Dna or protein can be used as a molecule clock that tells how long it has been since two species have diverged from a common ancestor

DNA or protein can be used as a ''molecular clock'' that tells how long it has been since two species have diverged from a common ancestor. The fossil record is usually derived from sedimentary rocks laid down millions of years ago.

answer; a male inherits only one allele of the x-linked gene controlling hair color;

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.