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प्रश्न
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.
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उत्तर
(a) Yes, green eye colour is recessive as it will express only in homozygous condition.
(b) BB, Bb
(c) bb*Bb
| B | b | |
| b | Bb | bb |
| b | Bb | bb |
Genetic cross - 50% of the offsprings can have green eye colour.
OR
(c) Brother is heterozygous (Bb) and wife is green (bb)
Wife bb*Bb brother
| B | b | |
| b | Bb | bb |
| b | Bb | bb |
50% of the offsprings can have green eye colour as per the cross shown.
APPEARS IN
संबंधित प्रश्न
Differentiate between the following:
Homozygous and Heterozygous
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.
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.
Which type of plants was missing in the F1 generation but reappeared in the F2 generation?
Give reasons why acquired characters are not inherited.
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.
In a plant tallness is dominant over dwarfness and red flower is dominant over white. Starting with the parents work out a dihybrid cross. What is standard dihybrid ratio? Do you think the values would deviate if the two genes in question are interacting with each other?
In a cross between red coloured and white coloured flowers, when plants with red coloured flowers of F1 generation were self pollinated, plants of F2 generation were obtained in which 75% of plants were with red flowers and 2.5% plants were with white flowers.
Explain the inheritance of traits in the above cross with the help of a flow chart only along with the ratio of plants obtained.
Mendel used a monohybrid cross to understand how which feature passes from parents to offspring?
What is the genotypic ratio in F2?
Which conclusion follows from the tall and dwarf pea plant monohybrid cross?
