Variation

Question 1

What is variation

Answer 1

Differences in characteristics of individuals in a population

Question 2

What can cause variation

Answer 2

Genetic causes, environmental causes, and a combination of genes and the environment

Question 3

How do new phenotype variants occur

Answer 3

Mutations

Question 4

What is selective breeding

Answer 4

Breeding plants and animals for particular characteristics

Question 5

Describe the process of selective breeding

Answer 5

Choose parents with desired characteristics

Breed them together

Choose offspring with the desired characteristics and breed again

Continue over many generations until all offspring show the desired characteristics

Question 6

What are the consequences of inbreeding

Answer 6

Inherited defects and disease

Question 7

What is genetic engineering

Answer 7

Modifying the genome of an organism by introducing a gene from another organisms to give a desired characteristic

Question 8

Why have plant crops been genetically engineered

Answer 8

To be resistant to diseases/herbicides/ pesticides
To produce bigger fruits
Higher yields

Question 9

Why have bacteria been genetically engineered

Answer 9

To produce useful substances such as insulin to treat diabetes

Question 10

What are enzymes used for in genetic engineering

Answer 10

Cut out the required gene

Question 11

What is used to transfer the required gene into the new cell in genetic engineering

Answer 11

Vector

Bacteria plasmid or virus

Question 12

Describe the steps involved in adult cell cloning

Answer 12

Nucleus removed from unfertilised egg cell

Nucleus from adult body cell inserted into egg cell

Electric shock stimulates egg cell to divide to form an embryo

Embryo develops and is inserted into the womb of the adult female

Question 13

What is tissue culture cloning

Answer 13

Using small groups of cells from plants to grow identical new plants

Question 14

Why is tissue culture cloning of plants important

Answer 14

Preserve rare species and for growing plants commercially in nurseries

Question 15

What is cutting as a cloning method

Answer 15

Simple method used by gardeners to produce many identical plants from a parent plant

Question 16

Describe cloning through using embryo transplants

Answer 16

Cells split apart from a developing animal embryo before they are specialised then the identical embryos are transplanted into host mothers

Question 17

Why is selective breeding used

Answer 17

Disease resistance in food crops

Animals that produce more meat or milk

Domestic dogs/cats with gentle nature

Larger or unusual flowers

Question 18

What are the disadvantages of selective breeding

Answer 18

Can lead to inbreeding

Reduces variation so whole species can be at risk to same disease

Question 19

What is a clone

Answer 19

An individual that has been produced asexually and is genetically identical to its parent

Question 20

Benefits of cloning

Answer 20

Large number of identical offspring produced

Quick and economical

Desired characteristics guaranteed

Question 21

Risks of cloning

Answer 21

Limits variation and causes reduction in gene pool

Clones may be vulnerable to disease or changed to the environment

Ethical consideration around cloning living organisms

Question 22

Explain process of genetic engineering

Answer 22

Cell from organism with desired gene

Enzymes used to cut out the desired gene

Cell with vector

Vector taken out of cell and split open

Gene removed is inserted into the vector

Vector is used to insert gene into required cell at an early stage in development

As the organism grows it develops with the desired characteristics from the other organism

Question 23

What are the benefits of genetic engineering

Answer 23

Potential to overcome some inherited human diseases

Can lead to high value of crops as GM crops have higher yields

Crops can be engineered to be resistant to herbicides, make their own pesticides, or be more resistant to environment

Question 24

What are the risks of genetic engineering

Answer 24

Genes from GM plants and animals may spread to other wildlife causing harm

May have negative impacts on populations of wild flowers and insects

Ethical concerns - people may manipulate genes of children

Long term effects of heath when eating GM crops have not been fully explored