What is a group of cells that are similar in structure working together to perform a similar function

In attempt to solve the working problems created by the industrial revolution, the united states and many countries in europe considered and/or adopted

Elephants in the savanna regions of africa dig holes in dried up river beds to reach water lying just below the surface. these holes provide drinking water for other animals as well. so, without the elephants, many animals might otherwise die from lack of water during the dry season. the location in which the elephants live is an example of a/n and the role they play in creating water holes is an example of a a) ecosystem; habitat b) community; niche c) habitat; niche d) niche; habitat

Which is a function performed by stem cells in the skin a. replacing lost skin cells b. making cells for the intestines c. growing new organs d. differentiating into brain cells plz apex