Answer:
B. photosynthesis and respiration keep the levels of oxygen and carbon dioxide fairly constant in the atmosphere.
Explanation:
We need cells for every day function. This includes significant processes like growth and development or protection from disease
Prokaryotic cells are smaller than eukaryotic cells and are simple while eukaryotic cells have nuclei prokaryotic cells don't
Answer: Higher.
Explanation:
It the ozone layer disappeared, life on the earth would be exposed to higher concentration of ultraviolet rays.
These rays are very harmful for the organism present on the earth. Exposure to the higher concentration of ultraviolet rays increases the chances of cancer in the organism.
higher exposure to UV rays can lead to mutation in the cells of the body which can in turn lead to many harmful diseases.
Answer: artery
Explanation:
The artery is the blood vessel that carry oxygenated (oxygen-rich) blood away from the heart while the vein carry deoxygenated(oxygen-poor) blood from the body to the heart.
Hence, all arteries carry oxygenated blood except pulmonary artery while all veins carry deoxygenated blood except pulmonary vein.
