Someone do 4, 5 and 6 for me

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

Now it's your turn to investigate human impact around the world. grab your virtual lab coat and put on your environmental science hat. you will be taking a trip around the globe to explore three locations. at each location, you will investigate the cause and effect relationships of deforestation, desertification, and urbanization. you will also gather evidence of how these factors have impacted the environment over time

What are the formed elements (cell or parts of cell) in blood and what are their functions ?