<span>The correct answer for the question is Non-disjunction. Non-disjunction occurs in cell division when chromosomes do not divide properly. It can occur during mitosis, meiosis I and meiosis II. In mitosis it occurs when sister chromatids fails to separate in Anaphase. The result is that one cell receives both chromatids, while the other receives neither. Each daughter cell then has an abnormal number of chromosomes when mitosis is complete; one cell has an extra chromosome, while the other is missing one. In anaphase of meiosis I, it happens when a pair of homologous chromosomes does not separate. In meiosis II, it happens when a pair of sister chromatids fails to separate properly during anaphase of meiosis II, one daughter cell will have an extra chromosome and one daughter cell will be missing a chromosome.</span>
The right answer is The cells are damaged.
Take the example of skin cells.
The skin consists of two tissues:
* the outermost, the epidermis, resting on a vascularized connective tissue,
* the dermis.
In the epidermis, which includes several layers of cells, the outer layer is formed of dead cells that are desquamating and are constantly being replaced from proliferating basal cell cells. So, in normal conditions, the epidermis is in constant renewal.
On the other hand, when accidentally, the upper parts of the epidermis are damaged, for example, a slight abrasion or of a burn, the destroyed portion is regenerated (replaced) thanks to an accelerated proliferation of basal epidermal cells .
When Linnaeus developed his system of classification, there were only two kingdoms, Plants and Animals. But the use of the microscope led to the discovery of new organisms and the identification of differences in cells. A two-kingdom system was no longer useful. Today the system of classification includes six kingdoms.
Answer:
True, planets are round because of gravity
