1.
Viruses are not considered living things because they are not cellular and they .

do not have proteins
do not have genetic material
must have host cell to reproduce
can't mutate or change their DNA
2.
HIV wipes out a person’s immune system by attacking what types of cells?

B cells
skin cells
helper T cells
red blood cells
3.
People can have the rhinovirus more than once because .

they have no while blood cells
it hides then re-attacks later
the body can't make antibodies
there are many types of the virus

Air can be considered a mixture. which statement does not explain why?

Answer asap need to be answered by wednesday morning explain how a buffer works, using an ethanoic acid / sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.

Can anyone answer these questions? ? i need it before 1: 00pm today