B3

Question 1

Define the term “species”

Answer 1

A group of organisms that can breed together to produce fertile offspring

Question 2

Why is it important for an organisms to be adapted to its environment?

Answer 2

It increases the chance of survival by making it more likely that individual will survive to reproduce

Question 3

Living organisms are dependent on other species for survival for their survival, what is this called?

Answer 3

Interdependence

Question 4

There is competition for resources between different species of animals or plants in the same…

Answer 4

Habitat

Question 5

Give three example of changes in the environment that may cause a species to become extinct?

Answer 5

1. Environment changes beyond its ability to adapt
2. A new species that is a competitor, predator or disease organism is introduces
3. Another species in its food web becomes extinct

Question 6

All organism are ultimately dependent on energy from what?

Answer 6

The sun

Question 7

Absorbed energy from the Sun is stored as what type of energy?

Answer 7

Chemical

Question 8

Give two example of energy transfer between organisms in an ecosystem?

Answer 8

1. When organisms are eaten

2. When dead organisms and waste material are fed on by decay

Question 9

Explain what decomposers and detritivores?

Answer 9

Decomposers such as bacteria and fungi cause decay on a microscopic level.
Detritivores are organisms that help speed up decay by feeding on detritus. This dead and decaying material. They break it down into smaller pieces, so increasing the surface area for the bacteria and fungi.

Question 10

Name 3 types of detritivore organisms?

Answer 10

Earthworms that break down dead leaves
Maggots that feed on animal tissue
Woodlice that break down wood

Question 11

Food chains are limited n length because energy passes out of the food chain at each stage; why does this happen?

Answer 11

Energy is lost through heat, waste products and uneaten parts

Question 12

How is carbon dioxide removed from the atmosphere?

Answer 12

Green plants remove carbon dioxide from the atmosphere by photosynthesis. This carbon becomes part of the complex molecules such as proteins, fats and carbohydrates in the plants

Question 13

How is carbon dioxide returned into the atmosphere?

Answer 13

Organisms return carbon dioxide to the atmosphere by respiration

Question 14

How is carbon passed from one organism to the next?

Answer 14

When animal eat a plant , carbon dioxide from the microorganism and some animals feed on waste material from animals, and the remains of dead animals and plants . The carbon then becomes part of these microorganisms and detritus feeders.

Question 15

Why are microorganisms important in the carbon cycle?

Answer 15

Microorganisms and some animals feed on waste material from animals and the remains of dead animals and plants. The carbon then become part of these microorganisms and detritus feeders

Question 16

What is nitrogen fixation?

Answer 16

Making nitrogen compounds from nitrogen in the air

Question 17

What happens in nitrogen fixation?

Answer 17

• The energy in lightning splits nitrogen molecules into individual nitrogen atoms.These react with oxygen to form nitrogen oxides. Nitrogen oxides are washed to the ground by rain where they form nitrates in the soil
• Nitrogen-fixing bacteria found in the soil and in the root nodules of leguminous plants , such as peas , fix nitrogen gas into nitrogen compounds
• The Haber process is used by industry to produce ammonia from nitrogen and hydrogen. Ammonia is used to make nitrogen compounds that are used as fertilliser by farmers

Question 18

What is denitrification?

Answer 18

Nitrogen compounds in living things are returned to the soil by denitrifying bacteria present in soil break down nitrogen compounds are release

Question 19

Give three example of non-living indicators that can measure environmental changes?

Answer 19

Nitrate levels, temperature and carbon dioxide levels.

Question 20

Identify a living indicators and describe how they can be used to measure climate and environmental change?

Answer 20

-bushy lichens need really clean air
-leafy lichens can survive a small amount of air pollution
-crusty lichens can survive in more polluted air.
-In places where no lichens are growing, it is often a sign that the air is heavily polluted with sulfur dioxide.
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Question 21

Approximately, when did life on earth begin?

Answer 21

3500 million years ago

Question 22

Describe the term variation?

Answer 22

Variation is all the differences which exist between members of the same species

Question 23

What causes genetic variation?

Answer 23

Mutations in the genes

Question 24

How can mutations be passed on to offspring?

Answer 24

If the mutated gene is present in one of the sex cells that makes a zygote.

Question 25

Describe the process of natural selection?

Answer 25

• There is genetic variation within organisms of the same species
• Some organisms will survive more successfully
• These organisms will live long enough to reproduce
• The successful characteristics will be passed to offspring who will continue to display the beneficial characteristics.

Question 26

Describe the difference between selective breeding and natural selection?

Answer 26

Natural selection and selective breeding can produce changes in animals and plants. The difference between the two is that natural selection occurs in nature, but selective breeding only occurs when humans intervene.
Selective breeding is a process where we choose the characteristics we want in a an animal or plant. We then breed together a male and female showing those characteristics.From the offspring produced we select those that show the characteristics the most and breed them together.

Question 27

Identify four factors that can produce new species in the process of evolution?

Answer 27

Mutations, environmental changes , natural selection and isolation.

Question 28

What provides evidence for evolution?

Answer 28

Fossil record and analysis of similarities and difference in the DNA

Question 29

What was Lamarck’s theory and why was Darwin’s theory of evolution by natural selection a better scientific explanation?

Answer 29

• Lamarck suggested the inheritance of characteristics acquired throughout an animal lifetime
• There was no evidence or mechanisms for Lamarck’s idea
• Darwin’s theory fits with advances in the understanding

Question 30

Which two features are used to classify organisms?

Answer 30

Their physical features and their DNA

Question 31

What is kingdom in the classification of organisms

Answer 31

In biology, kingdom is the second highest taxonomic rank below domain. Kingdoms are divided into smaller groups called phyla

Question 32

Give two reason for why the classification of animals is important?

Answer 32

• It helps us to make sense of the enormous diversity of organisms on Earth
• It can show the evolutionary relationships between organisms

Question 33

What three factors contribute to ‘biodiversity’?

Answer 33

The number of different species , the range of different organisms and genetic variation within species

Question 34

Why is biodiversity important?

Answer 34

Biodiversity is important so we must use the earth in a sustainable way to ensure we maintain good level of biodiversity in living things and species.

Question 35

The rate of extinction of species is increasing; Explain why it is likely due to human activity?

Answer 35

As the human population has risen, the number of extinctions has also risen. There are also clear mechanisms to suggest a cause for this correlation ie deforestation destroys the habitats of some animals

Question 36

Maintaining biodiversity is important for sustainability; hat does sustainability mean?

Answer 36

It means meeting the needs of todays people without damaging the earth for future generations

Question 37

Why is large scale mono-culture crop production not sustainable?

Answer 37

Because it does not maintain biodiversity

Question 38

Explain why it is preferable to decrease the use of packaging (even if it is biodegradable) ?

Answer 38

Because energy used in the production and transport of packaging and because of slow decomposition in oxygen deficient landfill sites