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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.
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
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.
Explain Mendel’s monohybrid progeny with the help of any one cross.
Mention whether the cross is a monohybrid or dihybrid.
Differentiate Between Monohybrid and Dihybrid cross.
A garden pea plant produces axial white flowers. Another of the same species produced terminal violet flowers. Identify the dominant trait?
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?
Cross between hybrid and recessive parent:
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.
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.
