It is a genetic condition caused when an unusual cell division result in an extra full or even partial copy of chromosome 21.

The diminutive chromosome 21--the smallest of the human contingent, despite its number as next to last--is the fourth to be described. Its debut in mid-May attracted attention because 21 is a ...

Down syndrome is a genetic disorder caused by an extra chromosome 21, affecting brain and body development. It leads to ...

Chromosome 21 is the smallest human chromosome, and procedures for examining human chromosomes were still being developed during the first part of the century. Many early cytologists had ...

As illustrated in Figure 1, chromosome 21, which is the smallest human chromosome, shows the lowest Hoechst and chromomycin staining intensity. Chromosomes 1 and 2, which are the largest human ...

In particular, it explains that humans have one fewer chromosome pair in their cells than apes, due to a mutation found in chromosome number 2 that caused two chromosomes to fuse into one.

Human biological sex is determined by the sex chromosomes X and Y. In most cases, females possess two X chromosomes, while males have one X and one Y. However, there is some evidence that the Y ...

The nucleus of each human body cell contains 46 chromosomes. Each chromosome contains about 1000 genes. There is enough DNA in all the cells in a human body to stretch to the sun and back again ...

Human-accelerated regions (HARs) in chromosomes help human neurons grow multiple neurites. When HARs were added to artificial chimpanzee neurons, as seen on the right, they grew extra neurites, ...