Down syndrome is a genetic disorder caused when abnormal cell division results in an extra full or partial copy of chromosome 21
Down syndrome is a genetic disorder caused when abnormal cell division results in an extra full or partial copy of chromosome 21
Down syndrome is usually caused by an error in cell division called nondisjunction which results in an embryo with three copies of chromosome 21 instead of the usual two
Prior to or at conception, a pair of 21st chromosomes in either the sperm or the egg fails to separates
With development in embryo the extra chromosome is replicated in every cell of the body;this type of Down syndrome which accounts for 95% of cases is called trisomy 21
Maternal age is the only factor that has been linked to an increased chance of having a baby with Down syndrome resulting from nondisjunction;here environmental agents such as drugs, chemicals, and radiation act as mutagens which induce mutation in the fetus
Down syndrome; is a condition in which there is an extra copy of a chromosome, total chromosomes are 47 (46+1). The patient of Down syndrome contain an extra copy of 21 th chromosome. Chromosome determine how a baby's body forms during pregnancy and how the baby's body functions as it grows in the womb and after birth. Typically, a baby is born with 46 chromosomes, but in case of down syndrome, there is an extra copy of 21 number chromosome, which cause greater risk of abnormality in fetus of aging oocyte.
The following are the two considerations demonstrating that there would be less biodiversity than the tropical areas in the Mediterranean climate as well as polar areas.
The first reason is all tropical areas experience drastic temperature variation.
The second reason is early in the earth's history, the northern latitudes are inhabited.
