Chapter 8: The Structure, Replication, and Chromosomal Organization of DNA

Question 1

Who first purified nuclei from cells in the 1860s?

Answer 1

Friedrich Miescher.
The contents of the nuclei contained a substance he called nuclein

Question 2

What were identified as the carriers of genetic information in early 1900s?

Answer 2

Chromosomes

Question 3

Which scientists proved that DNA is the transforming factor between bacterial strains?

Answer 3

Griffiths and Avery, MacLeod, and McCarty

Question 4

Who proved that DNA is the genetic material in viruses?

Answer 4

Hershey and Chase

Question 5

What carries genetic information?

Answer 5

DNA not proteins

Question 6

Which type of virus kills bacteria?

Answer 6

Bacteriophages

Question 7

What are Bacteriophages made of?

Answer 7

Made up of only a protein coat and DNA

Question 8

How do Bacteriophages kill bacteria?

Answer 8

DNA enters bacterium, protein coat stays outside

Question 9

Name this bond

Answer 9

single covalent bond

Question 10

Name this bond

Answer 10

double covalent bond

Question 11

Name this bond

Answer 11

hydrogen bond

Question 12

Nucleotides are joined by covalent bonds to form what chains?

Answer 12

polypeptide chains

Question 13

What are the three components of nucleotide building blocks?

Answer 13

1. Nitrogen-containing base
   - Purines (A and G)
   - Pyrimidines (C and T)
2. Sugar
   - Deoxyribose
3. Phosphate group

Question 14

Name this structure

Answer 14

Adenine (A)

Question 15

Name this structure

Answer 15

Thymine ( T ) (in DNA)

Question 16

Name this structure

Answer 16

Uracil (U) (in RNA)

Question 17

Name this structure

Answer 17

Guanine (G)

Question 18

Name this structure

Answer 18

Cytosine (C)

Question 19

Name this structure

Answer 19

Deoxyribose (in DNA)

Question 20

Name this structure

Answer 20

Ribose (in RNA)

Question 21

Name this structure

Answer 21

Phosphate group

Question 22

In the DNA double helix, where are the phosphate groups located?

Answer 22

phosphate groups on the outside of the helix

Question 23

In the DNA double helix, where are the bases located?

Answer 23

bases stacked inside the helix

Question 24

How is the DNA twisted ladder confirmation described?

Answer 24

• Two polynucleotide strands (“rails”), held together by hydrogen bonding between the bases (“rungs”)
• The strands are oriented in opposite directions

Question 25

In DNA, base A pairs with

Answer 25

T

Question 26

In DNA, base G pairs with

Answer 26

C

Question 27

The two polynucleotide chains in DNA run in what direction?

Answer 27

opposite direction

Question 28

Where is genetic information stored in DNA?

Answer 28

Four bases allows for a high coding capacity

Question 29

What is the complete set of genetic information for a given organism?

Answer 29

its genome; genome size is species-specific

Question 30

Any change to the linear sequence of DNA that can result in an altered phenotype is called a

Answer 30

mutation

Question 31

Complementary sequence of the two strands explains how DNA can be

Answer 31

replicated

Question 32

What type of bonds joins nucleotides in RNA to form polypeptide chains?

Answer 32

covalent bonds

Question 33

Is RNA single-stranded?

Answer 33

yes, folds upon itself

Question 34

What is the function of RNA?

Answer 34

Transfer of genetic information from the nucleus to the cytoplasm, protein synthesis, and gene expression

Question 35

Term describing how each daughter molecule receives one old DNA strand and one newly synthesized DNA strand in DNA replication?

Answer 35

Semiconservative replication. Both strands serve as templates for synthesis of a new, complementary strand

Question 36

Which direction does DNA proceed in replication?

Answer 36

Proceeds in a 5’ to 3’ direction

Question 37

In which phase of the cell cycle does DNA replication occur?

Answer 37

S phase in the cell cycle

Question 38

What creates a template for the synthesis of a new DNA strand in replication?

Answer 38

The two polynucleotide strands uncoil.

Question 39

Why is three-dimensional structure of chromosomes is important?

Answer 39

- ~2m of DNA must fit inside a nucleus with a 5μm diameter - Chromosomes uncoil and recoil during the cell cycle - Spatial arrangement of DNA is important for the regulation of gene expression

Question 40

Within chromosomes, DNA is coiled around clusters of what?

Answer 40

histones to form nucleosomes

Question 41

How does a genome fit inside a nucleus?

Answer 41

extensive coiling

Question 42

What are short, repeated sequences at chromosome tips?

Answer 42

telomeres

Question 43

During DNA replication, some repeats of telomeres are left uncopied, leading to

Answer 43

shortened telomeres with each cell division

Question 44

What defines the spindle attachment site?

Answer 44

Centromeres

Question 45

What does the location of the centromere contribute to?

Answer 45

the unique shape of any given chromosome

Question 46

Chromosomes are located in

Answer 46

Specific territories in the nucleus. Chromosome territories are linked to function.