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Question
Differentiate between the following:
Dominance and Recessive
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Solution
| 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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RELATED QUESTIONS
Differentiate between the following:
Monohybrid and Dihybrid
When a cross is 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:
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Given below are the F2 – phenotypic ratios of two independently carried monohybrid crosses :
(i) 1 : 2 : 1
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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?
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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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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.
