Nucleus, Mitochondria, and Lysosomes are found in a cell. Plastid is the odd one.
Corpus Callosum is a band of thick fibres which connects the hemispheres of the brain.
option 2 seems appropriate for me!
No idea about the scientific reasoning, but the leaves of the plant are where the most photosynthesizing has to happen. In order for the plant to get energy it has to absorb the most light. So it creates broad leaves. The reason they are green is because chloroplasts are green. I believe that the cells in the leaves have more chloroplasts so that they can catch more sunlight.<span />
Facilitated diffusion of substances crossing the cell (plasma) membrane takes place with the help of proteins such as channel proteins and carrier proteins.