Answer:
four billion years ago the earth had a layer of ozone gas
Answer:
D) the thylakoid and mitochondrial inner membranes.
Explanation:
Electron transport chain in plant cells is used for extracting sunlight energy via redox reactions through the process of photosynthesis. This process occurs in chloroplast (thylakoid membrane), where light energy is transformed into chemical energy, that leads to the conversion of water to oxygen and NADP+ to NADPH with transfer of H+ ions across chloroplast membranes. Formed H+ gradient is used for the ATP synthesis.
In all eukaryotes, including plants, electron transport chain is located in the inner mitochondrial membrane where it serves as the site of oxidative phosphorylation (production of ATP) through the action of ATP synthase.
Without enough light, a plant cannot photosynthesize very quickly - even if there is plenty of water and carbon dioxide and a suitable temperature. Increasing the light intensity increases the rate of photosynthesis, until some other factor - a limiting factor - becomes in short supply.
