Which of the following statements is true about gas diffusion across respiratory membranes?

The picture shows a fishing technique called trawling. how might trawling affect marine biodiversity

Penicillin is hydrolyzed and thereby rendered inactive by penicillinase (also known as β-lactamase), an enzyme present in some resistant bacteria. the mass of this enzyme in staphylococcus aureus is 29.6 kd. the amount of penicillin hydrolyzed in 1 minute in a 10-ml solution containing 10-9 g of purified penicillinase was measured as a function of the concentration of penicillin. assume that the concentration of penicillin does not change appreciably during the assay. penicillin(μm) amount hydrolyzed(nmol) 1 0.11 3 0.25 5 0.34 10 0.45 30 0.58 50 0.61 (a) plot v0 versus [s] and 1/v0 versus 1/[s] for these data. does penicillinase appear to obey michaelis-menten kinetics? if so, what is the value of km? (b) what is the value of vmax? (c) what is the turnover number of penicillinase under these experimental conditions? assume one active site per enzyme molecule.

Paleontologists have found plant fossils deep within the layers of the north polar region. these leaf fossils have been labeled as to the rock layers they were found in, with the lower numbers being layers close to the earth's surface and higher numbers representing deeper layers. according to the numbers of these four leaf fossils, what might you infer?