What causes the amount of carbon dioxide in the air to increase?

When the oxygen produced by photosynthetic plants in the water dissolves in the water, which of these is being formed?

Nucleus has two lobes; contains granules of lysosomal enzymes; functions in attacking parasitic worms and plays complex roles in inflammatory diseases like allergies and asthma. what blood cells are described?

Which is an example of a vestigial structure? a: paw of a lionb: wing of a birdc: appendix of a humand: tail of a cat(i think it's a but i'm not sure)