Unit 5 Foundations of Biology

In prokaryotic cells, ribosomes are found in/on the: a. cytoplasm b. mitochondrion c. nucleus d. endoplasmic reticulum

a. cytoplasm

In any given species, there are at least how many types of aminoacyl tRNA syntheases? a. 3 b. 16 c. 20 d. 64

c. 20

How many nucleotides are in 12 mRNA codons? a. 12 b. 24 c. 36 d. 48

c. 36

In prokaryotes transcription occurs in the a. nucleus b. cytoplasm c. cytosol d. matrix

b. cytoplasm

What is the flow of information for the synthesis of proteins according to the central dogma? a. DNA to mRNA to protein b. DNA to mRNA to tRNA to protein c. DNA to protein to mRNA to protein d. mRNA to DNA to mRNA to protein

a. DNA to mRNA to protein

If glucose is absent but lactose is present, the lac operon will be: a. activated b. repressed c. partially activated d. mutated

a. activated

Reduction is genetic diversity due to catastrophic population reduction. a. bottlenecks b. genetic drift c. gene flow

a. bottlenecks

mRNA directs the building of proteins through a sequence of a. codons b. exons c. introns d. anticodons

a. codons

On which end of an mRNA is the poly-A located? a. 3' b. 5'

a. 3'

RNA polymerase transcribes in the [...] direction a. 5'-3' b. 3'-5'

a. 5'-3'

The anticodon of tRNA binds with a. complementary bases on mRNA b. codons of tRNA c. complementary bases on rRNA d. amino acids

a. complementary bases on mRNA

Which process is divergent evolution? a. groups of organisms evolve in different directions from a common point b. a new species develops rapidly when an event cuts off a portion of a population c. groups of organisms independently evolve to similar forms

a. groups of organisms evolve in different directions from a common point

When comparing humans (or in Drosophila), are X-linked recessive traits observed more frequently in males, in similar numbers between males and females, more frequently in females, or is the frequency different depending on the trait? a. in more males than females b. in more females than males c. in males and females equally d. in different distributions depending on the trait

a. in more males than females

The probability of a crossover between two genes [...] the greater the distance between them. a. increases b. decreases

a. increases

Selection against phenotypic average. a. stabilizing selection b. directional selection c. diversifying selection

c. diversifying selection

Which of the following features distinguishes eukaryotic transcription form bacterial transcription? a. eukaryotic transcription does not start at a consensus sequence b. eukaryotic transcription does not require an initiation complex c. eukaryotic transcription and translation do not take place at the same time d. eukaryotic transcription does not require a termination sequence

c. eukaryotic transcription and translation do not take place at the same time

Immigration and reproduction which introduces new genetic variants. a. bottlenecks b. genetic drift c. gene flow

c. gene flow

What are two primary sources of genetic variations? a. mutations and sexual reproduction b. isolation and sexual reproduction c. sexual reproduction and asexual reproduction d. migration and sexual reproduction

a. mutations and sexual reproduction

In eukaryotes transcription occurs in the a. nucleus b. cytoplasm c. cytosol d. matrix

a. nucleus

Which eukaryotic RNA polymerase is responsible for the synthesis of rRNA? a. polymerase I b. polymerase II c. polymerase III

a. polymerase I

During transcription, RNA polymerase binds to the DNA a. promoter b. receptor c. regulator d. enhancer

a. promoter

Selection against phenotypic extremes. a. stabilizing selection b. directional selection c. diversifying selection

a. stabilizing selection

An mRNA is transcribed on the a. template strand b. coding strand

a. template strand

What are epigenetic modifications? a. the addition of reversible changes to histone proteins and DNA b. the removal of nucleosomes from the DNA c. the addition of more nucleosomes to the DNA d. mutation fo the DNA sequence

a. the addition of reversible changes to histone proteins and DNA

A tRNA is chemically modified so that the amino acid bound is different than the one specified by its anticodon. Which codon in the mRNA would the tRNA recognize: the one specified by its anticodon or the one that matches the modified amino acid it carries? a. the anticodon will match the codon in mRNA b. the anticodon will match with the modified amino acid it carries c. the anticodon will lose the specificity for the tRNA molecule

