At the onset of the embryonic period, the appear(s). it will eventually become the neural tube. stem cells spinal cord primitive streak placenta

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.

the dark variety, as they are not visible on the dark tree barks

explanation:

the farther away the object is from the central star (the sun) it's gravitainal pull on the object is weaker when it is farther

explanation: