An amoeba is a single-celled organism that feeds on algae, plant cells, and bacteria. When an amoeba feeds, it first makes contact with the food particle. Next, the amoeba starts to surround the particle. Once the particle is completely engulfed, it is surrounded by a layer of the amoeba's membrane, forming a vesicle. The pH in the vesicle is then lowered and the contents are degraded.

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?