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Genes and Alleles

 
11.3 Genes and Alleles
 
Definition of Locus
A specific location of a gene in a chromosome.
 
Locus, Gene and Allele on A Pair of Homologous Chromosomes
  • Each chromosome carries many genes.
  • In human, the number of genes that code for proteins in a set of haploid chromosome is estimated to be 25 000.
  • Allele which represents a gene is located at the same locus as the gene.
  • The diagram below shows shows five genes with their respective alleles on specific loci of a pair of homologous chromosome.

This image shows a pair of homologous chromosomes. Key features include: - **Alleles**: Represented by letters (A, a, C, c, F, f, M, m) on the chromosomes. - **Centromere**: The central part where the chromosomes are connected. - **Homozygous dominant (FF)**: Same alleles on both chromosomes. - **Homozygous recessive (jj)**: Same alleles on both chromosomes. - **Heterozygous (Mm)**: Different alleles on each chromosome. - **Loci**: Specific locations on the chromosomes where genes are found. The image illustrates the genetic composition and variation within the homologous chromosomes.
 

 

 

 

 

The views expressed in the notes here are those of the contributor and don’t necessarily represent the views of Pandai.

Genes and Alleles

 
11.3 Genes and Alleles
 
Definition of Locus
A specific location of a gene in a chromosome.
 
Locus, Gene and Allele on A Pair of Homologous Chromosomes
  • Each chromosome carries many genes.
  • In human, the number of genes that code for proteins in a set of haploid chromosome is estimated to be 25 000.
  • Allele which represents a gene is located at the same locus as the gene.
  • The diagram below shows shows five genes with their respective alleles on specific loci of a pair of homologous chromosome.

This image shows a pair of homologous chromosomes. Key features include: - **Alleles**: Represented by letters (A, a, C, c, F, f, M, m) on the chromosomes. - **Centromere**: The central part where the chromosomes are connected. - **Homozygous dominant (FF)**: Same alleles on both chromosomes. - **Homozygous recessive (jj)**: Same alleles on both chromosomes. - **Heterozygous (Mm)**: Different alleles on each chromosome. - **Loci**: Specific locations on the chromosomes where genes are found. The image illustrates the genetic composition and variation within the homologous chromosomes.
 

 

 

 

 

The views expressed in the notes here are those of the contributor and don’t necessarily represent the views of Pandai.
Chapter : Inheritance
Topic : Gene and Allele
Form 5 Biology
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