a. the anticodon will match the codon in mRNA

Which step in the transcription of eukaryotic RNA differs the most from its prokaryotic counterpart? a. the initiation step in eukaryotes requires an initiation complex with enhancers and transcription factors. Also, the separation of the DNA stand is different as histones are involved b. the initiation step in prokaryotes requires an initiation complex with enhancers and transcription factors. Also, the separation of the DNA strand is different as histones are involved c. the elongation step in eukaryotes requires an initiation complex with enhancers and transcription factors. Also, the separation of the DNA strand is different as histones are involved d. the initiation step in eukaryotes requires an initiation complex with enhancers and transcription factors. Also, the separation of the DNA strand is different as histones are not involved

a. the initiation step in eukaryotes requires an initiation complex with enhancers and transcription factors. Also, the separation of the DNA stand is different as histones are involved

In the prokaryotic trp operon: what happens when tryptophan is present? a. the repressor binds to the operator, and RNA synthesis is blocked b. RNA polymerase binds to the operator, and RNA synthesis is blocked c. tryptophan binds to the repressor, and RNA synthesis proceeds d. tryptophan binds to RNA polymerase, and RNA synthesis proceeds

a. the repressor binds to the operator, and RNA synthesis is blocked

A pericentric inversion involves the centromere. a. true b. false

a. true

Increased incidence of Down Syndrome correlates with maternal age. a. true b. false

a. true

Nondisjunction occurs when homologous chromosomes or sister chromatids fail to separate during meiosis. a. true b. false

a. true

A poly-A sequence is added at the: a. 5' end of a transcript in the nucleus b. 3' end of a transcript in the nucleus

b. 3' end of a transcript in the nucleus

On which end of an mRNA is the cap located? a. 3' b. 5'

b. 5'

Until recently, these three species of short-tailed pythons, Python curtus, Python brongersmai (middle), and Python breitensteini were considered one species. However, due to the different locations in which they are found, they have become three distinct species. What is this an example of? a. divergent evolution b. sympatric speciation c. allopatric speciation d. variation

c. allopatric speciation

What is the best definition of adaptation? a. a trait or behavior that aids an organism's survival and reproduction b. a heritable trait or behavior that aids an organism's survival and reproduction c. a trait or behavior that aids a population's survival and reproduction d. a heritable trait or behavior the aids a population's survival and reproduction

b. a heritable trait or behavior that aids an organism's survival and reproduction

An mRNA has the same sequence as the a. template strand b. coding strand

b. coding strand

The AUC and AUA codons in mRNA both specify isoleucine. What feature of the genetic code explains this? a. complementarity b. degeneracy/redundant c. nonsense codons d. universality

b. degeneracy/redundant

Selection against one phenotypic extreme. a. stabilizing selection b. directional selection c. diversifying selection

b. directional selection

Which best distinguishes prokaryotic and eukaryotic cells? a. prokaryotes possess a nucleus whereas eukaryotes do not, but eukaryotes show greater compartmentalization that allows for greater regulation of gene expression b. eukaryotic cells contain a nucleus whereas prokaryotes do not, and eukaryotes show greater compartmentalization that allows for greater regulation of gene expression c. prokaryotic cells are less complex and perform highly-regulated gene expression whereas eukaryotes perform less-regulated gene expression d. eukaryotic cells are more complex and perform less-regulated gene expression whereas prokaryotic cells perform highly-regulated gene expression

b. eukaryotic cells contain a nucleus whereas prokaryotes do not, and eukaryotes show greater compartmentalization that allows for greater regulation of gene expression

