What happens during the light reaction of photosynthesis? Carbon dioxide molecules combine to make food.

Water molecules are split apart.

Air and soil create energy for a plant.

Carbon dioxide is combined with glucose.

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?