Birds fly south in winter because of __(blank)__. a) circadian rhythms
b) biological clocks
c) chronobiology
d) entrainment

Why do mutations in genes affect traits? o a. genes determine what type of mutagens an organism has. o b. genes produce proteins that cause traits. o c. genes affect how many chromosomes an organism has o d. genes code for carbohydrates that influence traits.

Choose the molecule that is described by each phrase. energy used during long activities:

Does mitochondria still meet the definition of a eukaryote why or why not?