Which of the following defines Down syndrome quizlet?

Which of the following defines Down syndrome?

Down syndrome is a condition in which a person has an extra chromosome. Chromosomes are small “packages” of genes in the body. They determine how a baby’s body forms and functions as it grows during pregnancy and after birth. Typically, a baby is born with 46 chromosomes.

Which of the following are characteristics of Down syndrome quizlet?

Characteristics

  • eyes that slant upward, have oblique fissures, have epicanthic skin folds on the inner corner, and have white spots on the iris.
  • low muscle tone.
  • small stature and a short neck.
  • a flat nasal bridge.
  • single, deep creases across the center of the palms.
  • a protruding tongue.

What is the most common cause of Down syndrome quizlet?

About 95 percent of the time, Down syndrome is caused by trisomy 21 — the person has three copies of chromosome 21, instead of the usual two copies, in all cells. This is caused by abnormal cell division during the development of the sperm cell or the egg cell.

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Which of the following is a physical manifestation of Down syndrome quizlet?

Common physical signs of Down syndrome include1,2: Decreased or poor muscle tone. Short neck, with excess skin at the back of the neck. Flattened facial profile and nose.

How is a syndrome defined?

A syndrome is a recognizable complex of symptoms and physical findings which indicate a specific condition for which a direct cause is not necessarily understood.

What is the scientific definition of Down syndrome?

A genetic condition caused by having an extra chromosome 21 in some or all of the body’s cells. Down syndrome is marked by growth, developmental, and learning delays that vary from mild to severe.

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.

Which of the following indicates Turner syndrome?

Signs of Turner syndrome at birth or during infancy may include: Wide or weblike neck. Low-set ears. Broad chest with widely spaced nipples.

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.

What are the 3 types of Down syndrome?

There are three types of Down syndrome:

  • Trisomy 21. This is by far the most common type, where every cell in the body has three copies of chromosome 21 instead of two.
  • Translocation Down syndrome. In this type, each cell has part of an extra chromosome 21, or an entirely extra one. …
  • Mosaic Down syndrome.
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What is the most common cause of Down syndrome quizlet maternal nondisjunction?

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).