A homologous pair consists of one paternal and one maternal chromosome. In humans, there are a total of 46 chromosomes in the nucleus of a somatic cell. Half of them (22 autosomes + X or Y chromosome) are inherited from the father and the other half (22 autosomes + X chromosome), from the mother.
What is homologous chromosome?
Homologous chromosomes: A pair of chromosomes that contain the same gene sequences, each derived from one parent.
Where are the Homologous chromosomes?
During metaphase I, the homologous chromosomes are arranged in the center of the cell facing opposite poles. Random orientation of the homologous pairs occurs at the equator. This is important in determining the genes carried by a gamete. Each gamete will only receive one of the two homologous chromosomes.
What is homologous chromosome Class 12?
Homologous chromosomes are defined as two pieces of DNA within an organism who is a diploid (2n) which carry the same genes one from each parent i.e. one from a father and one from the mother. … Each parent contributes 23 chromosomes which encode the same genes.
What do you mean by homologous?
1a : having the same relative position, value, or structure: such as. (1) biology : exhibiting biological homology. (2) biology : having the same or allelic genes with genetic loci usually arranged in the same order homologous chromosomes.
Are alkanes a homologous family?
The alkanes are a homologous series of hydrocarbons . This means that they have similar chemical properties to each other and they have trends in physical properties. For example, as the chain length increases, their boiling point increases.
Why are alkanes unreactive?
In comparison to alkenes and alkynes, alkanes are relatively unreactive due to the absence of a weaker pi bond in their carbon skeletons.
Do all cells have homologous chromosomes?
All cells have homologous chromosomes except for the reproductive cells of higher organisms. Cells with homologous chromosomes are diploid. Reproductive cells, called gametes, are different. They contain only half the full number of chromosomes—one chromosome from each pair.
What is the main difference between Chromatin and chromosomes?
Chromatin is a complex formed by histones packaging the DNA double helix. Chromosomes are structures of proteins and nucleic acids found in the living cells and carry genetic material. Chromatin is composed of nucleosomes. Chromosomes are composed of condensed chromatin fibers.
What is the same in all parts of homologous chromosomes?
Homologous chromosomes are similiar but not identical. Each carries the same genes in the same order, but the alleles for each trait may not be the same. … The maternal and paternal chromosomes in a homologous pair have the same genes at the same loci, but possibly different alleles.