Before nitrogen can be used by living organisms, it must be converted to water-soluble:
(a) ammonia.
(b) nitrates.
(c) nitrites.
(d) nitrogenous wastes.

In german cockroaches, curved wing (cv) is recessive to normal wing (cv+). bill, who is raising cockroaches in his dorm room, finds that the frequency of the gene for curved wings in his cockroach population is 0.6. in his friend joe’s apartment, the frequency of the gene for curved wings is 0.2. one day joe visits bill in his dorm room, and several cockroaches jump out of joe’s hair and join the population in bill’s room. bill estimates that, now, 10% of the cockroaches in his dorm room are individual roaches that jumped out of joe’s hair. what is the new frequency of curved wings among cockroaches in bill’s room? 0.69 0.4 0.5 0.31 0.20

Which of the following sex and generation combinations directly produces the pollen tube of angiosperms? a) male gametophyteb) female gametophytec) male sporophyted) female sporophyte

The cluster of developing cells from conception until birth is called an