Who knows how to label these

Where do homologous chromosomes exchange genetic material through crossing over?               a.  chlorophyll    b.  centrosomes    c.  centromeres    d.  chiasma

Biomass can be used to generate electricity. biomass relies heavily on agricultural crops. plants release carbon dioxide and water in combustion. plants use photosynthesis to originally generate the energy that is needed. the chemical energy of these plants all started with what energy source?

The nervous system interacts with the endocrine system by a. using hormones as connections b. sending nerve impulses directly to glands c. using neuroendocrine cells as connections d. sending neurotransmitters directly to neurons