Midterm 1 Bio 99

Which of the following is not a reason why proteins were thought to be the cell's carrier of genetic information?

The genetic information was known to be contained in chromosomes (which consist of DNA and proteins).

Protein synthesis only requires proteins.

DNA was too simple

All of the above support the idea that proteins could be the genetic information.

Protein synthesis only requires proteins.

Hershey and Chase's experiment demonstrated that DNA is the hereditary information.  Which experimental result allowed them to conclude this?
Bacteriophages can infect cells.

Radioactive sulfur was found in the bacterial pellets.

Radioactive phosphorus was found in the bacterial pellets.

Bacteriophage DNA can be radioactively labeled.

Radioactive phosphorus was found in the bacterial pellets.

A deoxyribonucleotide is composed of (select all that apply):

Nitrogenous base

Ribose

Phosphate group

Pentose with 3' OH

Nitrogenous base

Phosphate group

Pentose with 3' OH

The carbons of the pentose group of DNA and RNA nucleotides are identical except for:

The functional group attached to C1

The functional group attached to C2

The functional group attached to C3

The functional group attached to C4

The functional group attached to C5

The functional group attached to C2

Which of the following are true regarding nucleic acid hybridization?

It is possible to visualize a region of genomic DNA using a fluorescent probe.

It is possible to hybridize a DNA strand to an RNA strand.

It is possible for DNA from different species to hybridize.

A fluorescent probe binds randomly to DNA.

It is possible to visualize a region of genomic DNA using a fluorescent probe.

It is possible to hybridize a DNA strand to an RNA strand.

It is possible for DNA from different species to hybridize.

Which of the following was observed by Erwin Chargaff?

Base composition of DNA does not vary from one species to another.

DNA isolated from different tissues of the same species have the same base composition.

Base composition changes as the organism ages.

In all species, the concentration of adenine equals the concentration of guanine.

In all species, A + T = G + C.

DNA isolated from different tissues of the same species have the same base composition.

Successive nucleotides of a DNA chain are joined by:

Phosphodiester bonds between the 5 carbon of one nucleotide and the 2 carbon of the next

Glycosidic bond between the 5 carbon of one nucleotide and the 3 carbon of the next

Hydrogen bonds between the complementary bases

Ionic bonds between the phosphate group of one nucleotide and the sugar group of the next

Phosphodiester bond between the 3 carbon of one nucleotide and the 5 carbon of the next

Phosphodiester bond between the 3 carbon of one nucleotide and the 5 carbon of the next

Which of the following is not a component of a ribonucleotide?

Phosphate group

Ribose

Uracil

Thymine

Adenine

Thymine

Avery found that DNA was necessary and sufficient for bacterial transformation.  Which of the following experimental results support this statement? Select all that apply.

Removal of DNA from cell extracts prevented transformation

Removal of RNA from cell extracts prevented transformation

Protein alone will cause transformation to occur

DNA alone will cause transformation to occur

Removal of DNA from cell extracts prevented transformation

DNA alone will cause transformation to occur

Which of the following is not a feature of the DNA helix proposed by Watson and Crick?

Double stranded

Right-handed

Antiparallel

Complimentary base pairing

Two grooves of equal dimensions

Two grooves of equal dimensions

Choose the answer that has the information flow of the central dogma in the correct order.

DNA, translation, RNA, replication, protein

DNA, transcription, RNA, replication, protein

RNA, translation, DNA transcription, protein

DNA, transcription, RNA, translation, protein

RNA, transcription, DNA, translation, protein

DNA, transcription, RNA, translation, protein

Which is the less stable molecule, DNA or RNA?

DNA, because it is double stranded

RNA, because it is single stranded

DNA, because it has a 2' H group

RNA, because it has a 2'OH group

Both molecules are equally stable

RNA, because it has a 2'OH group

Which of the following types of RNA are involved in translation?  Select all that apply.

mRNA

rRNA

tRNA

mRNA

rRNA

tRNA

Genomics is the field dedicated to the study of:

DNA on a cellular scale.

protein expression.

RNA synthesis and function.

viral genomes.

DNA sequencing methods.

DNA on a cellular scale.

The human genome is mostly composed of:

Active retrotransposons

Protein coding genes

introns

transposons and retrotransposons that are mostly inactive

long repetitive sequenes like centromeres and telomeres

transposons and retrotransposons that are mostly inactive

In the following pathway, mutation of enzyme II would result in the accumulation of __________ and the mutant would require __________ in the media in order to grow.

 
citrulline, arginine

ornithine, citrulline

arginine, ornithine

arginine, citrulline

ornithine, precursor

ornithine, citrulline

Which of the following is not a reason why H. influenzae was chosen to be the first genome sequenced.

