Help with Honors Biology hw, please?

Question

1) Skeletal muscle cells are multi-nucleated, that is, each cell contains more than one nucleus. Explain how this could come about, given what you know about nuclear division and cytoplasmic division.

2) What phase of the cell cycle are most of your skin cells in right now? (prophase, metaphase, anaphase, telophase)

I already tried googling.

Thank you.

Answer 1

1. Telophase overlaps with beginning of cytoplasmic division. Spindle fibers vanish as quickly as they appeared and the chromosomes begin to unpack themselves, and become less and less visible to staining with dyes.

As the chromosomes diffuse out, exposing their DNA, new nuclear membranes begin to form around them, separating them from the cytoplasm of the cell and allowing the start of RNA synthesis (for interphase) once more. One or more nucleoli may now reappear.

These events overlap with the important division of the cytoplasm of the original cell, the distribution of its organelles and contents, and the physical separation of the original cell into two halves; cytokinesis.

2. anaphase

Answer 2

1) muscle cells fuse together leading to multinuceate cells. I am pretty sure that they don't just forego cytoplasmic division as hinted here.
2) not sure about this, but mitosis is a comparatively short process in comparison to the cell growth process in the interphase. So I would assume despite continuously new skin cells are formed, most of my skin cells are actually in the interphase (actually a noticable number of my skin cells are dead and are in no phase at all and don't have a nucleus any more). And cell division happens in just one of the 5 layers of the skin, the stratum germinativum (or stratum basale), so the majority of the skin cells are not in cell division.

Answer 3

Holy crap! That's honors? I'm in honors bio and we're still on photosynthesis and cell respiration. I'm so sorry...but I have no clue. I wish I could help.