Agronomy Plant Genetics and Breeding

Question 1

What is a hybrid variety in crop production?

Accepted Answer

The F1 offspring of two inbred parent lines

Answer

A variety developed through genetic mutation

Answer

A variety adapted to tropical climates

Answer

An open-pollinated landrace variety

Question 2

What is 'heterosis' (hybrid vigor) in plant breeding?

Accepted Answer

Superior performance of F1 hybrids over parental averages

Answer

Reduced yield in hybrid offspring

Answer

Genetic uniformity in a population

Answer

Resistance to cross-pollination

Question 3

Which breeding method is most commonly used to develop new inbred lines for hybrid corn production?

Accepted Answer

Selfing (self-pollination) for multiple generations

Answer

Mass selection

Answer

Backcrossing

Answer

Mutation breeding

Question 4

What does the term 'quantitative trait' mean in plant genetics?

Accepted Answer

A trait controlled by many genes showing continuous variation

Answer

A trait controlled by a single dominant gene

Answer

A trait visible only in recessive plants

Answer

A trait unaffected by the environment

Question 5

Backcrossing in plant breeding is primarily used to do what?

Accepted Answer

Transfer a single trait into an elite variety while preserving its background

Answer

Increase genetic diversity

Answer

Create new inbred lines

Answer

Induce polyploidy

Question 6

GMO crops produced using Agrobacterium-mediated transformation are transformed how?

Accepted Answer

By inserting foreign DNA via the Ti plasmid into plant cells

Answer

By exposing seeds to radiation

Answer

By chemical mutagenesis of pollen

Answer

By grafting onto transgenic rootstocks