Eukaryotic cells contain certain structures that perform specialized functions for the cell. what are these structures called? a. cells b. organs c. tissues d. organelles

If bacteria are much too small to see, what is one reason why can we see colonies in the petri dishes that have plenty of food to eat after only a few days?

The picture represents a structure of the respiratory system. which is the function of this structure? to bring air into the body to exchange oxygen with carbon dioxide to carry air to the lungs to release oxygen from the body

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?