Explanation:
Nondisjunction: Failure of paired chromosomes to separate (to disjoin) during cell division, so that both chromosomes go to one daughter cell and none go to the other. Nondisjunction causes errors in chromosome number, such as trisomy 21 (Down syndrome) and monosomy X (Turner syndrome). It is also a common cause of early spontaneous abortions
Whatever you do do not click on that link
ANSWER:
After the volcanic eruption,lava cools down,vegetation reappears and microscopic plants grow,then the macroscopic plants and animals come at that place,then gradually the whole system builds and ecosystem recovers.
EXPLANATION:
Biodiversity means diverse population of plants and animals. After the volcanic eruption,both plants and animals donot exist because of high temperature and not suitable environment. With the passage of the time, the lava cools down and vegetation stars reappearing. First of all lichens and microscopic plants and after that macroscopic plants and animals come at that place.Thus suitable conditions reappear and gradually the whole ecosystem recovers.
Its called osmosis and it only happens with water. now I'm just adding words to be able to post this. its moving down the concentration gradient.