The oxygen revolution changed earth’s environment dramatically. which of the following took advantage of the presence of free oxygen in the oceans and atmosphere?
a. the evolution of cellular respiration, which used oxygen to harvest energy from organic molecules
b. the persistence of some animal groups in anaerobic habitats
c. the evolution of photosynthetic pigments that protected early algae from the corrosive effects of oxygen
d. the evolution of chloroplasts after early protists incorporated photosynthetic cyanobacteria

An experienced goldfish breeder receives two unusual male goldfish. one is black rather than gold, and the other has a single tail fin rather than a split tail fin. the breeder crosses the black male to a female that is gold. all the f1 are gold. she also crosses the single-finned male to a female with a split tail fin. all the f1 have a split tail fin. she then crosses the black male to f1 gold females and, separately, crosses the single-finned male to f1 split-finned females. the results of the crosses are shown below. black male xf1 gold female: gold 32 black 34 single-finned male xf1 split-finned female: split fin 41 single fin 39a. what do the results of these crosses suggest about the inheritance of color and tail fin shape in goldfish? b. is black color dominant or recessive? explain. is single tail dominant or recessive? explain. c. use chi-squere analysis to test your hereditary hypothesis for each trait.