Unit 3- Life On Earth

Question 1

What is an organism’s ecological niche?

Answer 1

An organism’s ecological niche is its role it plays in an ecosystem.

Question 2

What are the stages of speciation?

Answer 2

Isolation
Mutation
Natural selection
Different gene pools
Speciation

Question 3

What is an isolation barrier?

Answer 3

An isolation barrier divides a population into two or more sub-populations. It acts as a barrier to gene flow.

Question 4

What organisms turn proteins into ammonium by using decomposition?

Answer 4

Decomposers- soil bacteria and fungi.

Question 5

What is the difference between interspecific and intraspecific competition?

Answer 5

Interspecific competition is between different species.

Intraspecific competition is between the same species.

Question 6

What is meant by the term invertebrate?

Answer 6

An organism without a backbone.

Question 7

What is the difference between abiotic and biotic factors?

Answer 7

Abiotic- Non-living factor.

Biotic- Living factor.

Question 8

What is a mutation?

Answer 8

A random change in the sequence of DNA.

Question 9

How much energy is passed on at each stage in a food chain?

Answer 9

10%

Question 10

Define biodiversity.

Answer 10

The variety of living things in an ecosystem.

Question 11

What is a species?

Answer 11

A species is a group of animals that can breed to produce fertile offspring.

Question 12

What is the purpose of a producer in a food chain?

Answer 12

Producers can make their own food and are vital to provide energy for the consumers.

Question 13

What is evolution?

Answer 13

Evolution is the scientific explanation for the biodiversity that has arisen over 3.5 billion years.

Question 14

Name 3 isolation barriers.

Answer 14

Geographical barrier
Reproduction barrier
Ecological barrier

Question 15

What do the arrows in a food chain show?

Answer 15

The arrows in a food chain shows the direction of energy flow.

Question 16

Name 3 abiotic factors.

Answer 16

Soil moisture, temperature and pH.

Question 17

Name three ways that 90% of energy is lost between each stage in a food chain.

Answer 17

Heat
Movement and
Undigested material

Question 18

Are mutations always negative?

Answer 18

Mutations can be positive, negative or neutral.

Question 19

What can be used to count numbers of plants?

Answer 19

Quadrat.

Question 20

What are pitfall traps used for?

Answer 20

Pitfall traps are used sample the small invertebrates living on the ground.

Question 21

Name the two types of mutation that can arise.

Answer 21

Gene mutation

Chromosome mutation.

Question 22

Name 4 biotic factors.

Answer 22

Predation
Competition
Disease
Grazing

Question 23

Name three TYPES of consumer and what food type they eat.

Answer 23

Herbivore- plants
Carnivore- Animals
Omnivores- plants and animals

Question 24

Define Biomes.

Answer 24

Biomes are areas of the planet that shares similar flora and fauna.

Question 25

State three adaptations of a predator.

Answer 25

Eyes to the front of the head.
Fast runner
Sharp teeth/ claws

Question 26

State the term used to describe an increased rate of mutation and name examples of ways to increase the rate of mutation.

Answer 26

Mutagenic agent.

Mustard gas or radiation.

Question 27

State examples of sampling technique.

Answer 27

Netting, pitfall traps, tree beating, quadrat.

Question 28

What is a producer?

Answer 28

A producer is a green plant which produces it’s own food.

Question 29

What rules should always be considered when using a quadrat?

Answer 29

Ensure its thrown randomly.

Ensure its thrown multiple times.

Question 30

What precautions should be considered whilst using pitfall traps.

Answer 30

Set trap at ground level.
Have a lid to protect from rain/predators
Holes at the bottom for drainage
Empty the trap regularly

Question 31

What is grazing?

Answer 31

Grazing is a biotic factor, if an area is undergrazed the biodiversity decreases. Overgrazing also reduces biodiversity.

Question 32

What is predation?

Answer 32

Predation is when one organism hunts another and can affect many species in an ecosystem.

Question 33

What is the difference between predator and prey?

Answer 33

Predator- animal that hunts others

Prey- animal being hunted.

Question 34

Define adaptation.

Answer 34

An inherited characteristic that makes an organism better suited to a changing environment.