Variation

Question 1

Genes determine the phenotype of an organism ? true or false?

Answer 1

False ? the environment also plays a role.

Question 2

What is variation within a population?

Answer 2

Differences in the characteristics of individuals in a population.

Question 3

State three causes of variation in a population.

Answer 3

1. Genes
2. The environment
3. A combination of both

Question 4

Within a population, there is normally very little genetic variation ? true or false?

Answer 4

False ? just look around you at humans

Question 5

What causes variation within a population?

Answer 5

Mutations.

Question 6

What is evolution?

Answer 6

A change in the inherited characteristics of a population over time through a process of natural selection which may result in the formation of a new species.

Question 7

True or false ? does the theory of evolution by natural selection state that all living things evolved from simple life forms more than three billion years ago?

Answer 7

True.

Question 8

Would the best organism within a species to survive and reproduce be:
a) the strongest?
b) the one which reproduces the fastest?
c) the best adapted to the environment?

Answer 8

c)

Question 9

Define ‘species’.

Answer 9

Organisms that can interbreed to produce fertile offspring.

Question 10

Define ‘natural selection’.

Answer 10

The process by which evolution takes place - Nature chooses those those with favourable characteristics (best suited to environment) to survive and reproduce, passing on their genes

Question 11

What is selective breeding?

Answer 11

The process by which humans breed plants and animals for particular genetic characteristics.

Question 12

Name two historic examples of selective breeding.

Answer 12

1. Breeding food crops from wild plants
2. Domesticating animals

Question 13

State four modern examples of selective breeding.

Answer 13

1. Disease resistance in food crops
2. Animals which produce more meat or milk
3. Domestic dogs with a gentle nature
4. Large or unusual flowers

Question 14

State a drawback to selective breeding.

Answer 14

Inbreeding ? some breeds are prone to disease or inherited defects (e.g. some pugs have breathing problems).

Question 15

What is genetic engineering?

Answer 15

The process which involves modifying the genome of an organism by introducing a gene from another organism to give a desired characteristic.

Question 16

State three traits plants might be genetically engineered to have.

Answer 16

1. Resistant to insect attack
2. Resistant to herbicides
3. Increased yields

Question 17

Give one example of the use of genetically engineered bacterial cells.

Answer 17

To produce useful substances such as human insulin to treat diabetes.

Question 18

How is a gene ?cut out? from the genome of one species and inserted the genome of another?

Answer 18

Using enzymes.

Question 19

Into what is the gene inserted?

Answer 19

A vector

Question 20

Give two examples of vectors used in genetic engineering.

Answer 20

A bacterial plasmid, a virus

Question 21

State two benefits of genetic engineering.

Answer 21

Improved growth rates/Increased yield/Increased food quality/Produce human proteins/enzymes as medicine

Question 22

State three concerns around genetically engineering plants.

Answer 22

1. Unknown effects on populations of wild flowers
2. Unknown effects on populations of insects
3. Some people feel the effects of eating GM crops on human health have not been fully explored