13. photosynthesis a. electron transport chain b. Stage 3 14. Stage 2 c. Krebs cycle 15. ATP and NADPH formed d. acetyl-CoA formation 16. acetyl-CoA formation e. radiant energy 17. Krebs cycle f. Stage 1 g. glycolysis h. cellular respiration i. Calvin cycle j. light reactions

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

supercell thunderstorms are perhaps the most violent of all thunderstorm types, and are capable of producing damaging winds, large hail, and weak-to-violent tornadoes

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.