|
-Low tide level

(i) State which species of periwinkle is least likely to compete with the small periwinkle.

Explain your answer.

Species__________
Explanation ___________

(ii) Using the information given, explain why the competition between
these periwinkles is described as interspecific.

Answer 19

(i)Species— flat
Explanation—low tide level which is further away from the high tide level

(ii) It is competition between different species for some of He same food.