The “p arm” and “q arm” of the chromosome are attached to the centromeres. Notably, important genes are not present in the centromeric region of the chromosome. It provides an attachment point to complete the replication properly. Centromere:įirst of all, the centromere is not a center of the chromosome, remember that, based on the location of the centromere, chromosomes are categorized into different categories.Īctually, a constricted, narrow and somewhat rounded region of a chromosome holds chromatids known as the centromere.ĭuring the process of cell division, and when replication is in progress, the centromere plays an important function to align chromosomes properly to replicate. The graphical representation of the structure of chromosome- centromere, arms and telomeres.

The presence or absence of the X chromosome decides whether the developing embryo becomes female or male. The SRY- a sex-determining region of Y, responsible for maleness and helps in the development of male phenotypes although it is solely not decided the fate of embryo. Interestingly, a mechanism called X-chromosome inactivation helps to inactivate one X chromosome for regulating gene expression, especially in females. Hence XX in females and XY in the male are denoted as sex chromosomes. The 22 pairs of chromosomes are the same in all-male and females, however, one pair of sex chromosomes decide their gender.Ī pair of the X chromosome is present in females while a single X along with a short Y chromosome is present in males. All chromosomes are present in a pair thus a total of 46 chromosomes are present in 23 pairs called a diploid number of chromosomes.Īll the somatic cells have a diploid number of chromosomes while egg and sperm- germ cells have a haploid number of chromosomes.Īll the nuclear- DNA of a cell is arranged on these 23 pairs of chromosomes, however, some linear or circular DNA is also present in the cytoplasm. “A complex network of DNA and protein- coiled around each other and helps to fit DNA inside the nucleus is known as a chromosome.” Human chromosomes:Ĥ6 chromosomes are present in each human cell, except germ cells. “DNA of eukaryotes such as plants and animals is arranged as a tightly packed thread-like structure known as a chromosome.” The number of chromosomes in different organisms are Given below, Organism Number of chromosomes (2n) Human 46 Potato 48 RIce 24 Monkey 42 Mouse 40Īdders- tongue (Ophioglossum) has the highest number of chromosomes – 1260 while jack-jumper ant (Myrmecia pilosula) has the lowest number of chromosomes- 2. Unlike the prokaryotic DNA, the DNA of eukaryotes is arranged on chromosomes having centromere, telomere, p arm and q arm.Ī prokaryotic chromosome is either made up of DNA or RNA (RNA in the case of some viruses)- but not located in the nucleus.ĭifferent species have a different number of chromosomes based on their genome size. Later on in the year, 1883 Wilhem roux speculated chromosomes as a carrier of genetic information. In 1882, Wilhelm Hofmeister denoted the term as “chromosomes”. In 1842, Karl Wilhelm von Nageli, a swiss botanist discovered a structure which later known as chromosomes. In the present article, I will explain to you the structure and function of the chromosome along with other information related to it.Ĭhromosome= chroma (colour) + some (body) Ĭhromosomes are a complex network of protein and DNA helps DNA to organize during cell division and protects it. As we said above it is located on chromosomes, all the DNA of us is known as a genome- tailored with coding DNA non-coding DNAs.Ĭhromosomes are basic inheritance unit varies from species to species. It is a basic unit of inheritance and was discovered by Watson and Crick in 1953.

Let me give you a brief overview of nucleic acid,ĭNA- a type of nucleic acid is present in live-cell, in a membrane-bounded structure called a nucleus. We all know about DNA right! If not, read our previous article on DNA: DNA story: structure and function of DNA. “An essential element of life- chromosomes are located in the nucleus of a cell on which the entire genomic DNA of an organism is arranged.”īy coiling and supercoiling with each other DNA- deoxyribose nucleic acid forms threads of the chromosome.

Symbol for female chromosome