SB8??

in a natural population, ___________ genotype is the most common one.

Blank 1: wild or wild type Blank 2: type

CRISPR RNA

Guides an endonuclease to foreign DNA

A germ-line mutation is one that occurs in ______.

a sperm or egg cell

In an experiment, 1 million bacteria were plated and 10 were found to be mutant. What is the mutation frequency?

10-5

Identify the roles of the protein LSD1 in the repression of transcription by HOTAIR.

Binds to 3' end of HOTAIR Demethylates H3K4

What two proteins cleave the pre-miRNA in the nucleus?

Drosha DGCR8

TERC

Facilitates the binding of telomerase to the telomere

True or false: Deleterious mutations that cause the death of a cell are called nonsense mutations.

False

The ncRNA Hox transcript antisense intergenic RNA is also known as

HOTAIR

How does ionizing radiation cause mutations?

It forms free radicals that can introduce breaks into the DNA molecule.

In which of the following ways does 5-bromouracil cause a mutation?

It replaces the base thymine, and can base pair with guanine rather than adenine.

Which of these are trinucleotide repeat expansion disorders?

Myotonic muscular dystrophy Fragile X syndrome Huntington disease

Which of these are examples of mutagens?

Nitrogen mustard 2-Aminopurine Nitrous acid 5-Bromouracil

What type of mutations involve a change from a normal codon to a stop codon?

Nonsense mutations

PIWI-interacting RNA

Prevents the movement of transposable elements Prevents the movement of transposable elements

Select the molecules to which ncRNAs commonly bind.

Proteins mRNA Small molecules DNA

Scaffold Guide Ribozyme Blocker Decoy

Some ncRNAs contain binding sites for multiple molecules Some ncRNAs function to deliver a molecule to a specific site Some ncRNAs have catalytic function Some ncRNAs prevent cellular processes from occurring Some ncRNAs bind to other ncRNAs and sequester them

Identify the roles of the PCR2 complex in the repression of transcription by HOTAIR.

Trimethylates H3K27 Binds to 5' end of HOTAIR

CRISPR-Cas systems provide a defense against ______.

bacteriophages transposons plasmids

A mutation that enhances the survival and/or reproductive success of an individual is referred to as a(n) mutation.

beneficial

Physical mutagens include

both X-rays and UV light

Which of these bases is most readily deaminated?

cyt

During miRNA processing, a protein called ____ 5 helps to export the pre-miRNA from the nucleus.

exportin

An individual that is ______ for the sickle cell allele has a decreased chance of survival.

homozygous

Trinucleotide repeat expansions are repeated sequences of three nucleotide bases which ______.

increase generation after generation

Fill in the blanks to complete the sentence. An agent that can change DNA structure and cause mutations is known as a(n)

mutagens

An allele that has a DNA sequence different from that of the wild-type is called a(n) allele.

mutant

mutation is a missense mutation that has no detectable effect on protein function.

neutral

A(n) ______ mutation refers to a mutation in which just one base is changed within the DNA sequence.

point

Oxidative DNA damage refers to changes in DNA structure that are caused by ______.

reactive oxygen species

Mutations in body cells that do not go on to form gametes are known as ______ mutations.

somatic

Errors in DNA replication are examples of ______ mutations, while mutations caused by ultraviolet light are ______ mutations.

spontaneous ; induced

Which of the following base changes are transversion mutations?

A to C G to C A to T

During the interference phase of the CRISP-Cas defense system, each spacer within a ______ is complementary to one of the strands of the bacteriophage DNA.

crRNA

The removal of an amino group from a base is called

deamination, deaminization, or deaminating

Silent mutations are possible because the genetic code is ______.

degenerate

Sickle cell disease is caused by a ______ mutation in the gene for the ______ chain.

missense; β-globin

In the CRISPR-Cas defense system, what triggers the expression phase?

A subsequent bacteriophage infection

Which of the following base changes is a transition mutation?

A to G

Select the roles played by the ncRNA HOTAIR.

Alteration of chromatin structure Repression of gene transcription

If RISC directs the degradation of a bound mRNA, what protein cleaves the mRNA?

Argonaute

A mutation that occurs directly in a sperm or egg cell, or in one of their precursor cells, is referred to as a(n)

Blank 1: germ or germ line Blank 2: line

Alkylating agents covalently attach __ or ___ groups to DNA bases, and thus disrupt their normal base pairing properties.

Blank 1: methyl or CH3 Blank 2: ethyl, CH2CH3, or CH3CH2

A mutagen is a(n) ______.

agent that causes mutations

Alkylating agents cause mutations by ______.

disrupting the normal pairing between nucleotides within the DNA

Which ncRNA associates with proteins to direct the synthesis of certain polypeptides to the plasma membrane?

