Exam 2 Chapter 10

Eukaryotic

A chromosome that is linear, millions of base pairs long, has a centromere, two telomeres, and multiple origins of replication is from what type of cell? Multiple choice question. Prokaryotic Eukaryotic

territory

A discrete region of the nucleus where a chromosome is located is known as a chromosome .......

intron

A non-coding sequence of DNA that is found within a protein coding gene is called a(n) .......

transposition

A process that leads to the accumulation of repetitive sequences in the genome through insertion of short DNA segments in new locations is called ......

heterochromatin

A region of a chromosome with highly compacted chromatin is called ______. Multiple choice question. heterochromatin euchromatin

simple transposition

A situation where a transposable element is removed from its original site and transferred to a new target site is called ______. Multiple choice question. retrotransposition homologous recombination simple transposition viral insertion

thousands,

A typical eukaryotic gene ranges in size from several thousand to tens of ....... of base pairs.

macrodomains

After the E. coli chromosome has been compacted by the formation of microdomains, groups of 80-100 adjacent microdomains are further organized into ______. Multiple choice question. superdomains macrodomains interspersed domains repetitive domains

transposase

An insertion element is a transposable element typically containing direct repeats, inverted repeats and a coding region for an enzyme called .......

Several thousand to tens of thousands of base pairs

Approximately how large is a typical eukaryotic gene? Multiple choice question. Several hundreds of thousands to several million base pairs Several hundreds to several thousands of base pairs Several tens of thousands to several hundreds of thousands of base pairs Several thousand to tens of thousands of base pairs

Blank 1: DNA Blank 2: protein

Chromatin is the complex of ....... and. ........ found within eukaryotic chromosomes.

negative

DNA gyrase, or topoisomerase II, introduces ______ supercoils into DNA. Multiple choice question. negative positive

at both ends of all transposable elements

Direct repeats, also called target-site duplications, are found ______. Multiple choice question. only at the ends of transposable elements in bacteria at both ends of all transposable elements at both ends of transposons but are missing from retrotransposons only at the 5' end of a transposable element

supercoiling

Due to the fact that the two strands of DNA in a double helix are wound around one another, twisting forces applied to the DNA double helix result in the introduction of additional coils, a process known as DNA .......

the insertion of exons from one gene into another gene to produce a different gene sequence

Exon shuffling is ______.

Transposable elements may promote recombination. Transposable elements may cause the insertion of exons from one gene into another gene.

How could the presence of transposable elements within a cell increase genetic diversity?

It brings chromatin loop domains together and holds them in place

How does condensin compact euchromatin into heterochromatin to form metaphase chromosome structure?

Two sets of 23

How many chromosomes and sets of chromosomes are found in a normal human somatic cell? Multiple choice question. One set of 23 Two sets of 23 One set of 46 Two sets of 46

more

If we compared the amount of DNA in the genome of a eukaryote to the amount of DNA in a bacterium would generally find that there is ______ DNA in the genome of a eukaryote than in the genome of a bacterium. This means there is likely a greater number of genes in the genome of the eukaryote. Multiple choice question. less more

A bacterium

If you knew that a chromosome had a single origin of replication, from what kind of cell would you predict it came? Multiple choice question. A bacterium A eukaryotic cell

A eukaryotic cell

If you knew that a chromosome had multiple origins of replication, what kind of cell would you predict it came from?

bacterium

If you were told that a chromosome was about a million base pairs long, had a single origin of replication, was circular, and contained about a thousand genes, then you would be confident that the chromosome was from a .......

DNA in the linker regions

In Noll's experiment, which portion of nucleosome structure was expected to be more accessible to the DNase I enzyme? Multiple choice question. The histone octomer DNA in the linker regions DNA associated with the core histones Histone H1

nucleoid

In a bacterium, the region of the cytoplasm where the compacted chromosome is located is called the .......

Blank 1: negative Blank 2: positive

In a nucleosome, the DNA can associate with the histone proteins because the DNA has a ........ charge and the histone proteins have a ......charge.

