BIO 200: Chapter 3 DNA

The polarity in a DNA strand is indicated by referring to one end as the 3' end and the other as the 5' end. Which structure is on the 3' end? a. hydroxyl group b. phosphate group c. nitrogenous base

a. hydroxyl group

The classic "beads-on-a-string" structure is the most decondensed chromatin structure possible and is produced experimentally. Which chromatin components are NOT retained when this structured is generated? a. linker histones b. linker DNA c. nucleosome core particles d. core histones

a. linker histones

Each chromosome contains: a. one long DNA molecule b. one long RNA molecule c. one long sequence of amino acids d. a single gene for a protein

a. one long DNA molecule

Which of these structures cannot be resolved with a conventional light microscope? a. ribosome b. mitochondria c. bacterium d. nucleus

a. ribosome

the human genome comprises 23 pairs of chromosomes found in nearly every cell in the body. how many centromeres are in each cell? a. 23 b. 46 c. 69 d. 92 e. >200

b. 46

What evidence suggests that the large amount of excess "junk" DNA in a genome may serve an important function? a. all organisms have excess "junk" DNA b. a portion of "junk" DNA is highly conserved in its DNA sequence among many different eukaryotic species

b. a portion of "junk" DNA is highly conserved in its DNA sequence among many different eukaryotic species

What is the name of the process by which eukaryotic cells engulf very large particles, or even entire foreign cells? a. pinocytosis b. endocytosis c. exocytosis d. lymphocytosis

b. endocytosis

Stepwise condensation of linear DNA happens in five different packing processes. Which of the following four processes has a direct requirement for histone H1? a. formation of "beads-on-a-string" b. formation of the 30nm fiber c. looping of the 30nm fiber d. packing of loops to form interphase chromosomes

b. formation of the 30 nm fiber

a cell can pass certain types of chromatin structure to daughter cells during cell reproduction. what molecules are key to this type of inheritance? a. DNA molecules b. histone proteins c. RNA molecules

b. histone proteins

What structure in an interphase cell contains ribosomal RNA and proteins for the formation of ribosomes? a. chromatin b. nucleolus c. nuclear lamina

b. nucleolus

histone proteins pack DNA into a repeating array of DNA-protein particles called: a. heterochromatin b. nucleosomes c. euchromatin d. nucleoli

b. nucleosomes

In which type(s) of cells can a chloroplast be found? a. animal cell b. plant cell c. bacterial cell

b. plant cell c. bacterial cell

The DNA in eukaryotic chromosomes is folded into a compact form by interactions with: a. RNA b. proteins c. euchromatin d. microtubules e. centromeres

b. proteins

Photosynthesis enables plants to capture the energy from sunlight. In this essential process, plants incorporate the carbon from COs into high-energy _________ molecules, which the plant cel mitochondria use to produce ATP. a. fat b. sugar c. protein d. fiber

b. sugar

what form of inheritance describes how a cell passes down chromatin structure (i.e. heterochromatin or euchromatin) from parent to daughter cells? a. genetic inheritance b. perigenetic inheritance c. epigenetic inheritance d. filial inheritance

c. epigenetic inheritance

what type of bond connects base pairs? a. covalent bond b. ionic bond c. hydrogen bond

c. hydrogen bond

The core histones are small, basic proteins that have a globular domain at the C-terminus and a long extended conformation at the N-terminnus. Which of the following is NOT true of the N terminal "tail" of these histones? a. it is subject to covalent modifications b. it extends out of the nucleosome core c. it binds to DNA in a sequence-specific manner d. it helps DNA pack tightly

c. it binds to DNA in a sequence-specific manner

The _______ _________is made up of two concentric membranes and is continuous with the membrane of the endoplasmic reticulum. a. plasma membrane b. golgi network c. mitochondrial membrane d. nuclear envelope

d. nuclear envelope

All functional DAN sequences inside a cell code for protein products -true -false

false

Eukaryotic cells

-Membrane bound nucleus -both single cell (protists) and multicellular organisms -larger genomes, more regulatory DNA sequences -bigger, more elaborate cells w/ multiple organelles -includes plants, animals, and fungi

In the chromatin of interphase chromosomes, regions of the chromosome that contain genes being expressed are generally more compact, while those that contain quiescent genes are generally more extended -true -false

-false

Prokaryotic cells

-no membrane around DNA -most are single-celled, sometimes cluster together -cell walls are common, greater diversity/habitat -smaller genomes

Codons are three-base sequences that specify the addition of a single amino acid. How do eukaryotic codons and prokaryotic codons compare? Prokaryotic codons usually contain different bases than those of eukaryotes. Prokaryotic codons usually specify different amino acids than those of eukaryotes. The translation of codons is mediated by tRNAs in eukaryotes, but translation requires no intermediate molecules such as tRNAs in prokaryotes. Codons are a nearly universal language among all organisms.

Codons are a nearly universal language among all organisms.

