I’m not sure but I’m guessing the answer would be the first one !
Answer:
c.assembling parts of the virus
Answer:
Genetic variations that alter gene activity or protein function can introduce different traits in an organism. If a trait is advantageous and helps the individual survive and reproduce, the genetic variation is more likely to be passed to the next generation (a process known as natural selection
Explanation:
From mouth/nose, the air passes to the trachea (the wind pipe), there it enters (sequentially) the bronchi, bronchioles (small pipe-like structures), alveoli (widened empty sacs), the walls of which are in close contact with the blood vessels which contain the RBCs, which in turn contain the protein--hemoglobin, which binds to the oxygen present in the freshly inhaled air, and loses the carbondioide present DISSOLVED in the blood. This bound oxygen goes to the heart (of course along with the RBCs in the blood), from there to the smaller and smaller arteries, then to the capillaries, where again oxygen is lost to the surrounding tissue fluid, from where the cells collect oxygen by simple diffusion, and lose carbon dioxide, which gets dissolved in the water present in the blood.
From here the blood, with hemoglobin poorer in oxygen, and richer again in carbondioxide goes to the venules, and veins (capillaries continue as venules), which become successively larger to become superior and inferior vena cava and enter the right atrium, and then from there the blood again goes to the lungs and comes in contact with fresh air in the alveoli.
It is convenient to divide the photosynthetic process in plants into four stages, each occurring in a defined area of the chloroplast: (1) absorption of light, (2) electron transport leading to the reduction of NADP+ to NADPH, (3) generation of ATP, and (4) conversion of CO2 into carbohydrates (carbon fixation).
