Ventilation systems are needed in a <span>multicellular organism to actually obtain oxygen and give out carbon dioxide. Without this ventilation system, it would be very difficult for multicellular organisms to survive. It has been also observed that surface diffusion is not enough for a multicellular organism to breath.</span>
Answer: B
Explanation: So air, like most other substances, expands when heated and contracts when cooled. Radiation cooling occurs when air near the ground is cooled by the Earth's surface losing heat by radiation.
I think it might be the first one: hiv infections. (hope this helps!)
Answer:
Hi there, the answer is energy
Explanation:
Carbon dioxide, oxygen, and water are all products of cellular respiration in fact carbon dioxide and oxygen are extremely important for ATP. If you are talking about aerobic respiration oxygen is the main product for it because it reacts to glucose. The only thing that isnt part of the product of cellular respiration is energy. After ATP is created for the plants it makes its own energy afterward.
Hope this helped :)
DNA is coiled into proteins,,,,which makes up ur DNA (about 6,400,000,000 basepairs (DNA building blocks) that make up your DNA) basically...and...The way DNA is packaged into chromatin is a factor in how protein production is controlled. so in your nucleus....AGAIN....DNA IS KEPT OR COILED AROUND PROTEIN YET KEPT IN UR NUCLEUS... :)
... i hope this helps somewhat..