SRP RNA

The mutation rate is commonly expressed as the number of new mutations in a given ______.

gene per cell generation

Which type of RNA might originate in a virus?

siRNA

The base cytosine is deaminated to produce the base

uracil

The phenomenon in which a repeated sequence of three nucleotide bases increases in number generation after generation is called

Blank 1: trinucleotide Blank 2: repeat Blank 3: expansion

Which of these mutations changes a mutant allele back to a wild-type allele?

Reversion

Base analogs induce mutations by ______.

being incorporated instead of normal bases during DNA replication

A mutant allele is best defined as an allele that ______.

has a different DNA sequence from the wild-type

Photoreactivation is a repair mechanism that can ______ a thymine dimer in the ______ of light.

directly split; presence

MicroRNAs play a key role in regulating gene expression particularly ______.

during embryonic development in animals and plants

The addition or deletion of a number of bases that is not a multiple of 3 causes a(n) mutation.

frameshift

Which type of RNA is exogenous?

siRNA

Which changes can cause a frameshift mutation?

A base addition A base deletion

COLDAIR

Alters chromatin structure, repressing transcription Alters chromatin structure, repressing transcription

Fill in the blanks to complete the sentence. Changes to DNA structure caused by reactive oxygen species (ROS) are termed

Blank 1: oxidative Blank 2: DNA Blank 3: damage

A mutation is one that converts a mutant allele back to the wild-type form.

Blank 1: reverse, reversion, or reversal

Fill in the blanks to complete the sentence. A change of one base for another is described as a base mutation.

substitution or point

A deleterious mutation is best defined as one that decreases the chance of ______.

survival and reproduction

Fill in the blanks to complete the sentence. A mutation that results in a premature termination of the synthesis of a polypeptide is called a(n) mutation.

nonsense

MicroRNAs influence gene expression by ______.

inhibiting translation of mRNA

Nucleotide excision repair (NER) is found in ______.

both prokaryotes and eukaryotes

Mutations that remove an adenine or guanine from the DNA are known as ______.

depurination

The strand that is repaired in the mismatch repair system is ______.

the nonmethylated strand

The wild type genotype or phenotype is the one that is ______ found in nature.

typically

Thymine dimers are typically caused by ______.

ultraviolet light

A missense mutation in the β-globin gene is responsible for sickle cell disease. This mutation causes an altered polypeptide sequence where the sixth amino acid is changed from glutamic acid to ______.

valine

In an average human individual, naturally occurring double-strand breaks occur at a rate of ______ per cell per day.

10-100

Fill in the blanks to complete the sentence. A mutation that results in the death of an organism is known as a(n) mutation.

: lethal

Which of the following statements regarding somatic and germ-line mutations is true?

A germ-line mutation typically originates during meiosis whereas a somatic mutation typically originates during mitosis.

Which are examples of somatic mutations?

A mutation in an adult muscle cell A mutation in an embryonic kidney cell

Which enzyme can remove methyl or ethyl groups from guanines that have been subjected to mutagens such as nitrogen mustard?

Alkyltransferase

Fill in the blanks to complete the sentence. An immune type system in prokaryotes that protects against foreign invaders is called the

Blank 1: CRISPR Blank 2: Cas or Cas9

Certain compounds have a structure similar to normal DNA bases and so can be incorporated into daughter strands during DNA replication. These compounds are called base

Blank 1: analogs, analogues, or analog

Some errors affect individual nucleotides and do not distort the DNA double helix. These errors are removed primarily by a DNA repair system called BER, which stands for

Blank 1: base or base excision Blank 2: excision

The breakage of chromosomes is referred to as a(n)

Blank 1: double or double strand Blank 2: strand, stranded, double strand, or strands

Ionizing radiation produces chemically reactive molecules known as . These are mutagenic because they alter the structure of DNA.

Blank 1: free Blank 2: radicals

The two main mechanisms used to repair DNA double-strand breaks are recombination repair and end joining.

Blank 1: homologous Blank 2: nonhomologous or non-homologous

Fill in the blanks to complete the sentence. An individual that has one copy of the sickle cell allele and one copy of the wild-type allele has an increased level of resistance to the disease

Blank 1: malaria

A base substitution in DNA that ultimately leads to a change in the encoded amino acid is called a(n) mutation.

Blank 1: missense

Fill in the blanks to complete the sentence. The probability that a gene will be altered by a new mutation is referred to as the

Blank 1: mutation Blank 2: rate

'' RNA molecules that do not encode polypeptides are called

Blank 1: non, nc, or n Blank 2: coding, RNA, or c

Mutations can be caused in two main ways: (1) mutations are the result of natural biological or chemical processes; and (2) mutations are produced by environmental agents.

Blank 1: spontaneous Blank 2: induced

A change of one base for another is described as a base

Blank 1: substitution or point

Ultraviolet light causes the formation of crosslinked in DNA.

Blank 1: thymine, pyrimidine, or T Blank 2: dimers

'' A base substitution in which a purine and a pyrimidine are interchanged is called a(n)

Blank 1: transversion, transverse, transversions, transversive, or transversal

This child has the disease ____, which makes her more susceptible to skin cancer.

