DNA and Bacterial Chromosomes Overview

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Questions and Answers

Match the following types of DNA sequences with their characteristics:

Unique sequences = Found once or a few times in the genome Moderately repetitive sequences = Found a few hundred to a few thousand times Highly repetitive sequences = Found tens of thousands to millions of times Transposable elements = Short segments of DNA that can move within the genome

Match the following examples with their classifications:

Genes for rRNA = Moderately repetitive sequences Alu family = Highly repetitive sequences AATAT = Highly repetitive sequences Protein coding genes = Unique sequences

Match the following terms with their definitions:

Transposition = Process in which a DNA segment is inserted into a new location Genome complexity = Number of times a particular sequence appears in the genome Centromeric regions = Common location for highly repetitive sequences Introns = Non-coding DNA found within unique sequences

Match the following characteristics with the respective DNA sequence type:

Highly repetitive sequences = Function is not well understood Moderately repetitive sequences = Includes transposable elements Unique sequences = Make up roughly 41% of the human genome Transposable elements = Can move to new locations in the genome Signup and view all the answers

Match the following sequence characteristics with their respective examples:

AATATAT in Drosophila = Highly repetitive sequences Protein coding genes = Unique or non-repetitive sequences Genes for rRNA = Moderately repetitive sequences Alu family in humans = Highly repetitive sequences Signup and view all the answers

Match the following terms with their correct descriptions regarding genetic material:

Genome = All the genetic material of an organism Nucleoid = Region of the cell where bacterial chromosome is found Intergenic regions = Nontranscribed DNA segments between genes Bacterial chromosome = Usually a single circular molecule Signup and view all the answers

Match the following functions of genetic material with their purposes:

Synthesis of RNA = Production of RNA from DNA Replication of chromosomes = Duplication of genetic material Gene regulation = Control of gene expression Chromosome compaction = Fitting DNA within the cell Signup and view all the answers

Match the following bacterial species with their chromosome lengths:

Escherichia coli = ~ 4.6 million base pairs Haemophilus influenzae = ~ 1.8 million base pairs Bacillus subtilis = ~ 4.2 million base pairs Streptococcus pneumonie = ~ 2.0 million base pairs Signup and view all the answers

Match the following components with their roles in bacterial DNA structure:

Microdomains = Loops extending from the chromosome core Central core = Main structural region of bacterial DNA Origin of replication = Initiation site for DNA replication Cytoplasm = Medium surrounding the nucleoid Signup and view all the answers

Match the following types of genomes with their associated organisms:

Nuclear genome = Eukaryotes Mitochondrial genome = Animals and plants Chloroplast genome = Plants Bacterial genome = Prokaryotes Signup and view all the answers

Match the following DNA sequences with their related functions:

Protein-encoding genes = Majority of bacterial DNA Repetitive sequences = Roles in DNA folding and regulation Structural genes = Define traits and functions of the cell Noncoding DNA = Segments that do not encode proteins Signup and view all the answers

Match the following descriptions of bacterial chromosome characteristics:

Compact structure = 1000-fold compaction in the cell Circular shape = Distinctive feature of bacterial chromosomes Length variability = Few million bps in typical bacteria Direct cytoplasmic contact = Nucleoid is not membrane-bound Signup and view all the answers

Match the following elements of bacterial genetics with their characteristics:

Genome complexity = Represents full genetic potential Gene density = High in bacterial chromosomes Chromosome number = Typically one in bacteria Genetic recombination = Involves exchange of DNA segments Signup and view all the answers

Match the following supercoiling effects with their outcomes:

Negative supercoiling = Compacts the chromosome Positive supercoiling = Creates tension causing DNA strand separation Supercoiling control = Influenced by DNA gyrase and topoisomerase I Topoisomerase I = Relaxes negative supercoils Signup and view all the answers

Match the following enzymes with their functions:

DNA gyrase = Creates negative supercoils using ATP Topoisomerase I = Relaxes negative supercoils Ciprofloxacin = Inhibits bacterial topoisomerases Coumarins = Another class of topoisomerase inhibitors Signup and view all the answers

Match the following components of eukaryotic chromosomes with their roles:

