AP BIOLOGY

Detailed explanation-1: -Cyanobacteria are a distinct group of bacteria that perform oxygenic photosynthesis. They have specialized internal membranes called thylakoid membranes in which photosynthetic systems reside.

Detailed explanation-2: -These endosymbiotic cyanobacteria in eukaryotes then evolved and differentiated into specialized organelles such as chloroplasts, chromoplasts, etioplasts, and leucoplasts, collectively known as plastids. Cyanobacteria are the first organisms known to have produced oxygen.

Detailed explanation-3: -Chloroplasts are the prominent organelles of green plant tissue. According to the widely accepted endosymbiotic theory [1] they originated from an ancient cyanobacterium, which was engulfed by a eukaryotic host cell.

Detailed explanation-4: -In plants and algae, which developed much later, photosynthesis occurs in a specialized intracellular organelle-the chloroplast. Chloroplasts perform photosynthesis during the daylight hours. The immediate products of photosynthesis, NADPH and ATP, are used by the photosynthetic cells to produce many organic molecules.

Detailed explanation-5: -In plants, photosynthesis takes place in chloroplasts, which contain the chlorophyll. Chloroplasts are surrounded by a double membrane and contain a third inner membrane, called the thylakoid membrane, that forms long folds within the organelle.