Arecent encyclopedia entry about dogs cites multiple research papers done by scientists at veterinary schools. according to the article, labrador retrievers come in two specific breeds: english and american. the english breed is described as stocky and heavy, while the american breed is described as tall and lanky. the article describes current scientific research as showing that males of both breeds usually weigh about 29-41 kg (65-90 lb), and females weigh 25-32 kg (55-70 lb). coat colors for both breeds come in solid black, yellow, or chocolate. all labs have strong tails and webbed feet, which them swim. devon would like to use this information to determine if his new dog is an english or american labrador retriever.

This is a situation in which genes are attached to an organism's sex chromosomes; the sex of an organism influences the expression of a gene.

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.

What is the next step in muscle contraction after the actin changes shape