Why must most amphibians start their life in water

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 way do the nitrogenous bases in dna pair up? a. a and g; t and c b. a and c; t and g c. a and t; g and c d. a and a; t and t; g and g; c and c

Are the earth's ocean floor and continents the same age geologically? why or why not?