Short Answer TypeWhat are 'true breeding lines' that are used to study inheritance pattern of traits in plants?
How does the gene 'I' control ABO blood groups in humans? Write the effect the gene has on the structure of red blood cells.
Write the types of sex-determination mechanisms the following crosses show. Give an example of each type
(i) Female XX with Male XO
Write the types of sex-determination mechanisms the following crosses show. Give an example of each type
(ii) Female ZW with Male ZZ
A colour-blind child is born to a normal couple. Work out a cross to show how it is possible. Mention the sex of this child.
Mendel published his work on inheritance of characters in 1865, but it remained unrecognized till 1900. Give three reasons for the delay in accepting his work.
A geneticist interested in studying variations and patterns of inheritance in living beings prefers to choose organisms for experiments with shorter life cycle. Provide a reason.
A teacher wants his/her students to find the genotype of pea plants bearing purple coloured flowers in their school garden. Name and explain the cross that will make it possible.
Purple colour is a dominant phenotype in pea plants. To determine the genotype of the pea plant with purple flowers the students can use the process of Test cross. In test cross the pea plant whose genotype is to be determined is crossed with a homozygous recessive parent (pp) having white flowers. The test cross help the students to determine whether the genotype of the plant is heterozygous dominant (Pp) or homozygous dominant (PP).
So the Pea plant with an unknown genotype i.e. Px that can be either Pp or PP is crossed with homozygous recessive parent i.e. pp.
If half of the flowers are purple and the other half is white then the genotype of the plant is heterozygous dominant that is Pp
If all the flower produced after the cross are purple then the genotype would be PP homozygous dominant.
Long Answer TypeShort Answer TypeIn a cross between two tall pea plants some of the off-springs produced were dwarf. Show with the help of Punnett square how this is possible.
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