The percentage of AT nucleotides is similar to humans.

The genome sequence had already been partially uncovered.

It has a relatively small genome compared to more complex organisms.

All of the above are reasons why H. influenzae was chosen.

The genome sequence had already been partially uncovered.

Which of the following does not describe an aspect of the Human Genome Project?

Overlapping clones from YAC and BAC libraries were identified by hybridization and organized into long contiguous stretches called contigs.

Landmark sequences on the contig called sequence tagged sites (STS) were used to aid in ordering the contigs.

The contigs were sequenced using a shotgun method, and the resulting sequences were assembled by computer.

All of the above describe aspects of the Human Genome Project.

All of the above describe aspects of the Human Genome Project.

Which of the following are reasons why the "one gene, one enzyme" hypothesis is not completely accurate?  Select all that apply.

Some enzymes require more than one gene to be functional.

Some enzymes synthesize lipids.

Some genes synthesize RNAs that do not produce proteins.

Some genes are capable of making multiple different enzymes.

Some enzymes require more than one gene to be functional.

Some genes synthesize RNAs that do not produce proteins.

Some genes are capable of making multiple different enzymes.

The genomes of many organisms have been sequenced.  What benefits or uses could result from this information?

Genome-based personalized medicine.

Trace our evolutionary history.

Elucidate genetic patterns related to diseases.

Identify genes that can improve agricultural yield.

All of the above.

All of the above.

Which of the following are examples of auxotrophs?  Select all that apply.

A yeast cell that is unable to synthesize the amino acid leucine.

A bacterium that does not have antibiotic resistance genes.

A neurospora strain that requires lysine from the environment in order to grow.

A yeast cell that is unable to synthesize the amino acid leucine.

A neurospora strain that requires lysine from the environment in order to grow.

Chromatin consists of:

DNA

Protein

DNA and RNA

DNA and protein

RNA and protein

DNA and protein

Of the proteins associated with chromatin, which of the following represents the largest component?

Histones

Topoisomerases

SMC proteins

Transcriptional regulators

Histones

The first evidence for nucleosome formation came from digesting chromosomal DNA with a non-specific nuclease.  Gel electrophoresis of the DNA after the reaction revealed:

A ladder of protected fragments about 1000 bp apart.

A ladder of protected fragments about 200 bp apart.

A single large band 200bp in length.

Random distribution of bands of different sizes.

Four bands, each composed of a different histone.

A ladder of protected fragments about 200 bp apart.

Each nucleosome contains:

Four proteins: H2A, H2B, H3 and H4.

A histone octamer composed of two copies of each of the following proteins: H1, H2, H3 and H4.

A histone octamer composed of two copies of each of the following proteins: H2A, H2B, H3 and H4.

Four proteins: SMC1, SMC2, SMC3 and SMC4.

A mixture of histones and SMC proteins.

A histone octamer composed of two copies of each of the following proteins: H2A, H2B, H3 and H4.

The contacts between the DNA and the histones of the nucleosome are:

Mainly between the R groups of the histones and the phosphate backbone of the DNA.

Mainly between the conserved histone folds and the phosphate backbone of the DNA helix.

More prevelant in regions of the DNA that have tracts of GC pairs. These regions tend to bend more readily.

Primarily between the DNA bases and the histone peptide backbone.

None of the given answers.

Mainly between the conserved histone folds and the phosphate backbone of the DNA helix.

Which of the following is not true of histone tails?

They have enzymatic properties that can covalently modify DNA.

They are the target of numerous chemical modifications.

They experience changes in net charge, shape and other properties of histones in response to modifications.

They are recognized by certain enzymes.

They have enzymatic properties that can covalently modify DNA.

Which of the following is not a way nucleosome formation affects DNA?

The DNA is compacted.

The access to DNA by enzymes is altered.

Binding of H1 destabilizes the nucleosome, alleviating the transcriptional repression exerted by the binding of nucleosome histones.

Transcription is inhibited by the tight, internucleosome connections mediated by histone tails.

Binding of the transcription factor Sp-1 can alleviate the transcriptional repression exerted by the histone binding.

Binding of H1 destabilizes the nucleosome, alleviating the transcriptional repression exerted by the binding of nucleosome histones.