Which one of the following symbols and its representation, used in the human pedigree analysis is correct?
1. | = Mating between relatives |
2. | = Unaffected male |
3. | = Unaffected female |
4. | = male affected |
Sickle cell anaemia is:
1. | an autosomal linked dominant trait |
2. | caused by substitution of valine by glutamic acid in the globin chain of haemoglobin |
3. | caused by a change in base pair of DNA |
4. | characterized by elongated sickle like RBCs with a nucleus |
Point mutation involves:
1. insertion
2. change in single base pair
3. duplication
4. deletion
Study the pedigree chart given below:
What does it show?
1. | Inheritance of a sex-linked inborn error of metabolism |
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 result in random genetic drift in a population |
4. | baldness is a sex-limited trait |
A human male produces sperms with the genotypes AB, Ab, aB and ab pertaining to two diallelic characters in equal proportions. What is the corresponding genotype of this person?
1. AaBb
2. AaBB
3. AABb
4. AABB
In hexaploid wheat, the haploid (n) ar basic (x) numbers of chromosomes are:
1. n=7 and x=21
2. n=21 and x=21
3. n=21 and x=14
4. n=21 and x=7
1. | Klinefelter's syndrome-44 autosomes + XXY |
2. | Colourblindness – Y-linked |
3. | Erythroblastosis foetalis-- X-linked |
4. | Down syndrome--44 autosomes + XO |
Inheritance of skin colour in humans is an example of:
1. chromosomal aberration
2. point mutation
3. polygenic inheritance
4. codominance
Two genes R and Y are located very close on the chromosomal linkage map of the maize plant. When RRYY and rryy genotypes are hybridized, then F2 segregation will show:
1. higher number of the recombinant types
2. segregation in the expected 9:3:3:1 ratio
3. segregation in a 3:1 ratio
4. higher number of the parental types