What is biological evolution?

The oxidizing agent our bodies use to obtain energy from food is oxygen (from the air). if you breathe 15 times a minute (at rest), taking in and exhaling 0.5 l of air with each breath, what volume of air do you breathe each day? air is 21% oxygen by volume. what volume of oxygen do you breathe each day?

Hummingbirds drink nectar from flowers, while robins eat plant seeds. what does this reduce?

Glucose is broken down in different ways, both in the presence and in the absence of oxygen. using the table for reference, what major products are formed in each reaction set?