C4 plants have evolved different photosynthetic mechanisms. these plants view available hint(s)
a) fix co2 into a four-carbon compound instead of a three-carbon compound
b) are adapted to living in cold, wet climates where there is no water shortage
c) do not fix co2 through the calvin cycle
d) conserve water more efficiently by shutting their stomata during the day
e) fix o2 instead of co2`

20 point pls brianliest 1. what does a red shift mean? blue shift? 2. describe the big bang theory. according to this theory, how old is the universe? 3. scientists believe the universe is expanding. what is the evidence that supports this? 4. describe a nebula. 5. describe the 3 types of galaxies. what is a barred spiral galaxy? 6. what is a light year? how far is alpha centauri from earth? 7. describe the universal law of gravitation. be sure to include gravitational force between two objects. 8. describe the planets’ orbits around the sun. 9. what is the asteroid belt? where is it located? 10. describe rotation and revolution of earth. what determines an earth day and year? 11. how do galaxies exist? 12. compare and contrast the inner and outer planets. 13. what causes the seasons?