B3

Question 1

What is a species?

Answer 1

A group of organisms that can reproduce to create fertile offspring

Question 2

What is adaptation?

Answer 2

The adjustment to a habitat to ensure survival

Question 3

Animals and plants in a habitat are all part of one large system called a…

Answer 3

Food web

Question 4

Describe interdependance

Answer 4

The dependance of organisms on each other with the change of levels of one having a massive impact on the rest of the food web

Question 5

Name 3 ways do animals become extinct

Answer 5

By failing to adapt to a changing environment
Threat to habitat from humans
Introduction of a new species

Question 6

How is energy transferred along the food chain from the sun?

Answer 6

Plants absorb energy from the sun, and this energy is transferred through food chains as animals begin to consume each other

Question 7

How is energy lost along the food chain?

Answer 7

Some parts of organisms cannot be digested
Some energy is lost through respiration and movement
It can also be lost through excretion as waste products have energy

Question 8

How is energy transferred even after an organism dies?

Answer 8

Decomposers (fungi, bacteria) break organisms down into detritus (partly decayed material) and detritivores (worms, woodlice) eat it and break it down more

Question 9

Describe the carbon cycle

Answer 9

Carbon exists in the air mainly as carbon dioxide. Plants use this for photosynthesis. Carbon then passes into organisms as they eat plants. It is then returned to the air as carbon dioxide through respiration, the death of organisms (decomposers breaking them down respire) and combustion of organic materials

Question 10

How is nitrogen from the air transferred into soil?

Answer 10

Lightning and nitrogen fixing bacteria in the roots of legumes fix nitrogen in the soil

Question 11

How is nitrogen in the soil used?

Answer 11

It is absorbed by plants which is then passed on to animals that eat the plants

Question 12

How is nitrogen put back into the atmosphere?

Answer 12

The break down of dead organisms and faeces by bacteria turns it into ammonia, which is then turned into soil nitrates again by nitrifying bacteria. Then denitrifying bacteria in the boggy soil return the nitrates back into nitrogen in the air

Question 13

What are indicators of environmental change?

Answer 13

Non living indicators - carbon dioxide and nitrate levels or temperature
Living indicators - decreasing number of small organisms

Question 14

How can we see the development of organisms over millions of years?

Answer 14

Genetic variation and fossils

Question 15

How does evolution happen?

Answer 15

A mutation of a gene in an organisms’ sex cell can cause a new characteristic that can be passed on to offspring. This can continue to be passed on if reproduction occurs between organisms with this characteristic

Question 16

What is natural selection?

Answer 16

Organisms in environments may have different traits due to evolution. Organisms with a trait is useful will have a greater survival rate of animals that have the trait and therefore more likely to reproduce. Organisms failing to survive in the new habitat will die as off leaving a new species

Question 17

How can traits varying benefit organisms?

Answer 17

Make it easier to compete with other organisms - avoid prey, catch food, increase disease resistance

Question 18

What happens in the selective breeding process?

Answer 18

2 organisms with the same desirable trait are selected
They are bred to create offspring
Offspring that have this desirable trait are then bred with other organisms with same desirable trait
This goes on for several generations

Question 19

Evidence for evolution

Answer 19

Similarities in some parts of DNA sequencing in species showing they have a common ancestor
The simplest organisms are found in the earlier rocks and more complex organisms in newer rocks
DNA analysis today has confirmed that prediction made from fossils were correct

Question 20

Describe Darwin’s theory about variation in animals

Answer 20

Darwin said that random mutations in animals genetic occurred leaving to a new characteristics emerging in offspring and as the animal reproduces the trait is passed on. He called it the theory of evolution

Question 21

Describe Larmarck’s theory about variation in animals

Answer 21

Larmarck stated an animal adapted to its environment and passed on that trait to its offspring
e.g. giraffes grew long necks to reach plants higher up and then the giraffes offspring already had long necks when they were born

Question 22

Why is Darwin’s theory accepted over Larmarck?

Answer 22

There is evidence of the theory of evolution and not for Lamarck’s theory

Question 23

What is biodiversity?

Answer 23

The variety of life on Earth or in a habitat

Question 24

How can biodiversity be measured in a habitat?

Answer 24

The number of different species
The range of organisms (plants, animals, micro-organisms)
The genetic variation within each species

Question 25

What is a kingdom?

Answer 25

A large group of many organisms but few characteristic in common (e.g. mammals, reptiles)

Question 26

What is sustainability?

Answer 26

The ability to meet today’s needs without hindering future generations from meeting theirs

Question 27

How do we increase sustainability?

Answer 27

Maintaining biodiversity as all organisms are very dependant on each other
Limit our impact on wildlife and their habitats
Supporting ecosystems

Question 28

What is the Life Cycle Assessment?

Answer 28

The assessment that tracks the environmental impact of a product from:
sourcing raw material → manufacture → transport → use → disposal

Question 29

How can we increase the sustainability of a product manufacture?

Answer 29

Use as little energy and packaging as possible
Use more locally available materials
Create as little pollution as possible