Answer:
5
Explanation:
Nucleus is the center or "CEO" of the cell, that holds the cell's DNA and controls the cells' function.
Answer:b.CaCl2
Explanation:
A compound is a substance resulting when two or more elements are are chemically bonded together either ionically or covalently in a fixed ratio.
From the given options we can see that the only compound there is CaCl2 which is an ionic compound in the fixed ratio of one calcium ion to two chloride ions.
Other options , Cu,Na and Nd are merely pure substance---Elements
Answer: The pH of an aqueous solution of .25M acetic acid is 2.7
Explanation:

cM 0 0
So dissociation constant will be:

Give c= 0.25 M and
= ?

Putting in the values we get:


![[H^+]=c\times \alpha](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3Dc%5Ctimes%20%5Calpha)
![[H^+]=0.25\times 0.0084=0.0021](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D0.25%5Ctimes%200.0084%3D0.0021)
Also ![pH=-log[H^+]](https://tex.z-dn.net/?f=pH%3D-log%5BH%5E%2B%5D)
![pH=-log[0.0021]=2.7](https://tex.z-dn.net/?f=pH%3D-log%5B0.0021%5D%3D2.7)
Thus pH is 2.7
Answer:

Explanation:
The metabolic pathway by which energy can be obtained from a fatty acid is called <u>"beta-oxidation"</u>. In this route, acetyl-Coa is produced by removing <u>2 carbons</u> from the fatty acid for each acetyl-Coa produced. In other words, for each round, 1 acetyl Coa is produced and for each round 2 carbons are removed from the initial fatty acid. Therefore, the first step is to calculate the <u>number of rounds</u> that will take place for an <u>18-carbon fatty</u> acid using the following equation:

Where "n" is the <u>number of carbons</u>, in this case "18", so:

We also have to calculate the amount of Acetyl-Coa produced:

Now, we have to keep in mind that in each round in the beta-oxidation we will have the <u>production of 1
and 1
</u>. So, if we have 8 rounds we will have 8
and 8
.
Finally, for the total calculation of ATP. We have to remember the <u>yield for each compound</u>:
-)
-) 
-) 
Now we can do the total calculation:

We have to <u>subtract</u> "2 ATP" molecules that correspond to the <u>activation</u> of the fatty acid, so:

In total, we will have 128 ATP.
I hope it helps!