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

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

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

Binds to 3' end of HOTAIR Demethylates H3K4

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

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

Blank 1: free Blank 2: radicals

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

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

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

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

change to the amino acid sequence of the polypeptide

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

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

silent

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

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

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

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

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

Blank 1: missense

'' RNA molecules that do not encode polypeptides are called

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

A mutagen is a(n) ______.

agent that causes mutations

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

another negatively-charged amino acid

Alkylating agents cause mutations by ______.

disrupting the normal pairing between nucleotides within the DNA

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

sc

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

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

typically

Thymine dimers are typically caused by ______.

ultraviolet light

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.

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

SRP RNA

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

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

analog; AT base pair to a GC base pair

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

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

gene per cell generation

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

glutamine

Which type of RNA might originate in a virus?

siRNA

The base cytosine is deaminated to produce the base

uracil

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

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

thy

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

depurination

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

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

Histone-modifying complexes

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

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

mutation

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