Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21.This additional genetic material alters the course of development and causes the characteristics associated with Down syndrome.People who inherit an unbalanced translocation involving chromosome 21 may have extra genetic material from chromosome 21, which causes Down syndrome
a genetic disorder that affects males. Klinefelter syndrome occurs when a boy is born with one or more extra X chromosomes. Most males have one Y and one X chromosome. Having extra X chromosomes can cause a male to have some physical traits unusual for males.Why does this occur?Males have an X and a Y sex chromosome (XY). Klinefelter syndrome can be caused by: One extra copy of the X chromosome in each cell (XXY), the most common cause.Klinefelter syndrome and its variants are not inherited; these chromosomal changes usually occur as random events during the formation of reproductive cells (eggs and sperm) in a parent. An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes.This syndrome occurs to males only.
Turner syndrome is a chromosomal condition that affects development in females. The most common feature of Turner syndrome is short stature, which becomes evident by about age 5.In an affected individual, it occurs as a random event during cell division in early fetal development. As a result, some of an affected person's cells have the usual two sex chromosomes, and other cells have only one copy of the X chromosome males and females...
is an abnormal condition characterized by the inability to clearly distinguish different colors of the spectrum. The difficulties can range from mild to severe. ... Rather, they tend to see colors in a limited range of hues; a rare few may not see colors at all.when the red and blue cones are simulated in a certain way you will see the colour purple. The exact physical causes of colour blindness are still being researched but it is believed that colour blindness is usually caused by faulty cones but sometimes by a fault in the pathway from the cone to the brain.