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 .
Common characteristics of modern bears include large bodies with stocky legs, long snouts, small rounded ears, shaggy hair, plantigrade paws with five nonretractile claws, and short tails.
Some of these can easily be eliminated by knowing that both nitrogen 14 and nitrogen 15 are isotopes ( same element, with the same amount of protons, but with different numbers of neutrons) of nitrogen. So if the only difference between nitrogen 14, 15 , and regular nitrogen is the amount of neutrons...how many protons and electrons should both nitrogen 14 and 15 have? After thinking, you should be able to eliminate A, B,and C.
Because though there is a lot of available water, an ever shrinking 3% is freshwater, which comes from groundwater and streams. The ocean is salinated and in order for it to be fit to be used by humans for domestic needs or for drinking, it needs to undergo a huge desalination process which costs lots of money and time.
Autotrophs They make up the first level of every food chain. Autotrophs are usually plants or one-celled organisms. Nearly all autotrophs use a process called photosynthesis to create “food” (a nutrient called glucose) from sunlight, carbon dioxide, and water. so the answer is Autotrophs