Topic 2: Plant and Animal breeding

Question 1

Why does plant and animal breeding take place?

Answer 1

To improve characteristics to help support sustainable food production

Question 2

Breeders develop crops and animals with what properties?

Answer 2

Higher food yields,

higher nutritional values,

resistance to pests and diseases,

that thrive in particular environmental conditions

Question 3

What are the purpose of field trials?

Answer 3

To compare performance of different cultivars or treatments,

to evaluate GM crops

Question 4

Which factors have to be taken into account when designing a field trial?

Answer 4

Selection of treatments,

the number of replicates,

the randomisation of treatments

Question 5

The selection of treatments for field trials must be done in a way to ensure what?

Answer 5

The selection of treatments for field trials must be done in a way that ensures VALID COMPARISONS

Question 6

The number of replicates must take account of the _______ within the sample?

Answer 6

Variability

Question 7

What must the randomisation of treatments due when measuring treatment effects?

Answer 7

Eliminate bias

Question 8

What is the definition of inbreeding?

Answer 8

In inbreeding, selected related plants or animals are bred for several generations until the population breeds due to the desired type

Question 9

In inbreeding, what is eliminated?

Answer 9

The population breeds true because inbreeding eliminates heterozygotes

Question 10

What does inbreeding cause?

Answer 10

Inbreeding causes an increase in the frequency of individuals who are homozygous for the recessive, deleterious alleles

Question 11

What happens to the individuals with recessive, deleterious alleles?

Answer 11

Will do less well at surviving to reproduce

Question 12

How does inbreeding depression arise?

Answer 12

From the increased frequency and homozygous, recessive deleterious alleles

Question 13

Why are self pollinating plants less susceptible to inbreeding depression?

Answer 13

They are naturally inbreeding and less susceptible to inbreeding depression due to the elimination of deleterious alleles by natural selection

Question 14

How current patterns of inheritance in inbreeding be analysed?

Answer 14

Using monohybrid crosses

Question 15

Animals from different breeds may produce what?

Answer 15

A new crossbreed population

Question 16

A new cross breed population may have what?

Answer 16

Improve characteristics

Question 17

How can you alleles be introduced into a plant or animal lines?

Answer 17

By crossing a cultivar or breed with an individual with a different, desired genotype

Question 18

Implants, how are F1 hybrids produced?

Answer 18

Crossing two different inbred lines to create a relatively uniform heterozygous crop

Question 19

What is the benefit of F1 hybrids?

Answer 19

Increased vigour and yields

Question 20

In inbreeding why are animals and plants usually not bred together in F1?

Answer 20

Because the F2 produced shows too much variation

Question 21

What can happen as a result of genome sequencing?

Answer 21

Organisms with desirable genes can be identified and then used in breeding programs

Question 22

Breeding programs can involve crop plants with what properties?

Answer 22

Can involve crop plants that have been genetically modified using recombinant DNA technology

Question 23

In genetic technology what happens to the single genes that have the desirable characteristics?

Answer 23

Single gene is for desirable characteristics are inserted into the GM crop plants, to create GM plants with improved characteristics

Question 24

What are some examples of recombinant DNA technology in plant breeding?

Answer 24

• Insertion of BT toxin gene into plants for pest resistance,
• Glyphosate resistant gene inserted for herbicide tolerance