Morgan observed tight linkage in Drosophila with only 1.3 percent recombination for
1. White eye and yellow body
2. Normal wing and yellow body
3. White eye and miniature wing
4. Yellow body and miniature wing
Morgan coined the term recombination to describe
1. Physical association of genes on a chromosome
2. Generation of new traits by mutation
3. Linkage of two genes on different chromosomes
4. Generation of non-parental gene combinations
Which of the following is a non-parental type of progeny obtained by Morgan while carrying out a dihybrid cross?
1.
2.
3.
4.
What percent of 'ab' type of gamete produced by a pea plant of genotype AaBb?
1. 25%
2. 50%
3. 75%
4. 100%
Mendel published his work on inheritance of characters in 1865 but it remained unrecognised till 1900 because :-
(a) | He could not provide any physical proof for the existence of factors |
(b) | His concept of factors as stable, discrete units that controlled the expression of traits did not find acceptance from the contemporaries |
(c) | Mendel's approach of using mathematics to explain biological phenomena was totally old |
(d) | Communication was not easy (as it is now) |
1. (a), (b) & (c) are correct
2. (c) & (d) are correct
3. (a), (b) & (d) are correct
4. Only (a) is correct
When a violet flower of unknown genotype is crossed with white flower, the progenies are violet and
white in equal proportion. Then read the following statements :
(i) This is called test cross.
(ii) Unknown flower is homozygous
(iii) Unknown flower is heterozygous
(iv) This test used to determine the phenotype of the plant at F2
(v) In test cross, violet or white flower is crossed with the recessive parent instead of self-crossing.
Select the incorrect statement.
1. iii, iv, v
2. ii, iv
3. i, ii, v
4. ii, iv, v
The unmodified (functioning) allele which represents the original phenotype is the allele and the modified allele is the allele.
1. (a) Recessive, (b) generally, (c) dominant
2. (a) dominant, (b) always, (c) recessive
3. (a) dominant, (b) generally, (c) recessive
4. (a) recessive, (b) always, (c) dominant
Read the following statements (A-D) :
(A) | Autosomal recessive trait can't be transmitted from normal parents to the offspring |
(B) | In mendelian cross, blending of alleles are observed at F1 generation |
(C) | Dominance is not an autonomous feature of gene or gene product |
(D) | Dominance is not universal |
Find which are only correct statements?
1. A & D
2. C & D
3. A, B & D
4. All are correct
Match column-I with column-II.
|
Column-I |
|
Column-II |
(a) |
Multiple alleles |
(i) |
Phenylketonuria in humans |
(b) |
Polygenes |
(ii) |
Blood groups in humans |
(c) |
Pleiotropy |
(iii) |
Skin color in human |
1. a-ii, b-i, c-iii
2. a-ii, b-iii, c-i
3. a-iii, b-ii, c-i
4. a-i, b-iii, c-ii
Sutton combined Cytological observation on meiotic cell division and Mendel's concept on inheritance
to propose.
1. Laws of inheritance
2. Chromosomal theory of inheritance
3. Law of segregation
4. Law of sex determination