5.1 Study Guide

Question 1

Please explain Chargaff’s Rules.

Answer 1

Rule 1: In any double stranded DNA, the number or guanine units ~ cytosine and the number of adenine ~ thymine.

Rule 2: The relative amounts of A, C, G, and T varies from one species to the next - accounts for genetic diversity between species.

Question 2

What are all the nitrogenous bases?

Answer 2

Adenine, Thymine, Cytosine, and Guanine.

Question 3

What does A pair with?

Answer 3

T.

Question 4

What does C pair with?

Answer 4

G.

Question 5

If a species has approximately 31% C, please approximate the rest of the bases.

Answer 5

G = 31 %.
A = 19%.
T = 19%.

Question 6

Why does a virus infect genetic material into a host cell?

Answer 6

To make a copy of themselves.

Question 7

What type of bond holds the nucleotides together to create the sugar/phosphate backbone?

Answer 7

Covalent bonds.

Question 8

What type of bond connects the base pairs to hold 2 strands together?

Answer 8

Hydrogen bonds.

Question 9

Which bond is weaker? How might this fit the mechanism for copying DNA?

Answer 9

Hydrogen. We will get 2 strands from each other by taking apart the hydrogen bonds/ Sugar phosphate and backbones will remain intact.

Question 10

Nucleotides are bonded from phosphate to sugar between what ‘ and what ‘ carbons?

Answer 10

3’ and 5’.

Question 11

What does antiparallel mean?

Answer 11

They are running in opposite directions.

Question 12

Please state the word for the definition; they are running in opposite directions.

Answer 12

Antiparallel.