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.
Answer:
it contains one original strand and one newly synthesised strand.
Because that's the starting tempture to rising. for example if your body temperature starts naturally at 80°, as the weather changes your tempture it increases or decreases as it goes.
Answer:
By domesticting plants and animals, humans were able to modify the plants and animals to suit their needs.
Explanation:
Early humans didn't know that domesticting and manipulating plants and animals is explained through biology, nor did they have the term "biology", however, domestication certainly contributed to people becoming curious as to how and why these processes worked.
A microscope is to see smaller things that you can’t see and it is a really good tool.
