When the identical alleles are present on two chromosomes for a particular trait, the chromosomes are said to be homozygous.
Further Explanation:
The extent to which the genetic sequence of both the copies of a gene is the same is called zygosity. It can also be considered as the percentage of similarity the alleles have in an organism. The eukaryotes are mostly diploid in nature which implies that they contain chromosomes in a matching pair. In a diploid organism, the homologous chromosomes are present on the same loci but the two chromosomes can differ in the sequences at the loci. When both the alleles are the same in a diploid organism, then the organism is said to be homozygous. On the other hand, if the alleles differ in the nucleotide sequence, they are called heterozygous.
Different individuals have different DNA sequences for the same gene. These differences in the sequences form different forms of the same gene called alleles. Some genes have just one allele as any deviation in the allelic sequence might be fatal, while some other genes have more than one allele. The frequency of these alleles varies among a population. Two alleles might have an equal distribution in the population or one allele might be very common, making the other allele rare. The alleles are inherited from each parent which pair up in the zygote. The zygosity describes whether the two alleles are the same or different in their DNA sequences.
When two chromosomes contain the same copies of the alleles, they are called homologous chromosomes and the organism is termed as homozygous. An individual can be homozygous-dominant or homozygous-recessive depending on whether it has dominant or recessive copies of the alleles. The homozygous-dominant individual will express the dominant phenotypic traits while the individual who is homozygous-recessive will have a recessive trait.
Learn More:
1. Learn more about meiosis brainly.com/question/1600165
2. Learn more about the process of molecular diffusion in a cell brainly.com/question/1600165
3. Learn more about human sperm and egg cell brainly.com/question/1626319
Answer Details:
Grade: High School
Chapter: Zygosity
Subject: Biology
Keywords:
zygosity, homozygous, heterozygous, homologous chromosomes, genes, allele, DNA, nucleotide sequence, dominant, recessive, trait.
