A researcher adds an enzyme to a sample of human DNA to see if the DNA changes. Which result would best support the conclusion that the
enzyme had no effect on the DNA?
.
A. The DNA has uracil bases.
B. The DNA has unpaired nitrogenous bases.
C. The DNA has a single strand with nucleotides and a sugar-phosphate backbone.
D. The DNA has a double helix shape with nucleotide pairs and sugar-phosphate
backbones.

80 points pls brainliest 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?