The photosynthetic dinoflagellates called zooxanthellae have a relationship with the corals in which they live.

Evolution acts upon the population of organisms and not on each individual organism

When it is summer at the south pole, a. the northern hemisphere is tilted toward the sun. b. the southern hemisphere is tilted away from the sun. c. the northern hemisphere is tilted away from the sun. d. both the southern and northern hemispheres are tilted toward the sun.

How did the average and range of beak size differ between birds that survived the drought and birds that dies?