Chapter 10 and 12.4- DNA Structures and Chromosomes

Question 1

What is the tetranucleotide hypothesis?

Answer 1

An incorrect hypothesis created by Leave that stated DNA contained equal amounts of all 4 nucleotides

Question 2

Deoxyribose has a _______ atom rather than a __________ _____ at the ___ position

Answer 2

hydrogen; hydroxyl; C-2’

Question 3

The ___ atom of the sugar is involved in the chemical linkage to the nitrogenous base.

Answer 3

C-1’

Question 4

If base is purine, ___ atom covalently bonds to sugar.

Answer 4

N-9

Question 5

A-T base pairs form _ hydrogen bonds

Answer 5

2

Question 6

C-G base pairs form _ hydrogen bonds

Answer 6

3

Question 7

If base pyrimidine, the __ atoms bonds to the sugar

Answer 7

N-1

Question 8

In DNA, the phosphate may be bonded to the __, __, or__ atom of the sugar.

Answer 8

C-2; C-3; C-5

Question 9

__ phosphate group is most common

Answer 9

C-5’

Question 10

Nucleotides are called what else?

Answer 10

Nucleoside monophosphate

Question 11

Describe a phosphodiester bond

Answer 11

A phosphate group linked by two sugars to link two mononucleotides

Question 12

Each phosphoric acid has been joined by _ _______ by an ____ _______ on both sides.

Answer 12

2 alcohols; ester linkage

Question 13

Short chains of 20 nucleotides are called?

Answer 13

oligonucleotides

Question 14

Histones contain large amounts of ________ charged _____ and ______ which makes it possible to bond to negatively charged phosphate groups in nucleotides.

Answer 14

positively; lysine; arginine

Question 15

Describe chromatin

Answer 15

They are composed of DNA and proteins and undergoes lots of coiling and folding as they condense in the cell nucleus

Question 16

What happens if histone molecules are chemically removed from the chromatin?

Answer 16

The regularity of diffraction pattern gets disturbed

Question 17

Chromatin is made up of ___________

Answer 17

nucleosomes

Question 18

Describe nucleosome core particles

Answer 18

They consist of 147 base pairs and are created when nuclease digestion time is extended. About 200 base pairs are removed from the nucleosome

Question 19

Describe Linker DNA

Answer 19

DNA lost in the process of creating nucleosome core particles

Question 20

Linker DNA is associated with histone __.

Answer 20

H1

Question 21

Describe the formation of nucleosomes

Answer 21

The 1st level of packing where the DNA helix reduces by 1/3 its original length by wrapping around histones

Question 22

Chromatin is packed into a thicker solid called _______.

Answer 22

solenoid

Question 23

Describe chromatin remodeling

Answer 23

Chromatin relaxing its compact structure and composing regions of DNA to regulatory proteins to allow replication and gene expression

Question 24

Nucleotides are linked by a phosphodiester bond between the phosphate group at the ___ position and the __ group on the __ position

Answer 24

C-5’; OH; C-3’

Question 25

Chromatin is bound up in nucleosomes with which histones?

Answer 25

H2A, H2B, H3, and H4.

Question 26

___________ is uncoiled and active, whereas ____________ remains condensed and is inactive.

Answer 26

Euchromatin; heterochromatin