Heterozygous is a term used in genetics to describe when two variations of a gene (known as alleles) are paired at the same location (locus) on a chromosome. By contrast, homozygous is when there are two copies of the same allele at the same locus.
What is an example of a heterozygous allele pair?
If the two versions are different, you have a heterozygous genotype for that gene. For example, being heterozygous for hair color could mean you have one allele for red hair and one allele for brown hair. The relationship between the two alleles affects which traits are expressed.
What alleles are called heterozygous?
Each pair of alleles represents the genotype of a specific gene. Genotypes are described as homozygous if there are two identical alleles at a particular locus and as heterozygous if the two alleles differ.
Are heterozygous for only one pair of alleles?
Mendel’s Law of Independent Assortment states the inheritance of one pair of factors ( genes ) is independent of the inheritance of the other pair. If the two alleles are identical, the individual is called homozygous for the trait; if the two alleles are different, the individual is called heterozygous.
What is heterozygous in simple words?
Heterozygous refers to having inherited different forms of a particular gene from each parent. A heterozygous genotype stands in contrast to a homozygous genotype, where an individual inherits identical forms of a particular gene from each parent.
When would a pair of alleles be heterozygous quizlet?
Heterozygous means that an organism has two different alleles of a gene. An organism can be homozygous dominant, if it carries two copies of the same dominant allele, or homozygous recessive, if it carries two copies of the same recessive allele. Heterozygous means that an organism has two different alleles of a gene.
What is the pair of alleles an organism possesses called?
genotype. a pair of alleles an organism possesses called. hybrid offspring.
What happens to the alleles of a gene pair?
Genes come in pairs (that is, are present in two copies in an organism). Genes come in different versions, now called alleles. When an organism has two different alleles of a gene, one (the dominant allele) will hide the presence of the other (the recessive allele) and determine appearance.
Why do alleles occur in pairs?
As chromosomes occur in pairs for each characteristic, there are two possible alleles. … The different versions of alleles occur as DNA base sequence varies. Such a combination of alleles for each characteristic is a genotype, which could be a combination of two of the available alleles.
What are homozygous and heterozygous alleles?
Homozygous: You inherit the same version of the gene from each parent, so you have two matching genes. Heterozygous: You inherit a different version of a gene from each parent.
What is dominant and recessive alleles?
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.
Why does an individual always have only two alleles for a given gene?
Since diploid organisms have two copies of each chromosome, they have two of each gene. Since genes come in more than one version, an organism can have two of the same alleles of a gene, or two different alleles. This is important because alleles can be dominant, recessive, or codominant to each other.
Is heterozygous a genotype or phenotype?
An organism with one dominant allele and one recessive allele is said to have a heterozygous genotype. … Of these three genotypes, only bb, the homozygous recessive genotype, will produce a phenotype of blue eyes.
What is meant by homozygote?
homozygote, an organism with identical pairs of genes (or alleles) for a specific trait. If both of the two gametes (sex cells) that fuse during fertilization carry the same form of the gene for a specific trait, the organism is said to be homozygous for that trait.
What is pairs of chromosomes encoding information for the same traits?
Homologous chromosomes are two pieces of DNA within a diploid organism which carry the same genes, one from each parental source. In simpler terms, both of your parents provide a complete genome. Each parent provides the same 23 chromosomes, which encode the same genes.