Someone, please help!

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

The chromosomal structure that limits the number of cell divisions of a cell is the the chromosomal structure that limits the number of cell divisions of a cell is the kinetochore telomere histones centromere

Monomers are the building blocks of larger molecules, called polymers. for example, proteins are composed of chains of amino acids that are linked together. cellulose is a polymer that makes up plant cell walls. cellulose is made from a chain of c6h10o5 molecules. which monomers are most likely used to produce cellulose? why?