<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>
Answer:
All of the answer options are correct.
Explanation:
Chargaff contributed in understanding the structure and composition of DNA with his discoveries. He discovered that purine and pyrimidine bases are in equal amounts in a DNA molecule. He also discovered that amount of Adenine base (A) is equal to amount of Thymine base (T). It means that A pairs with T. Since A is a purine and T is a pyrimidine it also implies that purine base pairs with a pyrimidine base. This conclusion can also be arrived by taking in consideration the other base pair which is G (purine) and C (pyrimidine).
I believe it is A as well
A normal range in adults is generally considered to be 4.35 to 5.65 million red blood cells per microliter (mcL) of blood for men and 3.92 to 5.13 million red blood cells per mcL of blood for women. In children, the threshold for high red blood cell count varies with age and sex.