In gel electrophoresis why does the dna move towards the bottom of the wall of gel?

a) dna is negatively charged
b) dna is positively charged
c) dna is extremely heavy
d) dna is less dense than air

Imagine ? person stepping on a pin and pulling his or her foot way look at the réfléchir arc of the scenarios below

How does science influence the decisions made about social, economic, and political issues?

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?