Lecture 12

Question 1

What controls inheritance

Answer 1

Chromosomes

Question 2

Name the basis of plant breeding

Answer 2

Mendel’s Laws

Question 3

How are sexually reproducing plants pollinated

Answer 3

•Self Pollinated
•Cross Pollinated

Question 4

What are the main steps of breeding

Answer 4

•Collection
•selection
•crossing
•evaluation
•introduction

Question 5

What does Gene Transformation allow

Answer 5

Transfer of one or several genes

Question 6

How does reproduction occur in plants

Answer 6

Via Seeds

Question 7

Where is the chromosome located

Answer 7

Nucleus

Question 8

What do genes determine

Answer 8

Metabolic activities of the cell

Question 9

What are genes composed of

Answer 9

Nucleotides
Who’s sequence dictates the sequence of amino acids during protein synthesis

Question 10

What are chromosomes made of

Answer 10

DNA

Question 11

What is meiosis

Answer 11

cell division that reduces the genetic content by HALF

Question 12

Why is meiosis necessary

Answer 12

to enable sexual reproduction (50% of each parent)

Question 13

What are different forms of a gene called

Answer 13

Alleles

Question 14

What 3 factors is Mandelian Genetics law of inheritance based on

Answer 14

•Genetic characters are controlled by two alleles
•One allele determines the phenotype observed for that trait
•One of the chromosomes from the parent will be passed on randomly to each of the gametes

Question 15

Explain Qualitative traits

Answer 15

–Easily separated into distinct classes
–Controlled by one or few genes
–E.g., green or yellow pods in pea plants

Question 16

Explain Quantitative traits

Answer 16

–Not easily separated into classes
–Controlled by many genes
–E.g., height and growth rate

Question 17

Explain breeding in self pollinated plants

Answer 17

–Usually homozygous
–Common methods of breeding include pedigree selection or mass selection - wheat etc

Question 18

Explain breeding in cross pollinated plants

Answer 18

–Heterozygous
–Can use mass selection
–Hybridization most commonly used

Question 19

Explain Breeding by Pedigree Selection

Answer 19

•Seed from F1 generation is planted; superior plants are selected
•Seed from selected plants will be collected and planted in rows; undesirable plants discarded
•Additional selection within rows occurs with additional planting of selected seed as many as six times, to the F6 generation
•At the F6 generation, plant rows become uniform, and seeds from selected rows can be bulked and evaluated in yield trials

Question 20

Explain Breeding by Hybridisation

Answer 20

•Corn inbreds developed by self-pollinating selected corn plants for several generations to make a uniform variety
•Corn hybrid produced by crossing two inbred plants with distinct genetic traits
•This first hybrid produced, an F1 hybrid, typically has traits superior to those of either inbred parent - hybrid vigour / heterosis

Question 21

What is Genotype

Answer 21

The total genetic makeup

Question 22

What is Phenotype

Answer 22

due to genotype, the environment, and their interaction

Question 23

What is Heritability

Answer 23

proportion of phenotype controlled by genetic factors

Question 24

For Genetic transformation what does transfer occur via

Answer 24

•Bacterium
•Gene gun

Question 25

What is genetic transformation used for

Answer 25

qualitative traits like herbicide and disease resistance - GMO Crops

Question 26

A crop with more than one transgenic trait is called what

Answer 26

Stacked trait variety

Question 27

Benefits of genetically modified plants

Answer 27

•Crops’ resistance to pests
•Herbicide tolerance
•Adaptation to environmental stresses
•Desirable functional characteristics
•Desirable nutritional characteristics

Question 28

Concerns of Genetically modified plants

Answer 28

•Safety of genetically modified plants
•Impact on human health
•Outcrossing with weedy relatives
•Unintended effects on nontarget organisms
•Resistant pests
•Ethical and religious issues