Topic 6- Variation and Evolution

Question 1

What is variation

Answer 1

The differences in the charachteristics of individuals

Question 2

What are the causes of variation within a species

Answer 2

.Genetics
.Environment
.A mixture of both

Question 3

What is genetic variation

Answer 3

. Variations in the genotypes of organisms of the same species due to the presence of different alleles

Question 4

What creates genetic variation in a species

Answer 4

. Mutations
.Sexual reproduction

Question 5

What is a mutation

Answer 5

A random change in DNA

Question 6

What is a gene

Answer 6

A short sequence of DNA , that codes for specific sequence of amino acids , which folds to make a protein

Question 7

How may a gene mutation affect an organisms phenotype

Answer 7

. Mutation may cause a minor change in an organisms phenotype eg change in eye colour

Question 8

What is a phenotype

Answer 8

the physical charachteristics of an organism

Question 9

How may a gene mutation affect an organisms phenotype

Answer 9

Mutation may cause a minor change in an organisms phenotype . eg eye colour

Question 10

What is the consequence of a new phenotype caused by an mutation being suited to an environmental change

Answer 10

there will be a rapid change in species

Question 11

What is evolution

Answer 11

A gradual change in inherited traits within a population over time

Question 12

Outline the theory of natural selection

Answer 12

1. Within the same species there is genetic variation. This is due to mutations
2. Species compete for limited resources.
3. The most adaptive is able to complete successfully
4. Survivors can reproduce and pass on beneficial genes to the next generation

Question 13

How do two populations become different species

Answer 13

When there phenotypes become different to the extent that they can no longer produce fertile offspring

Question 14

What is selective breeding

Answer 14

the process by which humans breed plants and animals for desirable genetic charachteristics

Question 15

Identify the main steps of selective breeding

Answer 15

1. Parents with desirable genetic charachteristics are chosen from a population
2. The parent with desirable genetic charachterisitcs are bred together
3. Choose the offsrping with the desirable charachteristics and allow them to breed
4. Repeat for many generations

Question 16

Give examples of charachteristics for selective breeding

Answer 16

. Disease resistance in crops
.Higher milk or meat production in animals
.Gentle nature in domestic dogs
.Large flowers

Question 17

What is the main advantage of selective breeding

Answer 17

. Crops produce a higher yield of grain
.Cows produce greater supply of milk
.Plants produce larger fruit
.Domesticated animals

Question 18

Disadvantages of selective breeding

Answer 18

. Reduces variation
. .Likely to pass on inherited disorders
.Cannot adapt in environment. Could lead to extinction

Question 19

What is genetic engineering

Answer 19

Modifying the genome of an organism by introducing a gene from another organism to give a desired charachteristics.

Question 20

Give an example of uses for Genetically modified plants

Answer 20

.Disease resistance
.Produce larger fruits

Question 21

What is a use of genetically modified bacteria cells

Answer 21

.Bacteria produce human insullin
. disease resistance
. Herbicide resistance
(weedkillers)
.Pesticide resistance crops (insects,bugs)

Question 22

Describe the benefits of genetic engineering

Answer 22

. Increased crop yields for
growing population
.Useful in medicine
.GM crops produce scarce resources.eg vitiman A in body

Question 23

describe the risks of genetic engineering

Answer 23

.Long term affects of consumption of GM crops
.Negative environmental impacts
.Gm seeds are expensive
.Genetically modified crops will decrease variation

Question 24

What is the name for crops that had there genes modifed

Answer 24

Genetically modified GM crops.

Question 25

How is genetic engineering used to product crops against insects

Answer 25

. The gene for toxin production in Bt can be isolated and inserted into the Dna of crops

.Bt crops now secrete toxin which kills any insect larvae that feed on it

Question 26

What are the benefits of Bt crops

Answer 26

. Increased crop yields
.Lessens for the need for artificial insectides
.

Question 27

what is a vector

Answer 27

plasmid

Question 28

Steps for Genetic engineering for human insulin

Answer 28

1. Isolate the insulin Gene from human DNA
   2.Insert the DNA , into. vector such as plasmid
   3.Insert the Plasmid into a host bacterium
2. Let the bacteria divide and then produce insulin protien