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

the match duh

explanation:

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.

b. read the phase at the intersection of any given temperature and pressure.

b. lithosphere, asthenosphere, mesosphere   is the answer most likely