Which statement correctly describes how the amount of oxygen in the Earth's atmosphere has changed over time a. oxygen started to accumulate in the atmosphere before photosynthesis first evolve

b. oxygen said to accumulate in the atmosphere after photosynthesis first evolved

c. oxygen started to become scarcer in the atmosphere after first episode

d. large amounts of oxygen were present in the atmosphere both before and after photosynthesis first evolved

What is the volume of a book that has a width of 10 cm a length that is 2 times the width and a height that is half they would remember to express your answer in keeping units

Whenever diploid populations are in hardy-weinberg equilibrium at a particular locus a) the allele's frequency should not change from one generation to the next, but its representation in homozygous and heterozygous genotypes may change. b) natural selection, gene flow, and genetic drift are acting equally to change an allele's frequency. c) this means that, at this locus, two alleles are present in equal proportions. d) the population itself is not evolving, but individuals within the population may be evolving.

Water diffusing through a semipermeable membrane is called