2: The Genetic Material

Question 0

What experiment did Griffith perform?

Answer 0

The transformation experiment. He used S, virulent and R, non-virulent bacteria to discover the transforming principle.

Question 1

What are the 4 requirements for genetic material?

Answer 1

1. Relatively stable
2. Replicate accurately
3. Capable of change
4. Able to be packaged

Question 2

What did avery, mcleod, and mccarty find?

Answer 2

DNA is the transforming agent.

Question 3

The hershy-chase experiment

Answer 3

Used E. Coli infected with bacteriophage t2

Question 4

How was RNA discovered as viral genetic material

Answer 4

In the tobacco mosaic virus

Question 5

What are the 3 components of a nucleotide?

Answer 5

1. A pentose (5-carbon) sugar
2. Nitrogenous base
3. Phosphate group

Question 6

What is the difference between ribose and deoxyribose?

Answer 6

Deoxyribose doesn’t have a 2’ hydroxyl group

Question 7

What is a nucleoside?

Answer 7

The sugar-base

Question 8

What is Chargaff’s rule?

Answer 8

The amount of purine is always equal to the amount of pyrimidine.

Question 9

Rosalind franklin’s x-ray diffraction images of dna showed….

Answer 9

A helical structure with regularities at 0.34 nm along axis of the molecule

Question 10

There are ____ base pairs per turn of the helix.

Answer 10

10

Question 11

The dna helix is ______-handed.

Answer 11

right

Question 12

The dna helix has _____ and _____ grooves that are important for _______ ________.

Answer 12

Major; minor; protein binding

Question 13

A-DNA

Answer 13

Right-handed, 10.9 per turn, short and wide

Question 14

B-DNA

Answer 14

Normal dna

Question 15

Z-DNA

Answer 15

Left-handed, 12 bp, elongated and thin

Question 16

How many bp in humans?

Answer 16

~3 billion

Question 17

A ______ in supercoiled dna will allow it to return to a relaxes dna circle.

Answer 17

nick

Question 18

What is the purpose of topoisomerase?

Answer 18

It supercoils dna

Question 19

What is the c-value?

Answer 19

The total amount of dna in the haploid chromosome of a species

Question 20

What is the c-value paradox?

Answer 20

The structural complexity and the c-value of an organism are not related

Question 21

The dna-protein complex is called _______ and it is highly conserved in all ________.

Answer 21

Chromatin; eukaryotes

Question 22

The 5 types of histones

Answer 22

1. H1
2. H2A
3. H2B
4. H3
5. H4

Question 23

How much dna relative to histones do chromosomes have?

Answer 23

An equal weight of both

Question 24

What charge do histones have?

Answer 24

Positive

Question 25

How much do histomes condense dna?

Answer 25

7x

Question 26

What does h1 do?

Answer 26

Connects nucleosomes, condensing dna another 6x

Question 27

What does the solenoid model propose?

Answer 27

Nucleosomes form a spiral with 6 nucleosomes per turn

Question 28

A fully condensed chromosome is _____x shorter and _____x thicker than a normal dna strand.

Answer 28

10,000; 400

Question 29

Over-twisting results in…

Answer 29

Positive supercoils

Question 30

Undertwisting and overtwisting are kinetically _______.

Answer 30

Unfavorable

Question 31

When does euchromatin condense?

Answer 31

With the cell cycle

Question 32

2 types of heterochromatin

Answer 32

1. Constitutive

2. Facultative

Question 33

What is constitutive heterochromatin?

Answer 33

heterochromatin that occurs at the same sites in both homologous chromosomes of a pair and consists mostly of repetitive dna. (e.g. centromeres)

Question 34

What is facultative heterochromatin?

Answer 34

Heterochromatin that varies between cell types or developmental stages etc.

Question 35

Uses of telomeres

Answer 35

Replication and stability

Question 36

Telomeres

Answer 36

Repeated sequences at the ends of dna strands. Consists of heterochromatin.

Question 37

Drosophila has a telomere composed of….

Answer 37

Transposons