Why does your heart never tire of constantly beating to pump blood throughout your body?

Why is citrate not available for micro collection?

Early treatment for mental illness involved because doctors believed that doing this would drain the mental illness out of the person’s body.

Why do rna viruses appear to have higher rates of mutation? a) rna nucleotides are more unstable than dna nucleotides.b) replication of their genomes does not involve proofreading.c) rna viruses can incorporate a variety of nonstandard bases.d) rna viruses are more sensitive to mutagens.