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Question
Explain the Law of Dominance using a monohybrid cross.
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Solution
The law of dominance states that when a pair of alleles or allelomorphs are combined in an F1 hybrid, only one of them expresses itself, hiding the expression of the other. A monohybrid cross was used to investigate the simultaneous inheritance of a single pair of Mendelian components. A Monohybrid cross is one that considers only different versions of a single character. The feature that occurred in the F1 generation was referred to as dominant, whereas the trait that did not appear in the F1 population was known as recessive.
Thus, when a pair of alleles come together in an F1 hybrid, only one of them expresses itself, hiding the expression of the other entirely. In the above example, in the Tt - F1 hybrid (tall), only ‘T’ expresses itself as dominant, while ‘t’ remains hidden as recessive. This instance illustrates and indicates the law of dominance.
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RELATED QUESTIONS
If a hybrid expresses a character, is it called ______.
The allele which is unable to express its effect in the presence of another is called ______.
An allele is dominant if it is expressed in ______.
The characters which appear in the first filial generation are called ______.
Which of the following trait is controlled by dominant autosomal genes?
The best method to determine the homozygous and heterozygous of an individual is ______.
A pure tall pea was crossed with a pure dwarf pea. All the plants of F1 were found to be tall. This is due to:
If the heterozygous tall plant is crossed with a homozygous dwarf plant, then the percentage of progeny having dwarf character is ______
Some of the dominant traits studied by Mendel were
Select the group of CORRECT statements.
I. If phenotype of offsprings shows only the dominant trait then the parent plants are heterozygous.
II. A true breeding line shows stable trait inheritance and expression for several generations.
III. In mendelian experiment material, contrasting characters can be easily recognized.
IV. When a single gene controls two (or more) different traits, it is called polygene.
V. When interactions occurs between the alleles of different genes present on the same or different chromosome it is called intragenic interaction.
Which one of the following can be explained on the basis of Mendel’s Law of Dominance?
- Out of one pair of factors one is dominant and the other is recessive.
- Alleles do not show any expression and both the characters appear as such in F2 generation.
- Factors occur in pairs in normal diploid plants.
- The discrete unit controlling a particular character is called factor.
- The expression of only one of the parental characters is found in a monohybrid cross.
Choose the correct answer from the options given below:
