An allele is dominant if it is expressed inA: Both homozygous and heterozygous statesB: second generationC: Heterozygous combinationD: Homozygous combinationCorrect answer is option 'A'. Can you explain this answer?

Question

Answer

If the allele expresses in both it's homozygous and heterozygous condition..it is dominant....whereas reccesive allele can be expressed only in homozygous condition

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An allele is dominant only if it gets expressed in  heterozygous combination.because  The homozygous combination is the condition in which both the alleles are similar, i.e. a gene has identical alleles on both the chromosomes( homologous chromosomes).

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Both.. homozygous and heterozygous state...

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Express in both homozygous and heterosygous

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Heterozygous combination

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An alternative form of a character in a pair, controlled by a single gene is called Allele. It is dominant either in a homozygous or heterozygous state.

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Wrong

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It should be heterozygous.....as recessive allele also expresses it's effect during homozygous condition..

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Introduction:
In genetics, alleles are different forms of a gene that can occupy the same position (locus) on a chromosome. Alleles can be either dominant or recessive, depending on their expression in an organism. The expression of an allele refers to its ability to produce a specific trait or phenotype.

Explanation:
The correct answer to the question is option 'A' - an allele is dominant if it is expressed in both homozygous and heterozygous states. Let's understand the concept in more detail:

1. Homozygous state:
- Homozygous refers to having two identical alleles for a particular gene.
- In the case of a dominant allele, if an organism has two copies of the dominant allele (AA), the dominant trait associated with that allele will be expressed.
- For example, in Mendelian genetics, the allele for brown eye color (B) is dominant over the allele for blue eye color (b). If an individual has two copies of the dominant brown allele (BB), they will have brown eyes.

2. Heterozygous state:
- Heterozygous refers to having two different alleles for a particular gene.
- In the case of a dominant allele, if an organism has one copy of the dominant allele and one copy of the recessive allele (Aa), the dominant trait associated with the dominant allele will still be expressed.
- Using the previous example, if an individual has one copy of the brown allele (B) and one copy of the blue allele (b) (Bb), they will have brown eyes because the dominant brown allele is expressed.

3. Dominant expression:
- Dominant alleles are expressed even in the presence of a recessive allele.
- This means that if an organism has at least one copy of the dominant allele, the trait associated with that allele will be expressed.
- Dominant alleles mask the expression of recessive alleles in heterozygous individuals.
- In the case of recessive alleles, they are only expressed when an organism has two copies of the recessive allele (aa).

Conclusion:
In summary, an allele is considered dominant if it is expressed in both homozygous and heterozygous states. This means that individuals with either two copies of the dominant allele or one copy of the dominant allele will show the trait associated with that allele.

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