Origin of replication = Site where replication starts Centromere = Role in chromosome segregation Kinetochore = Links centromere to spindle apparatus Telomere = Prevents chromosome translocations Signup and view all the answers

Match the following terms related to Transposable Elements (TEs) with their definitions:

Transposons = TEs that move by a 'cut and paste' mechanism. Retrotransposons = TEs that move via retrotranscription. Flanking direct repeats = Sequences adjacent to the inserted TE. Inverted repeats = Palindromic sequences at the ends of TEs. Signup and view all the answers

Match the following types of genes with their characteristics:

Eukaryotic genes in yeast = Relatively small with few introns Complex eukaryotic genes = Long with many introns Intron lengths = Can range from less than 100 to over 10,000 bp Gene quantity = Hundreds to thousands per chromosome Signup and view all the answers

Match the following facts about eukaryotic genomes:

Genome size variation = Not necessarily related to complexity Salamander genome sizes = Two-fold difference in closely related species Repetitive DNA sequences = Do not encode proteins Genome compositions = Influenced by number of genes and repetitive sequences Signup and view all the answers

Match the following types of TEs with their characteristics:

LTR Retrotransposons = Contain long terminal repeats and reverse transcriptase. Non-LTR Retrotransposons = Do not contain long terminal repeats. Autonomous TEs = Complete elements that can transpose independently. Nonautonomous TEs = Incomplete elements that rely on autonomous TEs for movement. Signup and view all the answers

Match the following enzyme actions with their roles in transposition:

Transposase = Enzyme that catalyzes the removal and reinsertion of TEs. Reverse transcriptase = Enzyme that synthesizes DNA from RNA. Integrase = Enzyme that helps insert TEs into new DNA sites. Endonuclease = Enzyme that cleaves DNA strands during transposition. Signup and view all the answers

Match the following definitions with the correct terms:

Microdomain organization = Formed by NAPs Negative supercoil occurrence = One per 40 turns of the double helix Function of helicases = Unwind DNA for replication Role of supercoiling = Enhances replication and transcription Signup and view all the answers

Match the following scientists or concepts with their contributions or definitions:

Barbara McClintock = First to identify transposable elements in corn. Jumping genes = Common term used to describe transposable elements. Antibiotic resistance gene = Example of a gene carried by simple transposons. 7SL RNA gene = Origin of the Alu sequence in humans. Signup and view all the answers

Match the classes of drugs with their descriptions:

Quinolones = Inhibit bacterial topoisomerases Coumarins = Target bacterial gyrase Ciprofloxacin = Used in anthrax treatment Topoisomerase inhibitors = Do not affect eukaryotic topoisomerases Signup and view all the answers

Match the following components with their function in transposable elements:

Transposase gene = Gene necessary for transposition. Long terminal repeats = Structural features of LTR retrotransposons. Inverted repeats = Sequences that flank transposons. Direct repeats = Repetitive sequences adjacent to TEs post-insertion. Signup and view all the answers

Match the following components of bacterial chromosomes:

Microdomains = Organized into macrodomains NAPs = Form DNA bridges Chromosomal DNA in bacteria = Primarily negatively supercoiled Supercoiling tension = Facilitates strand separation Signup and view all the answers

Match the following types of transposition with their features:

Simple transposition = Involves a 'cut and paste' mechanism. Retrotransposition = Involves transcribing TE to RNA before DNA synthesis. TE increase = Occurs during retrotransposition. Excision = Removal of the TE from its original location. Signup and view all the answers

Match the following plants with their respective transposable elements:

Corn = Complete Ac element. Ds element = Nonautonomous element needing transposase. 7SL RNA gene = Source for human Alu sequences. Bacteria = Example of a diverse group harboring TEs. Signup and view all the answers

Match the following definitions with their correct terms regarding TE characteristics:

Complete TEs = Also known as autonomous TEs. Incomplete TEs = Referred to as nonautonomous TEs. Transcription = The process involved in retrotransposition. Genome = The overall structure where TEs can move. Signup and view all the answers

Match the following types of transposable elements with their characteristics:

Transposon = Uses a DNA template for transposition Retrotransposon = Uses an RNA intermediate for transposition Insertion Element = Commonly found in multiple copies Antibiotic Resistance Transposon = Carries genes for antibiotic resistance Signup and view all the answers

