8 Questions
What is the primary function of a gene?
To contain the information to express a particular trait
What is the result of a modified allele producing a non-functional enzyme or no enzyme?
The phenotype is dependent on the unmodified allele
Why do some alleles become recessive?
Because they are modified to produce a non-functional enzyme
What is the relationship between the two alleles in a heterozygote?
They may be identical or different
What is the role of the dominant allele?
It represents the original phenotype
What happens when a modified allele is equivalent to the unmodified allele?
The phenotype is not affected
Why is the unmodified allele considered dominant?
Because it represents the original phenotype
What is the result of a diploid organism having two copies of a gene?
The two alleles may be identical or different
Study Notes
Understanding Dominance
- A gene contains the information to express a particular trait, and in a diploid organism, there are two copies of each gene, known as alleles.
- These two alleles may not always be identical, as in a heterozygote, where one allele may be different due to changes that modify the information it contains.
- An allele can be modified to produce a normal or less efficient enzyme, a non-functional enzyme, or no enzyme at all.
- If the modified allele produces a normal or less efficient enzyme, it is equivalent to the unmodified allele and produces the same phenotype.
- However, if the modified allele produces a non-functional enzyme or no enzyme, the phenotype may be affected, and the trait will only be dependent on the functioning of the unmodified allele.
Dominant and Recessive Alleles
- The unmodified allele, which represents the original phenotype, is the dominant allele.
- The modified allele, which produces a non-functional enzyme or no enzyme, is generally the recessive allele.
- The recessive trait is seen due to the non-functional enzyme or lack of enzyme production.
Learn about the concept of dominance, how alleles interact, and what determines their dominant or recessive behavior. Understand the role of genes in expressing traits and how heterozygotes affect genetic expression.
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