21. CRISPR-Cas9 is a genetic modification technique that edits parts of the genome of an organism. Using this technique scientists can add, remove, or modify sections of the DNA sequence. How can scientists use this technique to control gene expression? O By activating or deactivating specific genes

O By calculating the number of genes different organisms produce

O By identifying how closely related one individual is to another

O By determining the number of chromosomes in an organsim

Time ! for a smell to begin the process of registering in your brain, first you must a) inhale odor molecules into the nasal cavity b)transduce scent chemicals c)have a scent to inhale d)all answers can work

Which phase of the cell cycle ensures that identical copies of the dna are made for daughter cells?

Me 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?