Crop Genetics - Gene Segregation and Genetic Recombination

What does genetics study?

How traits are passed from parents to offspring through genes and chromosomes.

What is transmission (Mendelian) genetics?

The study of inheritance patterns, including gene segregation and recombination.

What is gene segregation?

The separation of allelic gene pairs during gamete formation.

During which process does segregation occur?

Meiosis, through the separation of homologous chromosomes.

How many alleles for a gene does each gamete receive?

One allele from each gene pair.

What happens to alleles at the same locus during meiosis?

They segregate into different gametes.

Why does segregation explain heterozygote inheritance?

Because each gamete carries only one of the two alleles.

What is Mendel’s Law of Independent Assortment?

Alleles of different genes assort independently into gametes if unlinked.

When do genes assort independently?

When they are on different chromosomes or far apart on the same chromosome.

What is the result of independent assortment?

All possible combinations of alleles from different loci can occur in gametes.

How does independent assortment affect genetic variation?

It increases variation among offspring.

What is genetic recombination?

The formation of new allele combinations different from those in either parent.

What is a recombinant offspring?

An individual with a genotype that does not match either parent.

How does recombination benefit plant breeding?

It allows beneficial traits from different parents to be combined.

What happens during meiosis I?

Homologous chromosomes pair, segregate, and independently assort.

What is crossing-over?

The physical exchange of chromosome segments between homologous chromosomes.

Where does chrossing-over occur?

At chiasmata during meiosis I.

What is the result of crossing-over?

New allele combinations within chromosomes.

Why are segregation and recombination important in breeding?

They generate genetic variation in breeding populations.

What do breeders do with recombinant individuals?

Select those combining desirable traits for future generations.

What genetic tools rely on segregation and recombination?

Mendelian crosses, Punnett squares, and genetic mapping.

Define segregation.

Separation of alleles into different gametes during meiosis.

Define independent assortment.

Independent inheritance of alleles from different genes (if unlinked).

Define recombination.

Creation of new allele combinations through crossing-over or independent assortment.

Define recombinant.

Offspring genotype that differs from both parents due to recombination.