Chapter 16 - Molecular Basis of Inheritance

Question 1

The process by which a DNA molecule is copied; also called DNA synthesis

Answer 1

DNA replication

Question 2

A change in genotype and phenotype due to the assimilation of external DNA by a cell

Answer 2

Transformation

Question 3

An infectious particle incapable of replicating outside of a cell, consisting of an RNA or DNA genome surrounded by a protein coat (capsid); some also have a membranous envelope

Answer 3

Virus

Question 4

The form of native DNA, referring to its two adjacent antiparallel polynucleotide strands wound around an imaginary axis into a spiral shape

Answer 4

Double Helix

Question 5

Referring to the arrangement of the sugar-phosphate backbones in a DNA double helix (they run in opposite 5’ –> 3’ directions).

Answer 5

Antiparallel

Question 6

Type of DNA replication in which the replicated double helix consists of one old strand derived from the parental model and one newly made strand

Answer 6

Semiconservative model

Question 7

Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides

Answer 7

Origins of replication

Question 8

A y-shaped region on a replicating DNA molecule where the parental strands are being unwound and new strands are being synthesized

Answer 8

Replication Fork

Question 9

Enzymes that untwist the double helix of DNA at replication forks, separating the two strands and making them available as template strands

Answer 9

Helicases

Question 10

A protein that binds unpaired DNA stands during DNA replication, stabilizing them and holding them apart while they serve as templates for the synthesis of complementary strands of DNA

Answer 10

Single-Strand Binding Proteins (SSB Proteins)

Question 11

A protein that breaks, swivels, and rejoins DNA stands. During DNA replication, it helps relieve strain in the double helix ahead of the replication fork.

Answer 11

Topoisomerase

Question 12

A short stretch of RNA with a free 3’ end bound by complementary base pairing to the template strand and elongated with DNA nucleotides during DNA replication

Answer 12

Primer

Question 13

Enzyme that joins RNA nucleotides to make a primer during RNA replication, using the parental DNA strand as a template

Answer 13

Primase

Question 14

Enzyme that catalyzes the elongation of new DNA (for example, the replication fork) by the addition of nucleotides to the 3’ end of an existing chain. There are several different types of this enzyme - #1 and 3 play major roles in DNA replication in E. Coli.

Answer 14

DNA Polymerase

Question 15

The new complementary DNA strand synthesized continuously along the template strand toward the replication fork in the mandatory 5’ –> 3’ direction

Answer 15

Leading strand

Question 16

A discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5’ –> 3’ direction away from the replication fork

Answer 16

Lagging strand

Question 17

A short segment of DNA synthesized away from the replication fork on a template strand during DNA replication. Many such segments are joined together to make up the lagging strand of newly synthesized DNA.

Answer 17

Okazaki Fragments

Question 18

A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3’ end of one DNA fragment (such as an Okazaki fragment)

Answer 18

DNA ligase

Question 19

Cellular process that uses specific enzymes to remove and replace incorrectly paired nucleotides

Answer 19

Mismatch repair

Question 20

An enzyme that cuts DNA or RNA either by removing one or a few bases or hydrolyzing the DNA or RNA completely into its component nucleotides

Answer 20

Nuclease

Question 21

A repair system that removes and then correctly replaces a damaged segment of DNA using the undamaged strand as a guide

Answer 21

Nucleotide Excision Repair

Question 22

Tandemly repetitive DNA at the end of a eukaryotic chromosome’s DNA molecule. These protect the organism’s genes from being eroded during successive rounds of replication.

Answer 22

Telomere

Question 23

Enzyme that catalyzes the lengthening of telomeres in eukaryotic germ cells

Answer 23

Telomerase

Question 24

Complex of DNA and proteins that makes up eukaryotic chromosomes. When a cell is not dividing, this exists in its dispersed form, as a mass of very long, thin fibers that are not visible with a light microscope.

Answer 24

Chromatin

Question 25

Eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed

Answer 25

Heterochromatin

Question 26

Less condensed form of eukaryotic chromatin that is available for transcription

Answer 26

Euchromatin