Chapter 8

Question 1

Designate letters to represent alleles: Dominant, recessive, codominant

Answer 1

Dominant = capital letter
Recessive = lower case
Codominance = superscript

Question 2

When conducting a dihybrid cross with two heterozygous individuals, the phenotypic ratio will always be?

Answer 2

9:3:3:1

Question 3

9:3:3:1 is a phenotypic ratio that occurs when…..

Answer 3

conducting a dihybrid cross with two heterozygous individuals

Question 4

What are unlinked genes?

Answer 4

Genes on different chromosomes or far apart on the same chromosome

Question 5

What are linked genes?

Answer 5

Genes close together on the same chromosome

Question 6

Are unlinked genes located on different chromosomes subject to Independent Assortment?

Answer 6

Yes

Question 7

Are unlinked genes located far apart on the same chromosome subject to Independent Assortment?

Answer 7

No

Question 8

What happens to unlinked genes located far apart on the same chromosome during Crossing Over?

Answer 8

There is a high chance of Crossing Over

Question 9

Are linked genes subject to Independent Assortment?

Answer 9

No

Question 10

What happens to linked genes during Crossing Over?

Answer 10

Low chance of Crossing Over

Question 11

The chances of Crossing Over occurring is calculated by what unit?

Answer 11

Map Units

Question 12

One map unit is what per cent chance of crossing over?

Answer 12

1%

Question 13

What are the 2 types of dihybrid crosses?

Answer 13

• Linked
• Unlinked

Question 14

How do you tell if a gene is linked or unlinked when crossing a heterozygote and a homozygous recessive?

Answer 14

Unlinked genes would have a phenotypic ratio of 1:1:1:1, linked genes would have a different ratio

Question 15

What are “recombinant genes” vs “parental genes”

Answer 15

If Crossing Over occurs = recombinant
If Crossing Over does not occur = parental