What is a dominant allele GCSE biology?

Alleles may be either dominant or recessive: A dominant allele is always expressed, even if one copy is present. Dominant alleles are represented by a capital letter, for example, A. The allele for brown eyes is dominant. You only need one copy of this allele to have brown eyes.

What is a dominant allele in biology?

Definitions of dominant allele. an allele that produces the same phenotype whether its paired allele is identical or different. synonyms: dominant.

What is a recessive allele GCSE?

A recessive allele is only expressed if the individual has two copies of it and does not have the dominant allele of that gene. For example, the allele for blue eyes is recessive. You need two copies of this allele to have blue eyes.

What is a dominant allele example?

Dominant alleles show their effect even if the individual only has one copy of the allele (also known as being heterozygous?). For example, the allele for brown eyes is dominant, therefore you only need one copy of the ‘brown eye’ allele to have brown eyes (although, with two copies you will still have brown eyes).

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What is a dominant allele and how is it represented?

A dominant allele is denoted by a capital letter (A versus a). Since each parent provides one allele, the possible combinations are: AA, Aa, and aa. Offspring whose genotype is either AA or Aa will have the dominant trait expressed phenotypically, while aa individuals express the recessive trait.

What is a dominant allele Class 10?

– Dominant refers to the relationship between two versions of a gene. If the alleles (two versions of each gene) of a gene are different, one allele will be expressed as Dominant gene while the other allele effect is called recessive. … For example- Baldness, Curly hair is dominant over straight hair etc.

What is a dominant allele and recessive allele?

Dominant refers to the relationship between two versions of a gene. Individuals receive two versions of each gene, known as alleles, from each parent. If the alleles of a gene are different, one allele will be expressed; it is the dominant gene. The effect of the other allele, called recessive, is masked.

What is heterozygous GCSE biology?

Heterozygous alleles are both different for the same characteristic, for example Aa. Inheriting a brown eyed gene from one parent and a blue eyed gene from the other is called heterozygous.

What is a recessive allele in biology?

Recessive refers to a type of allele which will not be manifested in an individual unless both of the individual’s copies of that gene have that particular genotype.

How are dominant and recessive genes expressed in the phenotype?

A dominant allele produces a dominant phenotype in individuals who have one copy of the allele, which can come from just one parent. For a recessive allele to produce a recessive phenotype, the individual must have two copies, one from each parent.

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What is meant by dominant and recessive genes give one example of each?

The gene which decides the appearance of an organism even in the presence of an alternative gene is known as dominant gene. … For example, in pea plants, the dominant gene for tallness is T and the recessive gene for dwarfism is t.

What is an example of a dominant?

The definition of dominant is a person who is in a position of power or who is exhibiting powerful or controlling tendencies. An example of dominant is a strong and powerful CEO. … An example of a dominant gene is the brown-eyed gene, compared to the blue-eyed gene which is recessive.

Why are dominant alleles dominant?

Some proteins are dominant — they win out over their fellow proteins, just like dominant athletes win against their competitors. The simplest situation of dominant and recessive alleles is if one allele makes a broken protein. When this happens, the working protein is usually dominant.