Unit 12: DNA Replication And Manipulation

Question 1

DNA Replication

Answer 1

The process of duplicating a DNA molecule

Question 2

Template Strand

Answer 2

Strand of DNA that serves as a model for the synthesis of a daughter strand

Question 3

Daughter Strand

Answer 3

Strand of DNA that gets copied from template strand

Question 4

Semiconservstive Replication

Answer 4

After each replication, each new DNA duplex will consist of one strand that was present in parental duplex and one newly synthesized strand

Question 5

Replication Fork

Answer 5

Both daughter strands should grow in length by the addition of nucleotides near the site where the parental strands separate

Question 6

DNA Polymerase

Answer 6

An enzyme that carries out DNA replication

Question 7

Leading Strand

Answer 7

The daughter strand whose 3’ end points toward the replication fork so that as the parental double helix unwinds, the daughter strand can be synthesized as one long continuous polymer

Question 8

Lagging Strand

Answer 8

A daughter strand whose 5’ end is near the replication forks and DNA is synthesized in short, discontinuous pieces

Question 9

Okazaki Fragments

Answer 9

The short pieces in the lagging strand

Question 10

Primer

Answer 10

A short stretch of RNA that serves as a starter for DNA synthesis

Question 11

RNA Primase

Answer 11

An RNA polymerase that synthesizes a short piece of RNA complementary to the DNA template

Question 12

DNA Ligase

Answer 12

An enzyme that removes the RNA primer and replaces it with DNA nucleotides

Question 13

Proofreading

Answer 13

The process by which an incorrect nucleotide is removed after it is incorporated

Question 14

Helicase

Answer 14

Unwinds the parental double helix at the replication fork

Question 15

Single-Stranded Binding Proteins

Answer 15

Binds the resulting single-stranded regions of DNA to prevent the template strands from coming back tougher

Question 16

Topoisomerase II

Answer 16

Relieves the stress on the double helix that results from its unwinding at the replication fork

Question 17

Origin of Replication

Answer 17

Points at which DNA synthesis is initiated

Question 18

Replication Bubble

Answer 18

Forms from the opening of the double helix at each origin of replication

Question 19

Telomere

Answer 19

The end of a eukaryotic chromosome that is capped by a repeating sequence repeated over again in about 1500-3000 copies

Question 20

Telomerase

Answer 20

Enzyme that replaces the lost telomere repeats

Question 21

Germ Cells

Answer 21

Cells consisting of sperm or eggs

Question 22

Stem Cells

Answer 22

Undifferentiated cells

Question 23

Somatic Cells

Answer 23

Cells active in the body

Question 24

Polymerase Chain Reaction (PCR)

Answer 24

A method for making copies of a piece of DNA which allows a targeted region of a DNA molecule to be replicated into as many copies as desired

Question 25

PCR Procedure Steps

Answer 25

1. At least one molecule of double-stranded DNA containing the region to be amplified serves as the template for amplification 2. DNA polymerase is used to replicate DNA 3. Deoxyribonucleoside triphosphates with bases A, T, G, and C are used as the building blocks for new DNA strands 4. Two short sequences of single-stranded DNA are required for DNA polymerase to start. Enough primer is added so the number of primer DNA molecules is greater than the number of template DNA molecules

Question 26

Oligonucleotides

Answer 26

The primer sequences produced by chemical synthesis and are about 20-30 nucleotides long

Question 27

Denaturation

Answer 27

A solution containing double-stranded DNA is heated into two individual strands

Question 28

Annealing

Answer 28

When the solution is cooled, the two primers anneal to their complementary sequence on the DNA template strands

Question 29

Extension

Answer 29

DNA polymerase synthesizes new DNA strands by extending primers in a 5’ to 3’ direction

Question 30

Gel Electrophoresis

Answer 30

A procedure done to determine the actual size of a DNA fragment by inserting DNA samples into slots and immersed in a solution that allows an electric current to be passed through it and DNA molecules move according to their size

Question 31

Restriction Enzymes

Answer 31

Enzymes that cleaves DNA at specific nucleotide sequences

Question 32

Restriction Sites

Answer 32

Sites where restriction enzymes cleave DNA

Question 33

Palindromic

Answer 33

The sequence of the top strand of DNA is the same as the bottom sequence

Question 34

Renaturation

Answer 34

Allows complementary strands to come together again

Question 35

Probe

Answer 35

A small DNA fragment used to determine whether or not a sample of double-stranded DNA contains sequences that are complementary to it

Question 36

Southern Blot

Answer 36

Process by which DNA molecules get cut using restriction enzymes, the DNA segments undergo gel electrophoresis where the segments get transferred to filter paper and get shone with light or become raditoactive and the presence of bands indicates the number and size of DNA fragments complementary to probe

Question 37

Dideoxynucleotide

Answer 37

The 3’ hydroxyl group on the sugar ring is absent

Question 38

Chain Terminator

Answer 38

The presence of a dideoxynucleotide that stops strand growth

Question 39

Sanger Sequencing

Answer 39

A processes incorporating dideoxynucleotides to daughter strands that determines the DNA template