To help your immune system prepare for diseases
The human heart has only 4 chambers. Left and right atria and left and right ventricles.
Nitrogenous bases, double stranded, made of nucleotides, adenine, thymine, cytosine, guanine, A pairs with T, G pairs with C
<span>The second statement is correct. Viruses can infect all cellular life forms, but each cellular species
can be infected by own limited specific range of viruses. Most viruses that harm
animals can not harm humans. But, some viruses can infect different species of mammals, for example both
bats and humans can be infected be rabies.</span>
