Cahapter 12: DNA

Question 1

Adenine

Answer 1

(A) a compound which is one of the four constituent bases of nucleic acids. A purine derivative, it is paired with thymine in double-stranded DNA.

Question 2

Bacteriophage

Answer 2

a virus that parasitizes a bacterium by infecting it and reproducing inside it.

Question 3

Base

Answer 3

The nucleobase of a nucleotide involved in base pairing, as of a DNA or RNA polymer

Question 4

Complementary Base Pair

Answer 4

the phenomenon where in DNA guanine always hydrogen bonds to cytosine and adenine always binds to thymine.

Question 5

Cytosine

Answer 5

(C) a compound found in living tissue as a constituent base of nucleic acids. It is paired with guanine in double-stranded DNA.

Question 6

Deletion Mutation

Answer 6

a mutation in which a part of a chromosome or a sequence of DNA is lost during DNA replication. Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome.

Question 7

DNA Helicase

Answer 7

are essential during DNA replication because they separate double-stranded DNA into single strands allowing each strand to be copied.

Question 8

DNA Ligase

Answer 8

a specific type of enzyme, a ligase, that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond.

Question 9

DNA Polymerase

Answer 9

an enzyme that synthesizes DNA molecules from deoxyribonucleotides, the building blocks of DNA. These enzymes are essential for DNA replication and usually work in pairs to create two identical DNA strands from a single original DNA molecule.

Question 10

DNA Replication

Answer 10

is the process by which DNA makes a copy of itself during cell division. The first step in DNA replication is to ‘unzip’ the double helix structure of the DNA molecule

Question 11

Double Helix

Answer 11

a pair of parallel helices intertwined about a common axis, especially that in the structure of the DNA molecule.

Question 12

Free Nucleotide

Answer 12

A free, unincorporated nucleotide usually exists in a triphosphate form; that is, it contains a chain of three phosphates. … In this manner, each strand of DNA has a “backbone” of phosphate-sugar-phosphate-sugar-phosphate

Question 13

Guanine

Answer 13

(G) one of the four constituent bases of nucleic acids. A purine derivative, it is paired with cytosine in double-stranded DNA.

Question 14

Insertion Mutation

Answer 14

the addition of one or more nucleotide base pairs into a DNA sequence

Question 15

Inversion

Answer 15

a chromosome rearrangement in which a segment of a chromosome is reversed end to end. An inversion occurs when a single chromosome undergoes breakage and rearrangement within itself

Question 16

Mutation

Answer 16

he alteration of the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA.

Question 17

Nucleotide

Answer 17

a compound consisting of a nucleoside linked to a phosphate group. Nucleotides form the basic structural unit of nucleic acids such as DNA.

Question 18

Nucleotide Substitution Mutation

Answer 18

a single nucleotide base is changed, inserted or deleted from a sequence

Question 19

Semiconservative Replication

Answer 19

the mechanism of DNA replication in all known cells. t produces two copies of the original DNA molecule, each of which contains one of original strand, and one newly-synthesized strand.

Question 20

Sugar-Phosphate Backbone

Answer 20

an important stuctural component of DNA. It consists of 5-carbon deoxyribose sugars and phosphate groups

Question 21

Thymine

Answer 21

a compound which is one of the four constituent bases of nucleic acids. A pyrimidine derivative, it is paired with adenine in double-stranded DNA.

Question 22

Translocation

Answer 22

a phenomenon that results in unusual rearrangement of chromosomes.