Yeast lacks a membrane-bound nucleus. The onion skin cell has one
Penumbra,<span> the Moon's faint outer shadow. Partial solar eclipses are visible from within the penumbral shadow.</span> And Umbra,<span> the Moon's dark inner shadow.<span> Total solar eclipses are visible from within the umbral shadow</span></span>
Metaphase I: The tetrads of chromosomes are lined up on the equator of the cell with the spindle apparatus having already been completely formed. It is during prophase I and metaphase I where genetic recombination occurs.
