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प्रश्न
A child has blood group O. If the father has blood group A and mother blood group B, work out the genotypes of the parents and the possible genotypes of the other offsprings.
उत्तर
If the father has blood group A, i.e., IAIA (homozygous), and the mother has blood group B, i.e., IBIB (homozygous), all offsprings will have blood group AB (IAlB) rather than blood group O.
A child has blood group O only if both parents are heterozygous, i.e. father IAIi and mother IBIi.
Therefore, the parents of a child with blood group O will have genotypes IAi and IBi. Aside from O blood group offspring, there is a chance of three other blood groups. They are IAi (blood group A), IBi (blood group B), and IAIB (blood group AB).
Notes
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संबंधित प्रश्न
Differentiate between the following -
Dominance and Recessive
Differentiate between the following -
Monohybrid and Dihybrid.
When a cross in made between tall plant with yellow seeds (TtYy) and tall plant with green seed (Ttyy), what proportions of phenotype in the offspring could be expected to be
- Tall and green.
- Dwarf and green.
How would you find out whether a given tall garden pea plant is homozygous or heterzygous? Substantiate your answer with the help fo Punnett squares.
Given below are the F2 – phenotypic ratios of two independently carried monohybrid crosses :
(i) 1 : 2 : 1
(ii) 3 : 1
Mention what does each ratio suggest.
Mention whether the cross is a monohybrid or dihybrid.
Answer the following question.
Write the basis on which Alfred Sturtevant explained gene mapping.
What is a monohybrid cross? How did Mendel perform this cross?
A certain couple got four daughters in a sequence and no son. Does it mean that the husband does not produce Y-chromosome bearing sperms? Explain. What is the chance of this couple having a daughter?
What do you understand by the terms phenotype and genotype?
Pure-bred tall pea plants are first crossed with pure-bred dwarf pea plants. The pea plants obtained in the F1 generation are then selfed to produce F2 generation of pea plants.
What is the ratio of tall plants to dwarf plants in the F2 generation?
Differentiate between inherited and acquired characters. Give one example for each type.
Give reasons why acquired characters are not inherited.
Cross between hybrid and recessive parent:
In a monohybrid cross of plants with red and white flowered plants, Mendel got only red-flowered plants. On self-pollinating these F1 plants got both red and white flowered plants in 3:1 ratio. Explain the basis of using RR and rr symbols to represent the genotype of plants of parental generation.
Pooja has green eyes while her parents and brother have black eyes. Pooja’s husband Ravi has black eyes while his mother has green eyes and father has black eyes.
a. On the basis of the above given information, is the green eye colour a dominant or recessive trait? Justify your answer
b. What is the possible genetic makeup of Pooja’s brother’s eye colour?
c. What is the probability that the offspring of Pooja and Ravi will have green eyes? Also, show the inheritance of eye colour in the offspring with the help of a suitable cross.
OR
c. 50% of the offspring of Pooja’s brother are green eyed. With help of cross show how this is possible.
Assertion (A): In humans, if gene (B) is responsible for black eyes and gene (b) responsible for brown eyes, then the colour of eyes of the progeny having gene combination Bb, bb or BB will be black only.
Reason (R): The black colour of the eyes is a dominant trait.
