Chapter 10 DNA History and Replication

Question 1

What are the two components of the chromosome?

Answer 1

DNA and protein

Question 2

Until the 1940s, which component was believed to be the most likely candidate for the genetic material and why?

Answer 2

Proteins because they were more structurally complex and functionally specific

Question 3

Define pathogen

Answer 3

Disease causing agent

Question 4

What two things did Frederick Griffith observe when he killed pathogenic bacteria and mixed the remains with living harmless bacteria?

Answer 4

1. Some of the harmless bacteria became pathogenic

2. This bacteria passed the trait to its descendants

Question 5

What did Hershey and Chase determine was the genetic material of a T2 virus?

Answer 5

DNA

Question 6

What is a bacteriophage (phage)?

Answer 6

A bacterial virus

Question 7

What 2 things does a T2 phage consist of?

Answer 7

DNA and protein

Question 8

What did Alfred Hershey and Martha Chase conclude was the hereditary material?

Answer 8

DNA

Question 9

DNA are organic molecules called _________ which are made of monomers called ____________

Answer 9

Nucleic acids, nucleotides

Question 10

List the nitrogenous based found in DNA

Answer 10

Adenine(A), thymine(T), cytosine(C), and guanine(G)

Question 11

What are the 3 components of a nucleotide?

Answer 11

A nitrogenous base, sugar, and a phosphate group

Question 12

Which two components build the backbone of nucleic acids?

Answer 12

Sugar and phosphate

Question 13

Compare DNA and RNA

Answer 13

Sugar Nitrogen bases

DNA-deoxyribose thymine

RNA-ribose uracil

Question 14

What two scientists are credited with discovering the 3D structure of DNA?

Answer 14

James D. Watson and Francis Crick

Question 15

What contribution from Rosalind Franklin was valuable to Watson and Crick?

Answer 15

And X-ray crystallographic image

Question 16

What was Watson able to deduce from Rosalind Franklin’s x-ray image?

Answer 16

DNA is a double helix (helix with nitrogenous bases stacked about 1/3 of a nanometer apart)

Question 17

What term is now used to describe DNAs structure?

Answer 17

Double helix

Question 18

What are Chargaff’s rules?

Answer 18

The amount of adenine in the DNA of any 1 species was equal to the amount of thymine and that the amount of guanine was equal to the amount of cytosine

Adenine=thymine
Guanine=cytosine

Question 19

If a species has 35% adenine in its DNA, determine the percent of the other 3 bases.

Answer 19

Thymine-35%
Guanine-15%
Cytosine-15%

Question 20

What is the complementary sequence to the strand: GTAATC?

Answer 20

CATTAG

Question 21

A always pairs with ___ and G pairs with ____

Answer 21

T, C

Question 22

Describe the semi-conservative model of DNA replication.

Answer 22

Each of two daughter molecules add one old strand and one new strand of DNA

Question 23

Is DNA replication an accurate process or are many bases paired incorrectly?

Answer 23

Accurate, only 1 DNA nucleotide per several billion is incorrect

Question 24

Where does DNA replication begin?

Answer 24

Origins of replication

Question 25

List the functions of the enzymes:

DNA polymerase and DNA ligase

Answer 25

DNA polymerase-
1. Link DNA to growing daughter strand
2. Add to the 3’ end only
DNA ligase-links legates (pieces) into a single strand

Question 26

The daughter DNA strand can only grow in the ____ >____ direction

Answer 26

5’->3’

Question 27

What does DNA replication ensure?

Answer 27

All somatic cells in a multicellular organism carry the same genetic information

Question 28

What is the molecular connection between genotype and phenotype?

Answer 28

Proteins

Question 29

Define transcription

Answer 29

Transfer of genetic information from DNA into an RNA molecule