The mechanism that causes a gene to move from one linkage group to another is called
(1) inversion
(2) duplication
(3) translocation
(4) crossing-over
If a colourblind man marries a woman who is homozygous for normal colour vision, the probalility of their son being colourblind is
(1) 0
(2) 0.5
(3) 0.75
(4) 1
A tall true breeding garden pea plant is crossed with a dwarf true breeding garden pea plant. When the F1 plants were selfed the resulting genotypes were in the ratio of
(1) 1 : 2 : 1 :: Tall heterozygous : tall homozygous : Dwarf
(2) 3 : 1 :: Tall : Dwarf
(3) 3 : 1 :: Dwarf : Tall
(4) 1 : 2 : 1 :: Tall homozygous : Tall heterogygous : Dwarf
In a test cross involving F1 dihybrid flies, more parental-type offspring were produced than the recombinant type offspring. This indicates
(1) chromosomes failed to separate during meiosis
(2) the two genes are linked and present on the same chromosome
(3) both of the characters are controlled by more than one gene
(4) the two genes are located on two different chromosomes
Match the terms in Column I with their description in Column II and choose the correct option.
Column I |
Column II |
A. Dominance |
1. Many genes govern a single character |
B. Codominance |
2. Ina heterozygous organism only one allele expresses itself |
C. Pleiotropy |
3. In a heterozygous organism both alleles express themselves fully |
D. Polygenic inheritance |
4. A single gene influences many characters |
Codes :
|
A |
B |
C |
D |
(1) |
2 |
3 |
4 |
1 |
(2) |
4 |
1 |
2 |
3 |
(3) |
4 |
3 |
1 |
2 |
(4) |
2 |
1 |
4 |
3 |
Which of the following most appropriately describes haemophilia?
(1) X-linked recessive gene disorder
(2) Choromosomal disorder
(3) dominant gene disorder
(4) Recessive gene disorder
The term "linkage" was coined by :-
1. TH Morgan
2. T Boveri
3. G Mendel
4. W Sulton
In the following human pedigree, the filled symbols represent the affected individuals. Identify the type of given pedigree
1. Autosomal dominant
2. X-linked recessive
3. Autosomal recessive
4. X-linked dominant
Multiple alleles are present
1. on different chromosomes
2. at different loci on the same chromosome
3. at the same locus of the chromosome
4. on non-sister chromatids
An abnormal human baby with 'XXX' sex chromosomes was born due to
1. formation of abnormal sperms in the father
2. formation of abnormal ova in the mother
3. fusion of two ova and one sperm
4. fusion of two ova and two sperm