Which one of the following best describes why a typical eukaryotic gene is able to respond to a far greater variety of regulatory signals than a typical prokaryotic gene or operon? Eukaryotes have three types of RNA polymerase. Eukaryotic RNA polymerases require general transcription factors. Eukaryotic transcription can be influenced by additional factors that bind far from the promoter. Prokaryotic genes are packaged into nucleosomes.

Eukaryotic transcription can be influenced by additional factors that bind far from the promoter.

How do changes in histone modifications lead to changes in chromatin structure? They directly lead to changes in the positions of the core histones. They change the affinity between the histone octamer and the DNA. They help recruit other proteins to the chromatin. They cause the histone N-terminal tails to become hyperextended.

They help recruit other proteins to the chromatin.

how do chromatin-remodeling complexes work?

They use the energy from ATP hydrolysis to alter nucleosomes and make certain regions of the DNA more accessible to other proteins

which of the following is NOT true? a. a cell can temporarily decondense its chromatin to silence genes during differentiation b. a cell can temporarily decondense its chromatin to give proteins rapid, localized access to specific DNA sequences c. a cell can temporarily decondense its chromatin to allow access to specific DNA sequences for replication, repair, or gene expression

a. a cell can temporarily decondense its chromatin to silence genes during differentiation

Although there are many distinct prokaryotic species, most have a small range of shapes, sizes, and growth rates. Which of the following characteristics are not observed in procaryotes? a. a highly structured cytoplasm b. endoplasmic reticulum c. the ability to divide rapidly d. a cell wall

a. a highly structured cytoplasm, b. endoplasmic reticulum

In which type(s) of cells can a Golgi apparatus be found? a. animal cell b. plant cell c. bacterial cell

a. animal cell b. plant cell

In which type(s) of cells can a lysosome can be found? a. animal cell b. plant cell c. bacterial cell

a. animal cell b. plant cell

In which type(s) of cells can a mitochondrion be found? a. animal cell b. plant cell c. bacterial cell

a. animal cell b. plant cell

In which type(s) of cells can a nucleus be found? a. animal cell b. plant cell c. bacterial cell

a. animal cell b. plant cell

the structure that allows each duplicated eukaryotic chromosome to be pulled into a daughter cell is called a: a. centromere b. telomere c. mitotic spindle d. histone

a. centromere

What is the most highly condensed form of chromatin? a. heterochromatin b. 30-nm chromatin fibers c. euchromatin

a. heterochromatin

what histone protein (considered a "linker" histone) is thought to pull nucleosomes together into a regular repeating array, resulting in a 30 nm fiber? a. histone H1 b. histone H2A c. histone H2B d. histone H3 e. histone H4

a. histone H1

Which statement is true about the tight association of histone proteins and DNA? a. histone proteins have a high proportion of positively charged amino acids, which attract the negatively charged phosphate groups on DNA. b. histone proteins have deep grooves into which a DNA double helix tightly fits.

a. histone proteins have a high proportion of positively charged amino acids, which attract the negatively charged phosphate group on DNA.

the images of chromosomes we typically see are isolated from mitotic cells. these mitotic chromosomes are in the most highly condensed form. Interphase cells contain chromosomes that are less densely packed and _______. a. occupy discrete territories in the nucleus b. share the same nuclear territory as their homolog c. are restricted to the nucleolus d. are completely tangled with other chromosomes

a. occupy discrete territories int he nucleus

Interphase chromosomes are about ___ times less compact than mitotic chromosomes, but still are about ____ times more compact than a DNA molecule in its extended form. a. 10; 1000 b. 20; 500 c. 5; 2000 d. 50; 200

b. 20; 500

The human genome contains approximately how many genes? a. 500 b. 25,000 c. 100,000 d. 3,000,000,000

b. 25,000

the N-terminal tail of histone H3 can be extensively modified, and depending on the #, location, and combination of these modifications, these changes may promote the formation of heterochromatin. what is the result of heterochromatin formation? a. increase in gene expression b. gene silencing c. recruitment of remodeling complexes d. displacement of histone H1

b. gene silencing

Which of the following has a nucleus? a. chloroplast b. yeast c. archaea d. bacteria

b. yeast

You have a segment of DNA that contains the following sequence: 5′-GGACTAGACAATAGGGACCTAGAGATTCCGAAA-3′ 3′-CCTGATCTGTTATCCCTGGATCTCTAAGGCTTT-5′ You know that the RNA transcribed from this segment contains the following sequence: 5′-GGACUAGACAAUAGGGACCUAGAGAUUCCGAAA-3′ top strand is the template strand; RNA polymerase moves along this strand from 5′ to 3′ top strand is the template strand; RNA polymerase moves along this strand from 3′ to 5′ bottom strand is the template strand; RNA polymerase moves along this strand from 5′ to 3′ bottom strand is the template strand; RNA polymerase moves along this strand from 3′ to 5′

bottom strand is the template strand; RNA polymerase moves along this strand from 3′ to 5′

