Cell maintain homeostasis through diffusion in isotonic solution. Isotonic means that the concentrations are the same on either side of the membrane, maintaining homeostasis.
Answer:
47
Explanation:
We all know that gametes like egg cell and sperm have haploid set of chromosomes but here as per this question she has produced 2 copies of chromosome 21. For the sake of maintaining haploidy, she was supposed to have only a single copy of chromosome 21 as a result of which her egg cell was supposed to have 23 chromosomes not 24.
But, this is a case of non dis-junction. Also, in a normal sperm there are no such copies of any chromosome i.e. there is a haploid set of chromosomes. It means that sperm must be having only 23 chromosomes. So we can easily infer that when the egg cell and sperm will fuse, the zygote will have 47 chromosomes (24 from egg cell and 23 from sperm).
Answer:

Explanation:
Waves affect the ocean by creating disturbances that move energy through the water.
As the wind blows on the surface of the ocean, waves are created that transmit energy through the water from a starting point to an end point.
Answer: It would unbalance the ecosystem.
Due to the fact that if some species die off, the other species that rely on those species for food or protection would loose that food/ protection which may lead to their extinction and their extinction would lead to another extinction and so on.