Answer:
I believe your answer should be B.) Materials were pulled together by gravity. I hope this helps you!
<span>Stem cells. There are two types of stem cells: adult stem cells - these are unspecialised cells that can develop into many (but not all) types of cells. Embryonic stem cells - these are unspecialised cells that can develop into any type of cell. And that's all! ;)
Hope this is useful !!!^_~!!!</span>
<span>The thing that might happen to the tree was it might get swept away by the current until it catches on something or disappears (dissolves). The tree will going to the flow of the river until it catches on something where it may disappears or dissolve.</span>
Answer:
When cells work together to perform a specific function, that group of cells is called a tissue. Cartilage is a type of connective tissue made from many cells. Other types of tissues in your body include your muscles and skin. Complex multicell organisms have many different types of tissues, all comprising two or more types of cells.
Answer: crossing over allows for genetic variation
Explanation:
crossing over is the exchange of genes between two chromosomes which ends up resulting in non-identical chromatids that comprise the genetic material of gametes (sperm and eggs).
Basically crossing over makes the chromatids that are held together by a centromere, no longer identical to eachother which creates genetic variation.