Match the following organisms with their corresponding transposable elements:

E. coli = IS1 S. cerevisiae = Ty elements Drosophila = P elements Humans = Alu Signup and view all the answers

Match the following functions with their respective enzymes involved in retroelement transposition:

Transcription = Produces RNA from retrotransposon Reverse Transcriptase = Synthesizes dsDNA from RNA Integrase = Catalyzes insertion of the TE into the genome RNA Template = Serves as a blueprint for DNA synthesis Signup and view all the answers

Match the following transposable elements with their approximate length:

IS1 = $768$ bp Tn10 = $9300$ bp Alu = $300$ bp L1 = $6500$ bp Signup and view all the answers

Match the following characteristics with the corresponding type of transposable element:

Ac/Ds = Found in corn and other plants P elements = Absent from M strains of Drosophila Ty elements = About 35 copies per genome in S. cerevisiae L1 = About 500,000 copies in the human genome Signup and view all the answers

Match the following processes with their descriptions relevant to transposable elements:

Transposition = Movement of transposable elements within the genome Replication = Transposable elements can replicate around this time Mutation = Transposable elements can influence genetic variability Proliferation = Rapid increase in the number of transposable elements Signup and view all the answers

Match these transposable elements to the main type they belong to:

IS1 = Transposon Ty elements = Retrotransposon L1 = Retrotransposon Ac = Transposon Signup and view all the answers

Match the following descriptions of transposable elements with their examples:

An insertion element usually in E. coli = IS1 Known for providing antibiotic resistance = Tn10 Found in the human genome at high copy numbers = Alu Commonly found in corn = Ac Signup and view all the answers

Match the species with their corresponding percentage of the total genome composed of transposable elements (TEs):

Frog (Xenopus laevis) = 77% Corn (Zea mays) = 60% Human (Homo sapiens) = 45% Fruit fly (Drosophila melanogaster) = 20% Signup and view all the answers

Match the negative effects of transposons with their corresponding causes:

Chromosome breakage = Excision of a TE Gene inactivation = Insertion of a TE into a gene Mutation = Incorrect excision of TEs Gene duplications = Insertion of a gene into a transposon Signup and view all the answers

Match the consequence of transposition with its description:

Chromosomal rearrangements = Homologous recombination between TEs Alteration in gene regulation = Transposition next to regulatory sequences Alteration in exon content = Insertion of exons into a gene Hybrid dysgenesis = Drosophila crosses with P elements Signup and view all the answers

Match the hypothesis regarding the biological significance of transposons:

Selfish DNA hypothesis = Exist because they can Advantage hypothesis = Offer beneficial functions Insertion of exons = Exon shuffling Antibiotic-resistance genes = In bacteria Signup and view all the answers

Match the organisms with their corresponding TEs abundance:

Corn (Zea mays) = 60% Human (Homo sapiens) = 45% Nematode (Caenorhabditis elegans) = 12% Bacterium (Escherichia coli) = 0.3% Signup and view all the answers

Match the factor that can stimulate transposon activity:

Radiation = Can cause transposition Mutagens = Increase mutations Hormones = Influence growth Temperature = Affect genetic stability Signup and view all the answers

Match the gene effects caused by transposons:

Exon shuffling = New gene functions Gene inactivation = Loss of function Mutation = Change in sequence Chromosomal abnormalities = Structural changes Signup and view all the answers

Match the term with its definition related to transposons:

Transposase = Enzyme facilitating transposition Nonautonomous TEs = Lack functional transposase gene Autonomous TEs = Can move independently TEs = Transposable elements Signup and view all the answers

Match the statement with the corresponding concept of transposons:

Can proliferate like parasites = Selfish DNA hypothesis Deleterious transpositions eliminated = Advantage hypothesis Insertion into coding region = New functions via exons Impact on chromosome structure = Harmful outcomes Signup and view all the answers

Flashcards

Bacterial Chromosome

A circular DNA molecule containing the genetic material of a bacterium, typically a few million base pairs long.

Bacterial Genome

All the genetic material (DNA) in a bacterium.