Which one of the following is an example of polygenic inheritance?
Flower colour in Mirabilis jalapa
Production of male honey bee
Pod shape in garden pea
Pod shape in garden pea
D.
Pod shape in garden pea
Polygenic inheritance involves the determination of a particular phenotypic characterisitc by many genes, called polygenes (i.e., the group of genes influencing a quantitative characteristic), each having a small effect individually.
The characteristics controlled in this way show continuous variation and are called polygenic characters e.g., height and skin colour in humans.
The polygenic inheritance is called multifactorial inheritance or quantitative inheritance.
The pink flower colour in Mirabilis jalapa is an example of incomplete dominance while production of male honey bee is an example of parthenogenesis.
A common test to find the genotype of a hybrid is by
crossing of one F2 progeny with male parent
crossing of one F2 progeny with female parent
studying the sexual behaviour of F1 progenies
studying the sexual behaviour of F1 progenies
Two genes R and Y are located very close on the chromosomal linkage map of a maize plant. When RRYY and rryy genotypes are hybridised, the F2 segregation will show:
higher number of the recombinant types.
segregation in the expected 9 : 3 : 3 : 1 ratio
segregation in 3 : 1 ratio
segregation in 3 : 1 ratio
In pea plants, yellow seeds are dominant to green. If a heterozygous yellow seeded plant is crossed with a green seeded plant, what ratio of yellow and green seeded plants would you expect in F1 generation?
50:50
9:1
1:3
1:3
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?
AaBb
AaBB
AABb
AABb
Which one of the following is the most suitable, medium for culture of Drosophila melanogaster?
Moist bread
Agar agar
Ripe banana
Ripe banana
In Mendel's experiments with garden pea, round seed shape (RR) was dominant over wrinkled seeds (rr), yellow cotyledon (YY) was dominant over green cotyledon (yy). What are the expected phenotypes in the F2 generation of the cross RRYY x rryy?
Only round seeds with green cotyledons
Only wrinkled seeds with yellow cotyledons
Only wrinkled seeds with green cotyledons
Only wrinkled seeds with green cotyledons
Haploids are more suitable for mutation studies than the diploids. This is because
Haploids are reproductively more stable than diploids
mutagens penetrate in haploids more effectively than is diploids
haploids are more abundant in nature than diploids
haploids are more abundant in nature than diploids
Inheritance of skin colour in humans is an example of
chromosomal aberration
point mutation
polygenic inheritance
polygenic inheritance
Phenotype of an organism is the result of
mutations and linkages
cytoplasmic effects and nutrition
environmental changes and sexual dimorphism
environmental changes and sexual dimorphism
