Bio Exam 4: Chapter 20

Gel electrophoresis

A technique that uses a gel made of a polymer as a molecular sieve to separate out nucleic acids by size

B

The reason for using Taq polymerase for PCR is that _____. a) only minute amounts are needed for each cycle of PCR b) it is heat stable and can withstand the heating step of PCR c) it has regions that are complementary to the primers d) it binds more readily than other polymerases to the primers

Denaturation, annealing, and extension

Three-step cycle of PCR:

95 to 55 to 72

What is the temperature change in PCR?

Cloning vector

A DNA molecule that can carry foreign DNA into a host cell and replicate there

Electroporation

A brief electrical pulse is applied to a solution containing cells creating temporary holes in their plasma membranes, through which DNA can enter

Expression vector

A cloning vector that contains a highly active bacterial promoter just upstream of a restriction site where the eukaryotic gene can be inserted in the correct reading frame

complementary DNA

A form of the gene that includes only the exons

Recombinant DNA

A molecule containing DNA from two different sources (usually a plasmid and foreign DNA)

Stem cell

A relatively un-specialized cell that both reproduce itself indefinitely and, under appropriate conditions, differentiate into specialized cells of 1 or more types

Single nucleotide polymorphism

A single base-pair site where variation is found in at least 1% of the population

Polymerase chain reaction (PCR)

A technique that isolates a gene of interest and obtains many copies of the desired gene

DNA ligase

An enzyme that seals the bonds between restriction fragments

GMO

An organism that has acquired by artificial means 1 or more genes from another species or multiple other species

Transgenic

Animal that has a gene from another animal introduced to it

DNA microarray assays

Consists of tiny amounts of a large number of single-stranded DNA fragments representing different genes fixed to a glass slide in a tightly spaced grid

Genetic markers

DNA sequences that vary in the population

Restriction enzymes (restriction endonucleases)

Enzymes that protect the bacterial cell by cutting up foreign DNA from other organisms or phages

DNA sequencing

Exploiting the principle of complementary base pairing to determine the complete nucleotide sequence of a DNA molecule

DNA isolation

First step for making cells with recombinant plasmids

D

Gel electrophoresis separates DNA fragments on the basis of what characteristic? a) mutations b) charge c) sequence d) length e) restriction sites

Gene amplification, protein production

Gene cloning is useful for two basic purposes: _________ & ____________________

negative, positive

In gel electrophoresis DNA molecules migrate from _____ to _____ ends of the gel.

Genetic profile

Individual's unique set of genetic markers

Genome-wide association studies

Large-scale analysis that do not require complete sequencing of all genomes in the two groups

Sequencing by synthesis

Method of identifying the sequence of a segment of DNA by using electronic monitors to identify which of four nucleotides is added during synthesis of a complementary strand

RNA interference method

Method that uses synthetic double-stranded RNA molecules matching the sequence double-stranded RNA molecules matching the sequence of a particular gene to trigger breakdown of the gene's messenger RNA or to block its translation

in vitro

Outside of the cell; in a test tube

Extension

Part of PCR where DNA polymerase adds nucleotides to the 3' end of each primer

Annealing

Part of PCR where the DNA is cooled to allow primers to form hydrogen bonds with ends of target sequence

Denaturation

Part of PCR where the DNA is heated briefly to separate the DNA strands

Restriction site

Particular short DNA sequence where a specific restriction enzyme makes specific cuts

DNA cloning

Preparing well-defined segments of DNA in multiple identical copies

Short tandem repeats

Repeated units of two- to five- nucleotide sequences in specific regions of the genome; allows for genetic markers

specific

Restriction enzymes are very _________

Restriction enzymes added

Second step for making cells with recombinant plasmids

Sticky end

Single-stranded end extension that is left after a restriction enzyme cuts at a restriction site; can form hydrogen bonds with a complementary piece

Plasmids

Small, circular DNA molecules that are replicated separately from the bacterial chromosome

DNA isolation, Restriction enzymes added, Mix & ligase added, recombinants produced, recombinants introduced (into bacterial cells), plate bacteria (onto agar with ampicillin in media), bacterial growth

Steps required to produce cells carrying recombinant plasmids

Gene inserted (in plasmid), plasmid inserted (into bacterial cell), growth (of bacterial cell), product (used in research or industry)

Steps to gene cloning

In vitro mutagenesis

Technique in which specific mutations are introduced into a cloned gene and the mutated gene is returned to a cell to disable the normal cellular copies of the same gene

In situ hybridization

Technique that allows one to see the mRNA in place and in the intact organism

DNA technology

Techniques for sequencing and manipulating DNA

Nucleic acid hybrization

The base pairing of one strand of a nucleic acid to the complementary sequence on a stand from another nucleic acid molecule

Nucleic acid probe

The complementary molecule, a short, single-stranded nucleic acid that can be either RNA or DNA

Genetic engineering

The direct manipulation of genes for practical purposes

DNA ligase

The enzyme that catalyzes the formation of covalent bonds that close up the sugar-phosphate backbones of DNA strands

Gene therapy

The introduction of genes into an afflicted individual for therapeutic purposes

Biotechnology

The manipulation of organisms or their components to make useful products

sticky ends

The most useful restriction enzymes cut DNA in a way to produce ________

Pluripotent

The potential to develop into many different cell types

Totipotent

The potential to give rise to all the specialized cell types of the organism

Gene cloning

The production of multiple copies of a single gene

Restriction fragments

The products of restriction enzymes making cuts at certain restriction sites

palindrome

The same forwards and backwards

palindromes

The sequences that restriction enzymes target are ___________

A

The sticky end of the DNA restriction fragment shown here will pair with a DNA restriction fragment with a DNA sequence of ____. TGCAGAATTC CTTAAG A) -ACGT B) -AAAA C) ACGU D) -GTAC

A

The sticky end of the DNA restriction fragment shown here will pair with a DNA restriction fragment with the sticky end _____. TGCAGAATTC CTTAAG a) -ACGT b) -AAAA c) -ACGU d) -GTAC e) -TGCA

A

The unpaired nucleotides produced by the action of restriction enzymes are referred to as _____. a) sticky ends b) base sequences c) single strands d) restriction fragments e) ligases

Reverse transcriptase PCR

Turns sets of mRNAs into double-stranded DNAs

template DNA, DNA polymerase, nucleotides, primer

What is needed for PCR?

D

What is the enzymatic function of restriction enzymes? a) to repair breaks in sugar-phosphate backbones b) to join nucleotides during replication c) to join nucleotides during transcription d) to cleave nucleic acids at specific sites e) to add new nucleotides to the growing strand of DNA

Taq DNA polymerase

What is the special DNA polymerase used in PCR?

heat

What is used to denature the DNA during PCR?

D

Which of the following is in the correct order for one cycle of polymerase chain reaction (PCR)? a) Extend primers; anneal primers; denature DNA. b) Denature DNA; add fresh enzyme; anneal primers; add dNTPs; extend primers. c) Anneal primers; denature DNA; extend primers. d) Denature DNA; anneal primers; extend primers.

B

Which of the following sequences could be cut by a restriction enzyme a) AATTCC & TTAAGG b) GTGCAC & GTGCAC c) ATC & TAG d) TTTGGG & AAACCC