Blank 1: xeroderma or x Blank 2: pigmentosum or p

In trinucleotide repeat expansion disorders, when the expansion occurs in the coding sequence of the gene, the repeat sequence is usually ______.

CAG

During adaptation, what proteins in the CRISPR-Cas system are involved in recognizing and cleaving bacteriophage DNA into small pieces?

Cas2 Cas1

Which of the following are examples of base pair mismatches?

Cytosine on parent strand and Thymine on daughter strand Adenine on parent strand and Cytosine on daughter strand Cytosine on parent strand and Adenine on daughter strand

MutS MutL MutH MutU exonucl

Detects the mismatch Acts as a linker that helps loop the DNA Makes a cut in a nonmethylated strand Separates strands at the cleavage site Digests the nonmethylated strand

Which of the following is least likely to occur as a result of a double-strand break?

Duplications

True or false: During homologous recombination repair, the two broken ends of DNA are pieced back together.

False

True or false: The nucleotide excision repair system of DNA repair is unique to prokaryotes.

False

What can cause double-strand breaks (DSBs)?

Gamma rays X-rays Reactive oxygen species

What type of molecules does HOTAIR help guide to their target genes?

Histone-modifying complexes

If the proofreading ability of a DNA polymerase fails, which of the following DNA repair systems is most likely to detect the resulting mutations and fix them?

Mismatch repair system

In the mismatch repair system, select the two Mut proteins that form a complex, activating a third Mut protein, which is already bound to a hemimethylated DNA site.

MutS/MutL ; MutH

Which of the following enzymes participate in the base excision repair system of humans?

N-glycosylase Flap endonuclease AP endonuclease

What outcomes can occur once RISC binds to an mRNA?

RISC may direct the degradation of the mRNA. The RISC-mRNA complex may remain in a P-body. RISC may inhibit translation without degrading the mRNA.

What is the function of the ncRNA HOTAIR?

Scaffold

Select functions commonly carried out by ncRNAs.

Scaffold Decoy Guide Alteration of protein function or stability Blocker Ribozyme

In the mismatch repair system, how is the newly-made daughter strand distinguished from the parental strand?

The parental strand is methylated, while the daughter strand is not.

In the nucleotide excision repair (NER) system, select the complex that recognizes damaged DNA, followed by the proteins that act to remove the damaged DNA.

UvrA/UvrB complex; UvrC (endonuclease) and UvrD (helicase)

Which of the following human diseases is associated with a high predisposition to skin cancer because of an inability to repair UV-induced lesions?

Xeroderma pigmentosum

Base excision repair (BER) is the main system used in the repair of ______.

abnormal bases

'' Consider a DNA that has been exposed to the alkylating agent nitrogen mustard. The protein that can remove the ethyl and methyl groups from the guanine bases is called

alkyltransferase

5-bromouracil is a base ______ that changes a(n) ______.

analog; AT base pair to a GC base pair

In a neutral mutation, a negatively-charged amino acid is substituted for ______.

another negatively-charged amino acid

The covalent bond between deoxyribose and a purine base is rather unstable and can undergo a spontaneous reaction with water. The breaking of the bond releases the base, and leaves a(n) site in the DNA.

apurinic

During the normal course of DNA replication, the addition of a nucleotide that does not obey the AT/GC rule of base pairing creates a ______.

base pair mismatch

Nucleotide excision repair (NER) is the main system used in the repair of ______.

bulky, helix distorting lesions

A silent mutation is a mutation that results in no ______.

change to the amino acid sequence of the polypeptide

A mutant Drosophila fly can land on the side of a fly bottle when the bottle is incubated at 20-23o C but not at 24-27o C. This is an example of a(n)

conditional

Mutations that affect the phenotype only under certain circumstances are called ______ mutations.

conditional

The breakage of chromosomes is referred to as a(n) - break.

double strand

The number of mutant genes divided by the total number of copies of that gene within a population is a value known as the gene's mutation

frequency

Proteins associated with trinucleotide repeat expansion disorders typically contain long tracts of the amino acid

glutamine

During DNA replication, a base that does not obey the normal AT/GC base pairing rule is added. This type of mutation is most likely corrected by the

mismatch repair sys

A heritable change in the genetic material is called a(n) ______.

mutation

Some errors create bulky distortions of the double helix. These errors are removed primarily by a DNA repair system called NER, which stands for

nucleotide excision repair

Fill in the blanks to complete the sentence. The process by which thymine dimers are directly repaired with the help of light is called

photoreactivation

Place the events in the repression of transcription by HOTAIR in order from first to last. Instructions

sc

A mutation that does not change the amino acid sequence of a polypeptide is known as a(n)

silent

Which of the following bases is produced by the deamination of 5-methylcytosine?

thy

is a type of base substitution that involves a change of a pyrimidine to another pyrimidine, or a purine to another purine.

transition or transitions