Genetics

Monohybrid Cross

100

For each of the phenotypes, give me the genotypes. 

Curly hair (C) is dominant to straight hair (c). 

Straight? 

Curly? 

Curly: CC, Cc

Straight: cc

200

You cross a tall tomato plant (Tt) with a short tomato plant (tt). 

Genotypic Ratio? 

1:1

300

A heterozygous purple flower is crossed with a white flower.The purple trait is dominant. 

Phenotypic ratio? 

1:1

400

A guinea pig with short hair (L) is crossed to one that has long hair (l). Over a period of years, a scientist keeps records of the offspring and finds that 44 of them have short hair and 46 of them have long hair. Based on this data, what are the genotypes of the parents

Ll x ll because it is about a 1:1 ratio. 

Dihybrid Cross

100

G=grey hair 

g=white hair

B= black eyes 

b = red eyes

What is the phenotype of ggBB? 

White hair, black eyes

200

A grey haired, red-eyed male rabbit with the genotype GGbb is crossed with a white hair, black eyed female rabbit with the genotype ggBb. 

How many out of 16 would be grey, black-eyed? 

8 would be grey haired, black-eyed

300

For rabbits, the fur color and ear colors are...

B_  = black fur        E_ = long ears

bb =  brown fur        ee = floppy ears

A male rabbit with genotype BbEe x with a female rabbit with genotype bbee. 

Out of 16, how many have brown, floppy ears. 

4 out of 16/ 25%

400

Fruit flies are organisms commonly used in genetic studies. They reproduce quickly and have several easily observable traits.

One trait is the wings, which can be normal (dominant G) or vestigial (recessive g). Most flies have red eyes (E), but the sepia eye trait is recessive (e).

A fly that is heterozygous for both traits is crossed with a fly that has vestigial wings and sepia eyes (ggee). 

What is the phenotype ratio of the offspring?

( ___ normal wings/red eyes : ___ normal/sepia eyes : ___ vestigial wings/red : ___ vestigial/sepia)

1 normal wings/red eyes : 1 normal/sepia eyes : 1 vestigial wings/red : 1 vestigial/sepia

Complex Patterns of Inheritance

100

You find a flower whose phenotypes are red, white, and pink. What kind of inheritance is this? 

Incomplete dominance

200

You find a flower whose flower color is incomplete dominance with three phenotypes red, white, and pink. You cross a pink flower (C^RC^w) and a pink flower (C^RC^W). 

What is the phenotypic ratio? 

1:2:1

300

Flower phenotypes: 

C^RC^R = red C^RC^W= red and white spotted C^WC^W= white

You cross C^RC^R with C^RC^W. What is the genotypic and phenotypic ratio. 

Genotypic and phenotypic ratio= 2:2 (1:1)

400

Flower phenotypes: 

Red (C^RC^R), white (C^WC^W), and pink (C^RC^W) 

The phenotypic ratio of the offspring are 1 red: 2 pink: 1 white. What are the parents phenotypes? 

Both pink (C^RC^W)