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Black fur is dominant to brown fur in rabbits. If a farmer has a black rabbit, w

ID: 14148 • Letter: B

Question

Black fur is dominant to brown fur in rabbits. If a farmer has a black rabbit, what can he do to figure out if it is purebred or hybrid? Design an experiment that would help him figure tins out. x** Achondroplastic dwarfism is a dominant trait in humans. Two dominant alleles is a lethal genotype What is the probability of two dwarf people having a normal child? ** A normal woman and a dwarf m an plan to have children What is the probability of them having normal children?** Huntington's disease is caused by a dominant allele. Homozygous dominant is a lethal combination. People who inherit one dominant allele from a parent will develop the disease in middle age. It is fatal and there is no cure. Unfortunately, people usually have kids before they show symptoms. What are the chances that a person with Huntington's will pass the gene on to his or her kids? ( assume the partner is normal ) **

Explanation / Answer

Answer by conducting Test cross

B------BLACK ,b-brown

BB BLACK   x        bb brown

B

B

b

bB BLACK

bB BLACK

b

bB BLACK

bB BLACK

IF IT IS PURE HOMOZYGOUS PURE BRED ALL OSSFPRING ARE BLACK

                  Bb   BLACK   x        bb brown

B

b

b

bB BLACK

bb brown

b

bB BLACK

bb brown

IF IT IS heterozygous black ----------

- 50%       are OfFPRING ARE BLACK

- 50%       are OfFPRING ARE brown

===================

Normal   dd    x Heterozygous     Dd

D

d

d

Dd

Heterozygous ACHONDROPLASIA

dd

NORMAL

d

Dd

Heterozygous ACHONDROPLASIA

dd

NORMAL

Normal ----------child =50%

===================

Heterozygous     Dd x Heterozygous     Dd

D

d

D

DD LETHAL ELIMINATED

Dd

Heterozygous   ACHONDROPLASIA

d

Dd

Heterozygous ACHONDROPLASIA

Dd NORMAL

Normal ----------child = 25%

Heterozygous     Hh x Heterozygous     Hh

H

h

H

HHLETHAL ELIMINATED

Hh

Heterozygous   

h

Hh

Heterozygous

Hh

NORMAL

Answer ----50 %-of child will carry the genes

B

B

b

bB BLACK

bB BLACK

b

bB BLACK

bB BLACK