Large amounts of oxygen gas appeared in earth's atmosphere about 2.7 bya years ago, a. after photo-autotrophic prokaryotes evolved b. after eukaryotes evolved c. before anaerobic organisms evolved d. after the first organisms colonized land

After eukaryotes organisms evolved

after photo-autotrophic prokaryotes evolved

a neutral ph of 7 and normal organism temperature is needed for a certain enzyme to be effective.  

what would happen to the enzyme if the ph and/or temperature fluctuate greatly from the norm?  

a.the enzyme’s hydrogen bonds will break.  

b.the activation energy will increase.  

c.more product will be formed.

d.the ideal temperature and ph for the enzyme function will decrease.  

fabric is silk wool ext. paper isnt

explanation:

u cant make fabric out of paper cause paper comes from wood while fabric comes from animals