Genetics #1

Question 1

the structure of DNA made up of?

Answer 1

Repeating units of nucleotides (monomers)

Question 2

What are the 3 components of a nucleotide?

Answer 2

Back:_ 1. Sugar group, 2. Phosphate group, 3. Nitrogenous base

Question 3

What is the sugar group in DNA composed of?

Answer 3

Deoxyribose, a five-carbon sugar molecule

Question 4

What is the phosphate group in DNA?

Answer 4

A phosphate molecule that forms a phosphodiester bond with the sugar molecule

Question 5

What are the 4 nitrogenous bases in DNA?

Answer 5

. Adenine (A), 2. Guanine (G), 3. Cytosine (C), 4. Thymine (T)

Question 6

What is the base pairing rule in DNA?

Answer 6

Adenine (A) pairs with Thymine (T), Guanine (G) pairs with Cytosine (C)

Question 7

How does the deoxyribose sugar bind with phosphate?

Answer 7

At both its 3’ and 5’ (three prime and five prime) carbons

Question 8

What is the significance of 3’ and 5’ carbons in DNA structure?

Answer 8

They are the binding sites for phosphate groups, forming phosphodiester bonds between nucleotides

Question 9

What is the result of deoxyribose binding with phosphate at 3’ and 5’ carbons?

Answer 9

Back:_ Formation of a phosphodiester bond, linking nucleotides together in a polynucleotide chain (DNA)

Question 10

What attaches to the deoxyribose sugar group?

Answer 10

A nitrogenous base

Question 11

What are the two main forms of nitrogenous bases?

Answer 11

Pyrimidines and Purines

Question 12

Which nitrogenous bases are pyrimidines?

Answer 12

Thymine (T) and Cytosine (C)

Question 13

Which nitrogenous bases are purines?

Answer 13

Adenine (A) and Guanine (G)

Question 14

What is the difference in chemical structure between Pyrimidines and Purines?

Answer 14

Pyrimidines have a single ring,

while Purines have a double ring

Question 15

Which Pyrimidines have a single ring structure?

Answer 15

Thymine (T) and Cytosine (C)

Question 16

What is the chemical structure of Purines?

Answer 16

Back: Two fused rings

Question 17

Which Purines have a two-fused-ring structure?

Answer 17

Adenine (A) and Guanine (G)

Question 18

What enzyme opens up the DNA at the replication fork?

Answer 18

Helicase

Question 19

What proteins coat the DNA around the replication fork?

Answer 19

Single-strand binding proteins (SSBs)

Question 20

What is the function of SSBs?

Answer 20

To prevent rewinding of the DNA

Question 21

What enzyme works ahead of the replication fork?

Answer 21

Topoisomerase

Question 22

What is the function of Topoisomerase?

Answer 22

To prevent supercoiling

Question 23

What enzyme synthesizes RNA primers?

Answer 23

Primes

Question 24

What is the function of RNA primers?

Answer 24

To provide a starting point for DNA synthesis

Question 25

What enzyme extends the primers and makes the bulk of the new DNA?

Answer 25

DNA Polymerase III

Question 26

What enzyme removes RNA primers and replaces them with DNA?

Answer 26

DNA Polymerase I

Question 27

What enzyme seals the gaps between DNA fragments?

Answer 27

DNA Ligase

Question 28

Can add DNA bases at 5’ end

Answer 28

Telomerase

Question 29

Removes section of RNA primer and replaces with DNA nucleotide

Answer 29

DNA Polymerase I