Answer:
The two strands are held together by hydrogen bonds between the bases, with adenine forming a base pair with thymine, and cytosine forming a base pair with guanine.
Explanation: hydrogen bonds
Mitosis allows cells to make copies of themselves
ANSWER
The correct answer is A
<u>EXPLANATION</u>
From the equation 
<u>L.H.S.</u>
Fe = 1
O =2
<u> R.H.S</u>
Fe =2
O =3
Now, let try to balance the oxygen atoms first,
To do this, we know the Least Common Multiples of 2 and 3 is 6
To get 6 atoms of oxygen at L.H.S multiply 2 by 3 and on the R.H.S, multiply 3 by 2
L.H.S.
R.H.S
This means that, 3 should be in front of
at the L.H.S and 2 should come before
in the R.H.S of the equation
Now, we have
L.H.S.
Fe = 1
O = 6
<u>R.H.S</u>
Fe =4
O =6
The equation is still not balanced since Fe is not balance
The Least Common Multiple of 1 and 4 is 4
Which means that we need to multiply 1 by 4 at the L.H.S and 4 by 1 at the R.H.S
L.H.S.
R.H.S
We now, have
<u>L.H.S. </u>
Fe= 4
O=6
<u>R.H.S</u>
Fe =4
O=6
Hence the balanced equation is

Hello. You did not enter the text to which these questions refer, which makes it impossible for them to be answered. However, I will try to help you in the best possible way.
It is only possible to answer your questions in a specific way by reading the experiment, however, I can inform you that formites are objects that allow the colonization and growth of microorganisms that can be major causes of diseases. Among these microorganisms are bacteria, fungi and viruses of the most varied species. Among these microorganisms, both fungi and non-demanding bacteria can grow in a nutrient agar culture medium. This is because this is a very simple culture medium where bacteria that do not need specific nutrients can grow and where most fungi can grow too. However, it is impossible for viruses to grow in this type of culture medium or in any culture medium, since viruses only develop inside a host's organism. Bacteria known as fastidious would also not grow in this type of culture medium, since they only grow with the presence of very specific nutrients.