Answer: A tsunami is a giant wave (or series of waves) created by an undersea earthquake, volcanic eruption or landslide. Tsunamis are often called tidal waves, but this is not an accurate description because tides have little effect on giant tsunami waves.
Xyy redirects here. For the CIE XyY colour model, see XyY. XYY syndrome is a genetic condition in which a human male has an extra male (Y) chromosome, giving a total of 47 chromosomes instead of the more usual 46. This produces a 47,XYY karyotype, which occurs every 1 in 1,000 male births.or the CIE XyY colour model, see XyY. XYY syndrome is a genetic condition in which a human male has an extra male (Y) chromosome, giving a total of 47 chromosomes instead of the more usual 46. This produces a 47,XYY karyotype, which occurs every 1 in 1,000 male births.
Babies are normally born with 46 chromosomes; 22 pairs are identical in boys and girls, but the remaining pair consists of two X chromosomes in girls, and an X and a Y chromosome in boys. Occasionally, a child is born with 47; if the extra chromosome is a Y chromosome a boy is born with XYY syndrome. This has nothing to do with the parental age, health or ethnicity. It's not inherited, it's an accident at conception. XYY babies are born within the normal ranges for height and weight, but between the ages of 12 to 14 they grow about four inches a year. The average height for a British man is 5ft 10in, while for an XYY man it is 6ft 3in. They may be slower to learn to speak, although most catch up with the help of speech therapy.