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प्रश्न
Differentiate between the following:
Dominance and Recessive
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उत्तर
| Sr. No. | Dominance | Recessive |
| 1. | The dominant allele may reveal itself even in the presence of the recessive gene. | A recessive allele or factor cannot express its effect in the presence of a dominant allele. |
| 2. | It does not require another similar allele to influence the phenotype; for example, Tt is tall. | It has a phenotypic effect solely in the presence of an equivalent allele, such as tt, which is dwarf. |
| 3. | Dominant alleles or factors can create full polypeptides or enzymes that express their effects, such as the red colour of pea flowers. | The recessive allele produces an incomplete or faulty polypeptide or enzyme, resulting in the absence of the effects of the dominant allele, such as a white flower colour in peas. |
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संबंधित प्रश्न
Differentiate between the following:
Homozygous and Heterozygous
A child has blood group O. If the father has blood group A and the mother has blood group B, work out the genotypes of the parents and the possible genotypes of the other offspring.
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.
Explain Mendel’s monohybrid progeny with the help of any one cross.
Mention whether the cross is a monohybrid or dihybrid.
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?
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?
What do you understand by the terms phenotype and genotype?
A pure tall plant (TT) is crossed with the pure dwarf plant (tt), what would be the F1 and F2 generations? Explain.
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 do the plants of the F1 generation look like?
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.
Genotypic ratio of a monohybrid cross is ______.
A Monohybrid cross is ______
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?
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.
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.
Given below is a schematic representation of the inheritance of the shape of the seeds of garden peas. Answer the questions that follow:
- Which is the dominant and recessive allele of the trait?
- What does the ratio 3 : 1 in the F2 generation represent?
- State Mendel's Law of Dominance.
