Answer:
It is usually associated with physical growth delays, mild to moderate intellectual disability, and characteristic facial features. The average IQ of a young adult with Down syndrome is 50, equivalent to the mental ability of an eight- or nine-year-old child, but this can vary widely.
Symptoms: Delayed physical growth, characteristic facial features, mild to moderate i...
Other names: Down's syndrome, Down's, trisomy 21
Causes: Third copy of chromosome 21
Risk factors: Older age of mother, prior affected child
Explanation:
Hope it helps
FOLLOW MY ACCOUNT PLS PLS
Oxygen is transferred to the hemoglobin (red) cells in the blood, by close contact
through the thin tissue in the walls of the lungs. From there, it's carried throughout
the body by the circulation of the blood.