The basic histone proteins are attracted to the phosphate groups along the DNA backbone.

In a nucleosome, what is the nature of the chemical attraction between the histone proteins and the DNA?

size,

In many cases, variations in the ........ of eukaryotic genomes are not related to the complexity of the species.

metaphase

In preparation for cell division, each chromosome assumes a highly compacted form called a(n) ....... chromosome.

Number of times a particular sequence appears in the genome

In respect to eukaryotic genomes, what is sequence complexity? Multiple choice question. Number of introns per gene Number of exons per gene The variation seen between genomes of related species Number of times a particular sequence appears in the genome The number of times that the four bases are used per gene

macrodomains

In the E. coli chromosome, groups of 80-100 microdomains are further organized into ..........

Black arrows: core histones; Red arrow: DNA

In the diagram of the nucleosome, to what do the black and red arrows point? Multiple choice question. Black arrows: DNA; Red arrow: core histones Black arrows: histone H1; Red arrow: DNA Black arrows: core histones; Red arrow: DNA

Blank 1: histone Blank 2: DNA

In the diagram, the black arrows point at ....... proteins, and the pink arrow points at a strand of .......

unstable locations on corn chromosomes that led to Barbara McClintock's proposal of the action of transposable elements

Mutable sites are ______.

H1

One of the steps in chromosome compaction involves the packaging and compaction of nucleosomes into the 30 nm fiber. Such compaction and packaging is probably regulated by which histone protein? Multiple choice question. H2a H2b H4 H3 H1

outside

Prior to M phase condensin is located ______ the nucleus. Multiple choice question. inside outside

Blank 1: nucleus Blank 2: chromosomes

Prior to M phase, condensin is found outside the ...... ; however, as M phase begins condensin is observed to coat the ....... as euchromatin is condensed to heterochromatin

exon shuffling

Producing a new gene sequence by introducing exons from one gene into another gene is called ______. Multiple choice question. exon shuffling gene rearrangement intron excision recombination

nonrepetitive

Protein-encoding genes are typically ______ sequences. Multiple choice question. moderately repetitive nonrepetitive highly repetitive

transposition

Repetitive sequences can arise in the genome through a process called ______ where short segments of DNA are inserted into new locations. Multiple choice question. transcription replication transposition translation

facilitating the folding of the 30-nm fiber into loop domains

SMC proteins and CCCTC binding factors are responsible for ______.

Coding regions for retroviral-related proteins needed for transposition Long terminal repeats at both ends

Select all that apply Which types of DNA sequences are characteristic of LTR retrotransposons? Multiple select question. Short inverted repeats at both ends Coding regions for retroviral-related proteins needed for transposition Long terminal repeats at both ends Genes for antibiotic resistance

Blank 1: nonrepetitive Blank 2: unique

Sequences found only once or a few times within a genome, including protein-encoding genes, are called ....... or .......

exons

Sequences in an mRNA molecule that remain after splicing and which code for polypeptide are called .......

cohesin

The SMC protein that promotes the binding of sister chromatids is called ......

telomeres

The chromosomal structures that prevent both chromosomal shortening and chromosomal rearrangements are called .......

genome

The entire complement of genetic material in an organism is known as the ..........

supercoils

The enzyme DNA gyrase introduces negative ....... into DNA.

complexity

The number of times a particular base sequence appears in a genome is referred to as sequence .......

condensin

The process of forming metaphase chromosomes by pulling chromatin loops close together and holding them in place is facilitated by the ....... protein.

selfish

The proposal that transposable elements act as parasites, using the cell's resources to increase in number but providing no selective advantage to the cell is called the ______ DNA hypothesis. Multiple choice question. harmful selfish neutral non-advantageous

transposable elements use a cell's resources to multiply but provide no selective advantage to the cell

The selfish DNA hypothesis suggests that ______.

