F2 generation in a Mendelian cross showed that both genotypic and phenotypic ratios are same as 1:2:1. It represents a case of
(1) codominance
(2) dihybrid cross
(3) monohybrid cross with complete dominance
(4) monohybird cross the incomplete dominance
Mutations can be induced with
(1) IAA
(2) ethylene
(3) gama radiations
(4) infra red radiations
Which one of the following cannot be explained on the basis of Mendel's Law of Dominance?
(1) The discrete unit controlling a particular character is called a factor
(2) Out of one pair of factors one is dominant, and the other is recessive
(3) Alleles do not show any blendings and both the characters recover as such in F2 generation.
(4) Factors occur in pairs
The genotype of a plant showing the dominant phenotype can be determined by
(1) test cross
(2) dihybrid cross
(3) pedigree analysis
(4) back cross
ABO blood groups in humans are controlled by the gene I. It has three alleles — IA, IB and i. Since there are three different alleles, six different genotypes are possible. How many phenotypes can occur?
(1) Three
(2) One
(3) Four
(4) Two
Select the correct statement from the ones given below with respect to dihybrid cross.
(1) Tightly linked genes on the same chromosome show higher recombinations
(2) Genes far apart on the same chromosome show very few recombinations
(3) Genes loosely linked on the same chromosome show similar recombinations as the tightly linked ones
(4) Tightly linked genes on the same chromosome show very few recombinations.
Which one of the following symbols and its representation, used in human pedigree analysis is correct?
(1) = Marriage between relatives
(2) = Unaffected male
(3) = Unaffected female
(4) = Male affected
Study the pedigree chart given below
What does it show?
1. | Inheritance of a sex-linked inborn error of metabolism like phenylketonuria |
2. | Inheritance of a condition like phenylketonuria as an autosomal recessive trait |
3. | The pedigree chart is wrong as this is not possible |
4. | Inheritance of a recessive sex-linked disease like haemophilia |
Select the incorrect statement from the following
(1) linkage is an exception to the principle of independent assortment in heredity
(2) galactosemia is an inborn error of metabolism
(3) small population size results in random genetic drift in a population
(4) baldness is a sex limited trait
Which one of the following condition in human is correctly matched with its chromosomal abnormality/linkage?
(1) Klinefelter's syndrome—44 autosomes + XXY
(2) Colourblindness —Y-linked
(3) Erythroblastosis foetalis— X-linked
(4) Down syndrome—44 autosomes + XO