AP BIOLOGY

Detailed explanation-1: -The hypothesis that eukaryotic cells evolved from a symbiotic association of prokaryotes-endosymbiosis-is particularly well supported by studies of mitochondria and chloroplasts, which are thought to have evolved from bacteria living in large cells.

Detailed explanation-2: -The first bacteria to appear on Earth, some 3.8 billion years ago, had no choice but to be anaerobic, because the atmosphere at that time contained no oxygen.

Detailed explanation-3: -Solution: Flocs contain aerobic living organisms of both eukaryotes (fungi) and prokaryotes (bacteria).

Detailed explanation-4: -Glycolysis is the first step in the breakdown of glucose to extract energy for cellular metabolism. Nearly all living organisms carry out glycolysis as part of their metabolism. The process does not use oxygen and is therefore anaerobic. Glycolysis takes place in the cytoplasm of both prokaryotic and eukaryotic cells.