What condition is the result of trisomy 21 quizlet?

What condition is the result of trisomy 21?

Trisomy 21: About 95% of people with Down syndrome have Trisomy 21. With this type of Down syndrome, each cell in the body has 3 separate copies of chromosome 21 instead of the usual 2 copies. Translocation Down syndrome: This type accounts for a small percentage of people with Down syndrome (about 3%).

What is the cause of Down syndrome quizlet psychology?

An error in cell division called nondisjunction causes trisomy 21. This error leaves a sperm or egg cell with an extra copy of chromosome 21 before or at conception. This variant accounts for 95 percent of Down syndrome cases.

What is trisomy 21 an example of?

Down syndrome is a genetic disorder. It is also called trisomy 21. It includes certain birth defects, learning problems, and facial features. A child with Down syndrome also may have heart defects and problems with vision and hearing.

Which is a trisomic condition?

A trisomy is a chromosomal condition characterised by an additional chromosome. A person with a trisomy has 47 chromosomes instead of 46. Down syndrome, Edward syndrome and Patau syndrome are the most common forms of trisomy.

What causes Down syndrome quizlet?

The syndrome is caused by an extra copy of Chromosome 21, and in today’s Nature paper, researchers at the University of Massachusetts Medical School describe a way to “silence” that extra chromosome, meaning it’s still there but its genes don’t get “turned on,” they don’t function and cause problems.

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What is the most common cause of Down syndrome maternal nondisjunction?

Nondisjunction of chromosome 21 is the leading cause of Down syndrome. Two risk factors for maternal nondisjunction of chromosome 21 are increased maternal age and altered recombination.

Which process could cause trisomy 21 quizlet?

Down syndrome is caused by a random error in cell division that results in the presence of an extra copy of chromosome 21. The type of error is called nondisjunction (pronounced non-dis-JUHNGK-shuhn).