Crossing over happens in Meiosis 1 only. In Prophase 1 a cells chromatin (chromatin = chromosomes that have not condensed yet) condense and pair up forming homologous chromosomes (paired = XX (2 chromosomes together)). When this happens segments/ alleles of the chromosomes pairing up swap over. This creates genetic diversity as each chromosome is different, it has parts from its pair. This leaves every chromosome unique and individual.
I hope this helps, sorry some of the vocab is rather technical. By the way I would suggest watching the
'Crash Course: Meiosis' on YouTube, this really helped me when I was learning this topic. :D
The glow stick that was in the cup of hot water will be brighter once it is bent. The production of more light is evidence that the chemical reaction in the glow stick is happening faster. The reaction happens faster, because increasing the temperature increases the rate of a chemical reaction.
The sister chromatids are then pulled apart by the mitotic spindle which pulls one chromatid to one pole and the other chromatid to the opposite pole.
The chromosomes line up neatly end-to-end along the centre (equator) of the cell.
The centrioles are now at opposite poles of the cell with the mitotic spindle fibres extending from them.
The mitotic spindle fibres attach to each of the sister chromatids.
The DNA in the cell is copied in preparation for cell division, this results in two identical full sets of chromosomes?.
Outside of the nucleus? are two centrosomes, each containing a pair of centrioles, these structures are critical for the process of cell division.
I. Facilitated diffusion is your answer.
Active transport <span>is the movement of molecules across a cell membrane into a region of higher concentration, this process requires energy. Both osmosis and diffusion are passive transportations which means that they don't require energy.
Hope this helps!
</span>
