What do scientist use to determine the begining or end of a geologic time period? mass extinctions

diversification of life

index fossils

supercontinent formation and movement

index fossils

Explanation:

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i think it is c

Explanation:

The fossil forms that occur in the rocks, however, provide the chief means of establishing a geologic time scale, with the timing of the emergence and disappearance of widespread species from the fossil record being used to delineate the beginnings and endings of ages, epochs, periods, and other intervals. i am not trying to copy the other guy or girl

prophase: we can observe the chromosomes to coil up and condense. they become visible. nuclear membrane and envelope disintigrate.s

metaphase: chromosomes align at the center, the metaphase plate. spindle fibers attach to centromeres of the sister chromatids. they meet at kinetochores.

anaphase: sister chromatids are pulled towards each opposing centromere, set on different poles.

telophase: chromosomes are now clustered up only on either sides of the cell. nuclear membranes reform, and a new cell wall forms along the cell plate. this will lead to cytokinesis, the process that divides the cell membrane and forms the cell wall.

eukarya because is is like alche and b is bacteria and d is animals

explanation: