14. which of the following is not caused by a virus?
a. acquired immune deficiency syndrome
b. herpes
c. gonorrhoea
d. influenza (the flu)

The “ecological footprint” left by a citizen of a developed nation is about four times larger than that left by a citizen of a developing nation. why is this the case?

Abird flies by moving its wings up and down. which two systems are most directly responsible for the movement of a bird's wings? a. skeletal and muscular systems b. respiratory and muscular systems c. skeletal and digestive systems d. respiratory and digestive systems

You sample a population of butterflies and find that 56% are heterozygous at a particular locus. what should be the frequency of the recessive allele in this population?