Molecular Basis of Inheritance

Question 1

________ is DNA and not RNA, proteins or any other biological compound

Answer 1

The genetic material

Question 2

Genetic material was shown in a series of experiments between what years?

Answer 2

1928-1952

Question 3

DNA is composed of:

Answer 3

-one sugar, 2-deoxyribose

-four nitrogenous bases:
purines A and G
pyrimidines T and C

-phosphate groups

Question 4

Sugar + base + phosphate =

Answer 4

= nucleotide

Question 5

Nucleoside consists of a ___ + _____

Answer 5

sugar and base

Question 6

A phosphate group consists of ____ + ___

Answer 6

1 P and 4 O’s

Question 7

What are the nitrogenous bases?

Answer 7

A, G, C, T

Question 8

The phosphate is attached to the –OH on the ____

Answer 8

no. 5 carbon of the sugar, the 5´ C

Question 9

The –OH on the no. 3 carbon of the sugar, the 3´ C,

Answer 9

is free

Question 10

Sugar in DNA

Answer 10

deoxyribose

Question 11

Sugar in RNA

Answer 11

Ribose

Question 12

the purines in DNA and RNA

Answer 12

adenine (A) & guanine (G)

Question 13

the pyrimidines in DNA and RNA

Answer 13

cytosine (C), thymine (T) in DNA & uracil (U) in RNA

Question 14

DNA and RNA are polynucleotides made by linking nucleotides end-to-end by what process?

Answer 14

dehydration synthesis

Question 15

The covalent bonds linking the adjacent sugars are called _____

Answer 15

phosphodiester bonds

Question 16

The chain has a regular _____ backbone

Answer 16

sugar-phosphate

Question 17

One end has a phosphate on ____

Answer 17

a 5 carbon end

Question 18

The other end has an –OH on ____

Answer 18

a 3´ carbon

Question 19

____ is exclusively double-stranded, com-posed of two polynucleotide chains

Answer 19

DNA

Question 20

____ may be either single-stranded or double-stranded

Answer 20

RNA

Question 21

DNA forms a double helix, first proposed by who and when?

Answer 21

Watson and Crick in 1953

Question 22

helix is ___ handed

Answer 22

right

Question 23

bases are located where on DNA?

Answer 23

Center

Question 24

They are flat and stacked like rungs in a twisted ladder

Answer 24

Bases

Question 25

What is the DNA backbone?

Answer 25

The “backbone” is (deoxyribose-phosphate)n

Question 26

The bases on the opposite strands form ______ with each other

Answer 26

H bonds

Question 27

what are A to T with 2 (A=T), G to C with 3 (G=-C)?

Answer 27

Base pairs

Question 28

A&T and G&C must be what to eachother?

Answer 28

complementary

Question 29

- The 2 strands have the opposite orientation | - One runs 5´ to 3´, the other 3´ to 5´

Answer 29

Anti-parallel

Question 30

There are ___ base pairs in one complete turn of the helix

Answer 30

10

Question 31

The helix makes one turn every __ nm (__ Å

Answer 31

3.4, 34

Question 32

The distance between adjacent base pairs is thus __ nm (__ Å)

Answer 32

0.34, 3.4

Question 33

The diameter of the helix is __ nm (__ Å

Answer 33

2.0, 20

Question 34

The two strands separate and each serves as the template for the synthesis of a new strand during what phase?

Answer 34

S Phase

Question 35

Each “daughter” double helix consists of one ____ strand and one ____ strand

Answer 35

“old”, “new”

Question 36

DNA replication is thus said to be ____________

Answer 36

semiconservative

Question 37

_____ are added to the 3´ end of the chain

Answer 37

dNTPs

Question 38

The chain grows in the _____ direction

Answer 38

5´ to 3´

Question 39

enzymes that add dNTPs to the growing chain are called:

Answer 39

DNA polymerases

Question 40

In E. coli, there are three types of enzymes, called:

Answer 40

DNA polymerases I, II and III

Question 41

All three enzymes add _____ to the 3´ end of the chain, extending it in the 5´ to 3´ direction

Answer 41

dNTPs

Question 42

Most of the new DNA is made by:

Answer 42

DNA polymerase III

Question 43

On the _____, new DNA is made as one long continuous strand

Answer 43

leading strand

Question 44

On the lagging strand, however, new DNA is made in pieces called:

Answer 44

Okazaki fragments

Question 45

 _______ was a pioneer Japanese molecular biologist, known for his pioneer research on DNA replication

Answer 45

Reiji Okazaki 

Question 46

Ultimately, the Okazaki fragments are joined into one long continuous strand by the enzyme called:

Answer 46

DNA ligase

Question 47

DNA replication starts at a point on the DNA called the:

Answer 47

origin of replication

Question 48

Replication proceeds in what direction?

Answer 48

both

Question 49

The place where replication is occurring is called: | -There will be 2 moving away from origin

Answer 49

the replication fork

Question 50

On one side of each replication fork, DNA is made in the same direction the fork moves; The new DNA made on this side of the fork is called:

Answer 50

the leading strand

Question 51

The new DNA made on this side of the fork is called the lagging strand; The new DNA made on this side of the fork is called:

Answer 51

the lagging strand

Question 52

The lagging strands must be made in segments called:

Answer 52

Okazaki fragments

Question 53

Okazaki fragment 1 is made, the fork moves.....

Answer 53

....fragment 2 is made, and so on

Question 54

Eventually all the Okazaki fragments will be joined to make one long continuous strand by an enzyme called:

Answer 54

DNA ligase

Question 55

DNA polymerases cannot add the first dNTP in a new strand; | That’s done by an enzyme called ___ which makes a short primer of RNA

Answer 55

primase

Question 56

Eventually, the primer is removed by _____, which replaces it with DNA

Answer 56

DNA polymerase I