nucleosomes are formed when DNA wraps ___ times around the histone octamer in a __ coil. a. 2.0; right-handed b. 2.5; left-handed c. 1.7; left-handed d. 1.3; right-handed

c. 1.7; left-handed

When there is a well-established segment of heterochromatin on an interphase chromosome, there is usually a special barrier sequence that prevents the heterochromatin from expanding along the entire chromosome. Gene A, which is normally expressed, has been moved by DNA recombination near an area of heterochromatin. None of the daughter cells produced after this recombination event express gene A, even though its DNA sequence is unchanged. What is this the best way to describe what has happened to the function of gene A in these cells? a. barrier destruction b. heterochromatization c. epigenetic inheritance d. euchromatin depletion

c. epigenetic inheritance

What statement about nucleosomes is false? a. a nucleosome is a "bead" on a string of unfolded chromatin b. a nucleosome proceeds a 3-fold packing ratio of DNA c. nucleosomes are found only in mitotic chromosomes d. a nucleosome consists of DNA wrapped around 8 histone proteins, plus a short segment of linker DNA.

c. nucleosomes are found only in mitotic chromosomes

although the chromatin structure of interphase and mitotic chromosomes is very compact, DNA-binding proteins and protein complexes must be able to gain access to the DNA molecule. Chromatin-remodeling complexes provide this access by_______. a. recruiting other enzymes b. modifying the N-terminal tails of core histones c. using the energy of ATP hydrolysis to move nucleosomes d. denaturing the DNA by interfering with H-bonding between base pairs

c. suing the energy of ATP hydrolysis to move nucleosomes

the process of sorting human chromosomes pairs by size and morphology is karyotyping. a modern method employed for karyotyping is called chromosome painting. how are individual chromosomes "painted"? a. with a laser b. using fluorescent antibodies c. using fluorescent DNA molecules d. using green fluorescent protein

c. using fluorescent DNA molecules

The RNA component within snRNP complexes ___________________. are translated into proteins needed for splicesome assembly. are important for producing mature mRNA transcripts in bacteria. are removed by the spliceosome during RNA splicing. can complementarily bind to specific sequences at intron/exon boundaries.

can complementarily bind to specific sequences at intron/exon boundaries.

the octameric histone core is composed of four different histone proteins, assembled in a stepwise manner. Once the core octamer has been formed, DNA wraps around it to form a nucleosome core particle. which of the following histone proteins does NOT form part of the octameric core? a. H4 b. H2A c. H3 d. H1

d. H1

The core histone proteins have tails that can be chemically modified by what type of group? a. acetyl b. phosphate c. methyl d. any of the above

d. any of the above

Despite the differences between eukaryotic and prokaryotic cells, procaryotes have proteins that are distantly related to eukaryotic actin filaments and microtubules. What is likely to be the most ancient function of the cytoskeleton? a. cell motility b. vesicle transport c. membrane support d. cell division

d. cell division

The complex of DNA and protein in chromosomes is called: a. centromeres b. histone c. centrosome d. chromatin

d. chromatin

What unit of length would you generally use to measure a typical human cell? a. centimeters b. nanometers c. millimeters d. micrometers

d. micrometers

how many replication origins are in each cell? (23 pairs of chromosomes found in every cell) a. 23 b. 46 c. 69 d. 92 e. >200

e. >200

Although bacteria use a variety of organic substances as food, bacteria are not able to live on inorganic substances. -true -false

false

Comparing the relative number of chromosome pairs is a good way codetermine whether two species are closely related. -true -false

false

Hydrogen bonds between each nucleotide hold individual DNA strands together -true -false

false

Mitochondria are though to have evolved from anaerobic bacteria. -true -false

false

Primitive plant, animal, and fungal cells probably acquired mitochondria after they diverged from a common ancestor. -true -false

false

cytoskeleton

filamentous proteins that provide structural framework for cell

Total nucleic acids are extracted from a culture of yeast cells and are then mixed with resin beads to which the polynucleotide 5'-TTTTTTTTTTTTTTTTTTTTTTTTT-3' has been covalently attached. After a short incubation, the beads are then extracted from the mixture. When you analyze the cellular nucleic acids that have stuck to the beads, which of the following is most abundant? DNA tRNA rRNA mRNA

mRNA because addition is mRNA modification

In a DNA double helix, ____

the two strands run antiparallel

Endocytosis

transport from plasma membrane inward

exocytosis

transport to the plasma membrane for secretion

Each strand of DNA contains all the information needed to create a new double-stranded DNA molecule with the same sequence information. -true -false

true

Histone tail modifications establish and maintain the different chromatin structures found in heterochromatin and euchromatin. -true -false

true

eukaryotic chromosomes contain many different sites where DNA replication can be initiated. -true -false

true

the polarity of a DNA strand results from the polarity of the nucleotide subunits -true -false

true

Which of the following statements about the genetic code is correct? All codons specify more than one amino acid. The genetic code is redundant. All amino acids are specified by more than one codon. All codons specify an amino acid.

The genetic code is redundant.