A eukaryotic cell is classified this way if it B. contains a nucleus. In biology the definition of eukaryotic is "having a true nucleus" which is how to depict a prokaryotic cell from a eukaryotic cell.
B cytoplasm passes light threw the eye
The industrial revolution damaged our ecosystem
Well, when chromosomes cross over during prophase 1 of meiosis, the homologous pair of chromosomes exchange segments of DNA which happen to be the genes. So the significance of crossing-over during prophase 1 is that it adds genetic variation to sexually reproducing organisms.
For plants, it's photosynthesis.