Blank 1: cohesin Blank 2: condensin

There are two proteins that drive the condensation (compaction) of interphase chromosomes into metaphase chromosomes. Those two proteins are called ...... and ........

Blank 1: linker Blank 2: histones

To demonstrate the amount of DNA associated with each nucleosome, Noll digested chromatin with DNase I. He reasoned that the ............ region would be more accessible to the enzyme than the region tightly bound to the core. ..........

long DNA sequences that are moderately or highly repeated in the eukaryotic genome

Transposable elements called LINEs are ______.

removal of a transposable element from its original location and the insertion of the element at a new location

Transposase is an enzyme that catalyzes the ______.

False

True or false: There is a close relationship between the complexity of a eukaryotic organism and genome size. True false question.TrueFalse

Telomeres, centromeres, and origins of replication

What DNA sequences are required for the replication and segregation of eukaryotic chromosomes? Multiple choice question. Telomeres and origins of replication only Telomeres and centromeres only Centromeres and origins of replication only Telomeres, centromeres, and origins of replication Telomeres, centromeres, origins of replication, and exons

Transposable elements may promote recombination, leading to increased genetic diversity. Through exon shuffling, new gene combinations can be produced. Transposable elements carrying antibiotic-resistance genes assist with bacterial cell survival. Transposable elements may play a role in gene regulation.

What are possible advantages to having transposable elements within a cell?

Linear Present in one or more sets Found in nucleus

What are the defining features of eukaryotic chromosomes? Multiple select question. Linear Circular Found in nucleoid Present in one or more sets Only one copy ever present Found in nucleus

Prevention of chromosomal shortening Prevention of chromosomal rearrangements

What are the functions of telomeres? Multiple select question. Attachment of the chromosome to the mitotic spindle Prevention of chromosomal shortening Prevention of chromosomal rearrangements Prevention of pairing of homologous chromosomes during mitosis Prevention of recombination during mitosis

Chromosomes are about a few million base pairs long Chromosomes generally have thousands of different genes Chromosomes have a single origin of replication Chromosomes are generally circular

What are the key features of bacterial chromosome organization and structure?

Possess centromeres Tens of millions to hundreds of millions of base pairs long Occur in sets (e.g. diploid) Linear Multiple origins of replication Possess telomeres

What are the key features of eukaryotic chromosomes?

Formation of the 30-nm fiber Wrapping DNA around histone octamers Condensing into metaphase chromosomes Formation of loop domains

What are the levels of eukaryotic chromosome compaction?

Cohesin Condensin

What are the names of the two proteins involved in the formation of metaphase chromosomes? Multiple select question. Loop attachment proteins Cohesin Histone H2A Condensin Histone H4

A discrete region in the nucleus where a chromosome is located

What is a chromosome territory?

A region in a bacterial cell where the compacted chromosome is located

What is a nucleoid? Multiple choice question. The membrane bound organelle where the chromosomes are located A region in the cytoplasm where ribosomes accumulate to concentrate protein synthesis A small cytoplasmic region where nutrients are concentrated A region in a bacterial cell where the compacted chromosome is located A part of the cell membrane where the bacterial chromosome is attached

A non-coding sequence of DNA found within a gene

What is an intron? Multiple choice question. A non-coding sequence of DNA to which kinetochore proteins bind A sequence of DNA that protects the ends of eukaryotic chromosomes A non-coding sequence of DNA found within a gene A coding sequence of DNA that produces tRNA molecules

The tightly compacted regions of chromosomes

What is heterochromatin?

To promote the binding of sister chromatids

What is the function of cohesin?

