The Environment

Question 1

Give 4 ways a desert animal has adapted to hot dry conditions.

Answer 1

Large surface are compared to volume- lets desert animals lose more heat.
Efficient with water- Desert animals lose less water by producing small amounts of concentrate urine.
Good in hot conditions- They have very thin layers of body fat and a thin coat to help them lose body heat.
Camouflage- A sandy colour gives good camouflage- to help them avoid predators or sneak up on prey.

Question 2

Give 3 ways an Arctic animal has adapted to cold conditions.

Answer 2

1/ Small surface area compared to volume. They have a compact shape to keep their surface area to a minimum-this reduces heat loss.
2/Well insulated- a thick layer of blubber for insulation- this also acts as an energy store when food is scarce.
Thick hairy coats keep body heat in.
3/ Camouflage- Arctic animals have white fur to help them avoid predators or sneak up on prey.

Question 3

How have desert plants adapted to hot dry climates?

Answer 3

1/ Small surface area compared to volume- to prevent losing water vapour from the surface of the leaves. Cacti have spines instead of leaves.
2/ Water storage tissues, cacti can store water in its thick stem.
3/ They have roots which are widely spread out to collect water from far away areas.

Question 4

How are some plants and animals adapted to deter prey?

Answer 4

• armour- roses have thorns, tortoises have shells.
• produce poisons- bee’s and poison ivy.
• warning colours to scare off predators- wasps.

Question 5

What do animals compete for?

Answer 5

territory, food, water and mates.

Question 6

What do plants compete for?

Answer 6

light, space, water and minerals from the soil.

Question 7

How do lichens tell us how much pollution is in an area?

Answer 7

Some types of lichens are sensitive to the concentration of sulfur dioxide in the atmosphere, the number and type of lichen at a particular location will indicate how clean the air is e.g the air is clean if there are lots of lichens.

Question 8

Why is less energy passed on as you go further up the food chain?

Answer 8

Energy is lost through movement of mammals and birds, energy is also lost through the organisms waste material.

Question 9

Describe the process of decay.

Answer 9

Plants take elements like carbon from the soil or the air an turn them into complex compounds, these are passed on when an animal eats the plant and continue through the food chain.
When the organism produces waste or when the organism dies
the elements are returned to the environment, these materials decay because they’re broken down by micro-organisms and put back into the soil.

Question 10

In what condition do micro organisms work best

Answer 10

warm, moist conditions with plenty of oxygen.

Question 11

How many pairs of chromosomes does the human cell nucleus contain?

Answer 11

23

Question 12

What do chromosomes carry?

Answer 12

Chromosomes carry genes, different genes control the development of different characteristics.

Question 13

Give 3 features of sexual reproduction.

Answer 13

• involves two parents
• involves the fusion of male and female gametes
• the offspring contain a mixture of their parents genes.

Question 14

Give 3 features of asexual reproduction.

Answer 14

• only one parent
• there’s no fusion of gametes
• the offspring are genetically identical to the parent- they’re clones.

Question 15

Explain the process of embryo transplants.

Answer 15

sperm cells are taken from one prize animal (bull)
egg cells are taken from another prize animal (cow)
They are artificially fertilised, the embryo that develops is then split many times before any cells become specialised.
These cloned embryos can then be implanted into lots of host mother, the offspring will all be genetically identical to each other.

Question 16

Explain the process of adult cell cloning.

Answer 16

• remove the genetic material (the nucleus) from an un fertilised egg cell.
• A full set of chromosomes from a human cell are taken and inserted into an ‘empty’ egg.
• The egg cell is then stimulated with an electric shock- causing the egg to divide .
  The embryo’s is implanted into the host mother when they are balls of cells to grow into a genetically identical copy of the original adult body cell.

Question 17

Explain the process of genetic engineering

Answer 17

A useful gene from an organisms chromosome is identified and cut out of the chromosome using restriction enzymes.
A chromosome from another organism is cut open using enzymes and the useful gene is inserted into the chromosome using ligase enzymes.
The chromosome is inserted back into the organism.

Question 18

What are the PRO’s and CON’s of GM crops?

Answer 18

PRO’S
Can increase the yield of a crop.
could help people in developing nations who lack nutrition in their diet.
Effective- GM crops are grown elsewhere in the world without any problems.

CON’S
growing GM crops will affect the number of weeds and flowers and so the population of insects that live in and around the crops- reducing farmland biodiversity.
Transplanted genes may get out into the natural environment.
Not everyone thinks they’re safe- allergies.

Question 19

Explain Darwins theory of Evolution

Answer 19

Darwin’s idea was that organisms evolved through natural selection.
Individuals within a species show variation in their genes, those with characteristics that make them better adapted to the environment have a better chance of surviving and so are more likely to breed successfully. The useful characteristics are therefore more likely to be passed on to the next generation.

Question 20

Explain Lamarks theory of Evolution

Answer 20

Lamarks thought that organisms evolved through acquired characteristics. If an organism used a characteristic a lot then it would become more developed during its lifetime, these acquired characteristics would be passed on to the next generation.

Question 21

Is cloning a for of asexual or sexual reproduction?

Answer 21

Asexual because it only uses one parent (host mother) the offspring is genetically identical and it does not involve the fusion of gametes

Question 22

What is a mutation

Answer 22

A change in an organisms DNA

Question 23

What is a stable community?

Answer 23

The materials taken out of the soil and used are balanced by those that are put back in

Question 24

Why did not everyone agree with drawings theory?

Answer 24

Went against religious beliefs
Genes or inheritance had not been discovered yet
Not enough Evidence