Mendel

Question 1

What is True-breeding?

Answer 1

Organisms that are either homozygous dominant or homozygous recessive for their trait

Question 2

When true-breeding parents cross in hybridization, they produce _____________.

Answer 2

Monohybrids

Heterozygous F1 generation

Question 3

What is the result of a Monohybrid Cross?

Answer 3

The F2 generation

Offspring of heterozygous x heterozygous

Question 4

What is position-effect variegation?

Answer 4

When gene expression is altered due to positioning of a gene, whether it be located on the euchromatic region or the heterochromatic region.

Question 5

If the allele for Wild type red eyes is located on euchromatic DNA (less compact), would you expect to see the red eyes expressed or silenced?

Answer 5

Expressed

Question 6

Are genes expressed or silenced on heterochromatic regions?

Answer 6

Silenced

Question 7

What is constitutive heterochromatin?

Answer 7

Chromosome regions where the chromatin is always densely compacted

Eg, the centromere

Question 8

What is facultative heterochromatin?

Answer 8

Chromosome regions where the chromatic switches back and forth between euchromatic and heterochromatic.

These genes can be expressed

Question 9

There are two types of mutations that affect heterochromatin, what are they?

Answer 9

E(var) mutations - enhancers that produce proteins that encourage the spread of heterochromatin

Su(var) mutations - suppressors they produce proteins that restrict the spread of heterochromatin