Which one of the following is an example of polygenic inheritance ?

(1) Flower colour in Mirabilis jalapa 

(2) Production of male honey bee

(3) Pod shape in garden pea

(4) Skin colour in humans

Test cross involves :

(1) crossing between two geneotypes with recessive trait

(2) crossing between two F₁ hybrids

(3) crossing the F₁ hybrid with a double recessive genotype

(4) crossing between two genotypes with dominant trait

Sickle cell anaemia has not been eliminated from the African population because :

(1) it is controlled by recessive genes

(b) it is not a fatal disease

(3) it provides immunity against malaria

(4) it is controlled by a dominant genes

How many different kinds of gametes will be produced by a plant having the genotype AABbCC ?

(1) Three

(2) Four

(3) Nine

(4) Two

A common test to find the genotype or hybrid is by :

(1) crossing of one F₂ progeny with male parent

(2) crossing of one F₂ progeny with female parent

(3) studying the sexual behaviour of F₁ progenies

(4) crossing of one F₁ progeny with recessive parent

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

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

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

Study the pedigree chart given below

What does it show?

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