Which of the following best explains why cells that contain the same genetic material do not develop into the same types of cells? A. Because chemical signals that are released during the cell cycle can result in the linking of similar genes
B. Because internal or external stimuli can trigger the activation of specific genes in the DNA of cells
C. Because messenger RNA is converted to transfer RNA when cell differentiaton begins
D. Because random mutations can occur in the DNA of cells during early embryonic development ​

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?