I think that having an extra chromosome 21 is tolerable to the point that someone with this condition can survive to maturity because it does not replicate.
There should only be a pair of chromosome 21. In the event that there are 3 chromosome 21, the person that has this extra chromosome has Down syndrome. Changes in the number and structure of this chromosome may result to delayed development, intellectual disability, but not immediate death.
Type of species or breed effectively.
Draining the oceans would show features such as mid-ocean ridges. These features would look like an extensive mountain range running down the spine of the ocean floor. This region marks the area where two oceanic tectonic plates are being pushed apart. Closer to land or the continents would be a gentle shelf that gradually deepens as one moves away from the coastline. This relatively gentle plain would then make a steep drop off down to an extensive plain stretching towards ocean ridges. The ocean floor also supports lone mountain structures, canyons and chasms.
Answer:
In wells Scientist measure dissolved oxygen, or DO (pronounced dee-oh).
Answer:
the first one is plants
the second one is animals
the third one is plants
the fourth one is animals
