If a stream with a horizontal distance of 5 km begins at an elevation 200 m higher than where it ends, what is its stream gradient?

Did you know that a single bee would have to go to over 2 million flowers to make a single pound of honey?

Which of the following factors would not contribute to allopatric speciation? a) a population becomes geographically isolated from the parent population.b) the separated population is small, and genetic drift occurs.c) the isolated population is exposed to different selection pressures than the ancestral population.d) different mutations begin to distinguish the gene pools of the separated populations.e) gene flow between the two populations is extensive.

What are the pros and cons of quadrat sampling?