Paired homologous chromosomes are attached to each other at the juncture called the centromere.
Are chromosomes separate strands of DNA?
Each chromosome is a pair of distinct, separate DNA molecules. A chromosome of an eukaryotic cell nucleus is a (long) helix of two linear molecules and so has two ends, which are called telomeres.
How are chromosomes paired together?
Chromosome pairing refers to the lengthwise alignment of homologous chromosomes at the prophase stage of meiosis. … The responsible cell division is meiosis and the mechanism is pairing/synapsis and subsequent separation of homologous chromosomes.
What are the 24 chromosomes?
The autosomes are normally present in pairs. The sperm contributes one sex chromosome (X or Y) and 22 autosomes . The egg contributes one sex chromosome (X only) and 22 autosomes . Sometimes microarray is referred to as 24-chromosome microarray : 22 chromosomes, and X and Y are counted as one each, for a total of 24.
How many DNA is in a chromosome?
One chromosome has 2 strands of DNA in a double helix. But the 2 DNA strands in chromosomes are very, very long. One strand of DNA can be very short – much shorter than even a small chromosome. Strands of DNA are made by joining together the 4 DNA bases in strings.
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 features are useful in pairing chromosomes?
The two chromosomes in a homologous pair are very similar to one another and have the same size and shape. Most importantly, they carry the same type of genetic information: that is, they have the same genes in the same locations. However, they don’t necessarily have the same versions of genes.