AnswersDriveAllele: The alternative forms of a gene, like the "tall" and "short" versions of the gene for height in garden peas. Dominant: An allele that produces the visible or measurable trait in an organism and is expressed over recessive genes. Dominant alleles are represented by a capital letter ("T").
Consequently, what is an allele of a gene?
An allele is a variant form of a gene. Some genes have a variety of different forms, which are located at the same position, or genetic locus, on a chromosome. Humans are called diploid organisms because they have two alleles at each genetic locus, with one allele inherited from each parent.
What is an example of an allele?
The definition of alleles are pairs or series of genes on a chromosome that determine the hereditary characteristics. An example of an allele is the gene that determines hair color.
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What is an allele and how is it represented?
Allele: The alternative forms of a gene, like the "tall" and "short" versions of the gene for height in garden peas. Dominant: An allele that produces the visible or measurable trait in an organism and is expressed over recessive genes. Dominant alleles are represented by a capital letter ("T").
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What letter represents the dominant gene?
genotype = the genes of an organism; for one specific trait we use two letters to represent the genotype. A capital letter represents the dominant form of a gene (allele), and a lowercase letter is the abbreviation for the recessive form of the gene (allele).
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What are Mendel's factors called today and where are they found?
Mendel found that there are alternative forms of factors—now called genes—that account for variations in inherited characteristics. For example, the gene for flower color in pea plants exists in two forms, one for purple and the other for white. The alternative "forms" are now called alleles.
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Is a carrier homozygous or heterozygous?
Heterozygous means that an organism has two different alleles of a gene. For example, pea plants can have red flowers and either be homozygous dominant (red-red), or heterozygous (red-white). If they have white flowers, then they are homozygous recessive (white-white). Carriers are always heterozygous.
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What is a phenotypic ratio example?
For example, a test cross between two organisms with same genotype, Rr, for a heterozygous dominant trait will result in offspring with genotypes: RR, Rr, and rr. And in this example, the predicted genotypic ratio is 1:2:1. Compare: phenotypic ratio.
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How many alleles must be present in order for a particular trait to show up in the offspring?
Genes/Two alleles must be present in order for a trait to show up in the offspring. One must come from mom, and the other from Dad. When fertilization occurs, the new offspring will have 2 alleles for every _____.
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What factors besides alleles affect the phenotype?
Phenotype. Phenotype is the observable physical or biochemical characteristics of an individual organism, determined by both genetic make-up and environmental influences, for example, height, weight and skin colour.
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What is meant by heterozygous?
The genetics term heterozygous refers to a pair of genes where one is dominant and one is recessive — they're different. Like all words with the prefix hetero, this has to do with things that are different — specifically genes. If you inherited the same gene from both parents, it's homozygous — the same.
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How is a carrier different from a person who has a genetic disorder?
All the other chromosomes other than sex chromosomes. How is a carrier different than a person that has a genetic disorder? A carrier does not show symptoms of a disorder like a person with a genetic disorder would do. Males show phenotypes from both sexes; females have phenotypes similar to autosomal gene expression.
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How is a gene related to a trait?
Alleles are each of two or more alternative forms of a gene that are found at the same position in a chromosome. Traits on the other hand, are the characteristics that are defined by genes. So the combination of alleles for a gene is what manifests itself into a trait.
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What do you mean by phenotype?
The physical appearance of an organism as distinguished from its genetic makeup. The phenotype of an organism depends on which genes are dominant and on the interaction between genes and environment. Compare genotype.
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How can a recessive trait be expressed?
Only individuals with an aa genotype will express a recessive trait; therefore, offspring must receive one recessive allele from each parent to exhibit a recessive trait. One example of a recessive inherited trait is a smooth chin, as opposed to a dominant cleft chin.
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What is the dominant and recessive alleles?
The terms dominant and recessive describe the inheritance patterns of certain traits. For a recessive allele to produce a recessive phenotype, the individual must have two copies, one from each parent. An individual with one dominant and one recessive allele for a gene will have the dominant phenotype.
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What does the term homozygous mean?
Homozygous refers to having identical alleles for a single trait. An allele represents one particular form of a gene. Alleles can exist in different forms and diploid organisms typically have two alleles for a given trait. Homozygous alleles may be dominant or recessive.
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What is a TT genotype?
Sometimes the term "PURE" is used instead of homozygous. When the GENOTYPE is made up of one capital letter & one lowercase letter (ex: Tt) it's called HETEROZYGOUS ("hetero" means "other"). Just to confuse you, a heterozygous genotype can also be referred to as HYBRID.
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How are dominant and recessive alleles expressed?
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.
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What is the dominant allele?
n an allele that produces the same phenotype whether its paired allele is identical or different. Synonyms: dominant Type of: allele, allelomorph. (genetics) either of a pair (or series) of alternative forms of a gene that can occupy the same locus on a particular chromosome and that control the same character.
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What is the alternative form of a gene?
The alternative form of a gene is called allele. In a simple genetic trait there are two genes contributed by each parents (paternal and maternal). Thus, the alternative forms of the gene in the genotypes is termed as allele or alleles.
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What is an example of a genotype?
Genotype and phenotype are very similar-sounding words that are related, but actually mean different things. The genotype is the set of genes in our DNA which is responsible for a particular trait. The phenotype is the physical expression, or characteristics, of that trait.
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What is the phenotype of dimples?
Sally's genotype is "dd", so she is also considered homozygous. Susan's genotype is "Dd", so she is considered HETEROZYGOUS (has two different alleles for a specific gene). Although Susan has both the allele "D" to make dimples and the allele "d" in her genotype, her phenotype is the presence of dimples.