Individual chromosomes are more difficult to see during interphase because they are not tightly coiled and condensed. During mitosis they are tightly coiled, making them easier to see. ... In anaphase I of mitosis, sister chromatids separate.
In the interphase, they are really thin, just one strand which is only a few atoms wide (very challenging for an optical microscope and not too easy for the electronic one)
I think that the best answer is first one: a) Trace the path that the sound waves travel as they enter the ear and proceed to the receptor cells for hearing, making sure to explain the process of transduction.
The research shows that for the cortex to evolve to be large, primates need a longer pregnancy, whereas a longer childhood is needed for a larger cerebellum to evolve. This means it is critical for infants to have the right environment to develop crucial skills.