Test cross involves:
1. | crossing between two genotypes 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 the trait |
If a colourblind woman marries a normal-visioned man, their sons will be:
1. all normal visioned
2. one-half colourblind and one-half normal
3. three-fourths colourblind and one-fourth normal
4. all colourblind
Cri-du-chat syndrome in humans is caused by the:
1. | fertilization of an XX egg by a normal y-bearing sperm |
2. | loss of half of the short arm of chromosome 5 |
3. | loss of half of the long arm of chromosome 5 |
4. | trisomy of 21st chromosome |
Sickle cell anaemia has not been eliminated from the African population because:
1. It is controlled by recessive genes
2. It is not a fatal disease
3. It provides immunity against malaria
4. It is controlled by dominant genes
Both sickle cell anaemia and Huntington’s chorea are:
1. bacteria-related diseases.
2. congenital disorders
3. pollutant-induced disorders
4. virus-related diseases
In Mendel's experiments with garden peas, round seed shape (RR) was dominant over wrinkled seeds (rr), and yellow cotyledon (YY) was dominant over green cotyledon (yy). What are the expected phenotypes in the F2 generation of the cross RRYY x rryy?
1. | Only round seeds with green cotyledons |
2. | Only wrinkled seeds with yellow cotyledons |
3. | Only wrinkled seeds with green cotyledons |
4. | Round seeds with yellow cotyledons and wrinkled seeds with yellow cotyledons |
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
How many different kinds of gametes will be produced by a plant having the genotype AABbCC?
1. Three
2. Four
3. Nine
4. Two
In which mode of inheritance do you expect more maternal influence among the offspring?
1. Autosomal
2. Cytoplasmic
3. Y-linked
4. X-linked
Phenotype of an organism is the result of:
1. mutations and linkages
2. cytoplasmic effects and nutrition
3. environmental changes and sexual dimorpgism
4. genotype and environment interactions