Exons

What is the name for the regions of an RNA molecule that code for protein and remain after splicing? Multiple choice question. Exons Telomeres Introns Promoters Cistrons

LINEs

What is the name for transposable elements consisting of long DNA sequences that are moderately or highly repeated in eukaryotic cells? Multiple choice question. SINEs insertion sequences P elements LINEs Alu elements

Chromatin

What is the name of the complex of DNA and protein found within eukaryotic chromosomes? Multiple choice question. Chromatin Nuclear cytoplasm Nuclear matrix Stroma

Packaging and compaction of nucleosomes

What is the role of histone H1? Multiple choice question. Translational repression Packaging and compaction of nucleosomes Decondensation of heterochromatin Activation of transcription Repression of transcription

A eukaryotic cell

What kind of cell would contain linear chromosomes found in sets and located in a nucleus? Multiple choice question. A bacterial cell A prokaryotic cell A eukaryotic cell A virus

The genome

What name is given to the entire complement of genetic material in an organism? Multiple choice question. The proteome The genome Transcriptome Phenotype Genotype

Supercoils

What would you call the additional coils that form when a double-helix of DNA is subject to twisting forces? Multiple choice question. Solenoids Hypercoils Nucleoids Z-DNA coils Supercoils

less; genes

When comparing bacterial and eukaryotic genomes, the bacterial genome is generally smaller and, therefore, contains ______ DNA and fewer ______. Multiple choice question. less; genes more; chromosomes more; genes

DNA sequences of a few hundred base pairs that are found dispersed throughout the eukaryotic genome

Which best describes transposable elements called SINEs?

transposase

Which enzyme catalyzes the excision of a DNA transposable element from its original site and the element's insertion at a new site? Multiple choice question. excisionase integrase endonuclease transposase reverse transcriptase

reverse transcriptase

Which enzyme produces a double-stranded DNA molecule from an RNA transcript of a retrotransposon? Multiple choice question. RNA polymersase integrase endonuclease DNA polymerase reverse transcriptase

integrase

Which enzyme recognizes the long terminal repeats at the ends of a DNA copy of an LTR-retrotransposon and catalyzes the insertion of the element into its new location? Multiple choice question. reverse transcriptase endonuclease DNA polymerase integrase

Direct repeats

Which feature is found at both ends of all transposable elements? Multiple choice question. Inverted repeats Direct repeats Viral DNA sequences Long terminal repeats Antibiotic resistance genes

Highly condensed due to many levels of coiling and loop formation

Which is a characteristic of a metaphase chromosome?

A transposable element is removed from its original site and inserted at another location

Which of the following describes simple transposition?

CCCTC binding factor (CTCF) SMC protein

Which proteins facilitate the formation of loop domains to increase the compaction of the 30-nm fiber in eukaryotic cells? Multiple select question. DNA gyrase transposase topoisomerase I CCCTC binding factor (CTCF) SMC protein

Simple transposons have genes that are not required for transposition while insertion elements only have DNA sequences required for transposition.

Which statement identifies an accurate difference between insertion elements and simple transposons?

LTR retrotransposon

Which transposable element has direct repeats and long terminal repeats at both ends and also includes coding regions for genes required for transposition? Multiple choice question. non-LTR retrotransposon insertion element simple transposon LTR retrotransposon

Antibiotic-resistance gene

Which type of DNA sequence would be found in a simple transposon but not seen in an insertion element? Multiple choice question. Inverted repeats Direct repeats Coding region for transposase enzyme Antibiotic-resistance gene Long terminal repeats

SINEs

Which type of eukaryotic transposable elements are several hundred nucleotides in length and found at many dispersed locations throughout the genome? Multiple choice question. SINEs Copia-like elements P elements LINEs insertion sequences

Long terminal repeats at both ends Coding regions for retroviral-related proteins needed for transposition

Which types of DNA sequences are characteristic of LTR retrotransposons?

Inverted repeats at both ends Direct repeats at both ends Coding region for a transposase enzyme

Which types of DNA sequences are typically found in an insertion element? Multiple select question. Inverted repeats at both ends Direct repeats at both ends Antibiotic-resistance gene Long terminal repeats at both ends Coding region for a transposase enzyme

circular

With a few exceptions, bacterial chromosomes are .......... in shape.

Circular

With a few exceptions, what is the general structure of bacterial chromosomes? Multiple choice question. Linear Circular Figure of eight shaped