A paracentric inversion involves the centromere. a. true b. false

b. false

A reciprocal translocation results in a loss of genetic information. a. true b. false

b. false

increased incidence of Down Syndrome correlates with paternal age. a. true b. false

b. false

Reduction in genetic diversity due to chance events. a. bottlenecks b. genetic drift c. gene flow

b. genetic drift

Allopatric speciation is dependent on a. gene flow b. geographic separation c. islands d. genetic drift

b. geographic separation

What would happen if the operator sequence of the lac operon contained a mutation that prevented the repressor protein from binding the operator? a. in the presence of lactose, the lac operon will not be transcribed b. in the absence of lactose, the lac operon will be transcribed c. the RNA polymerase will not bind the promoter

b. in the absence of lactose, the lac operon will be transcribed

At what stage in the transcription of a eukaryotic gene would TFII factors be active? a. elongation b. initiation c. processing d. termination

b. initiation

Which scientific concept did Charles Darwin and Alfred Wallace independently discover? a. mutation b. natural selection c. overbreeding d. sexual reproduction

b. natural selection

Which eukaryotic RNA polymerase is responsible for the synthesis of mRNA? a. polymerase I b. polymerase II c. polymerase III

b. polymerase II

The sequence that signals the end of translation is called the: a. promoter b. stop codon c. TATA box d. terminator

b. stop codon

In the prokaryotic lac operon: what would be the result of a mutation in the repressor protein that prevented it from binding lactose? a. the repressor will bind to lactose when it is removed from the operator b. the repressor will bind the operator in the presence of lactose c. the repressor will not bind the operator in the presence of lactose d. the repressor will not bind the operator in the absence of lactose

b. the repressor will bind the operator in the presence of lactose

Which of the following is true of epigenetic changes? a. they only allow gene expression b. they allow movement of histones c. they change the DNA sequence d. they are always heritable

b. they allow movement of histones

Why are the -10 and -35 regions of prokaryotic promoters called consensus sequences? a. they are identical in all bacterial species b. they are similar in all bacterial species c. they exist in all organisms d. they have the same function in all organisms

b. they are similar in all bacterial species

The result of nondisjunction are four gametes which have a. 4 cells with an n+1 condition b. 4 cells with an n-1 condition c. 2 cells with an n+1 and 2 cells with an n-1 condition d. 2 cells with an n+1 and 2 cells with a normal condition

c. 2 cells with an n+1 and 2 cells with an n-1 condition

Cri-du-chat syndrome is due to a(n) [...] on chromosome 5. a. translocation b. inversion c. deletion

c. deletion

What would happen if the operator sequence of the trp operon contained a mutation that prevented the repressor protein from binding to the operator? a. in the absence of tryptophan, the genes trpA-E will not be transcribed b. in the absence of tryptophan, only genes trpE and trpD will be transcribed c. in the presence of tryptophan, the genes trpA-E will be transcribed d. in the presence of tryptophan, the trpE gene will not be transcribed

c. in the presence of tryptophan, the genes trpA-E will be transcribed

Which of the following statements describes prokaryotic transcription of the lac operon? a. when lactose and glucose are present in the medium, transcription of the lac operon is induced b. when lactose is present but glucose is absent, the lab operon is repressed c. lactose acts as an inducer of the lac operon when glucose is absent d. lactose acts as an inducer of the lac operon when glucose is present

c. lactose acts as an inducer of the lac operon when glucose is absent

Assume a pericentric inversion occurred in one of the two homologs prior to meiosis. The other homolog remains normal. During meiosis, what structure, if any, would these homologs assume in order to pair accurately along their lengths? a. V formation b. cruciform c. loop d. a pairing would not be possible

c. loop

What is often the first amino acid added to a polypeptide chain? a. adenine b. leucine c. methionine d. thymine

c. methionine

Which eukaryotic RNA polymerase is responsible for the synthesis of tRNA? a. polymerase I b. polymerase II c. polymerase III

c. polymerase III

Which of the following is found in both prokaryotes and eukaryotes? a. 3' poly-A tails b. 5' caps c. promoters d. introns

c. promoters

Which of the following molecules does not contain genetic information? a. DNA b. mRNA c. protein d. RNA

c. protein

Both genetic drift and bottlenecks are dependent on a. large populations c. small populations d. mutations

c. small populations

A [...] removes introns a. ribosome b. RNA polymerase c. spliceosome

c. spliceosome

Gene A is thought to be associated with color blindness. The protein corresponding to gene A is isolated. Analysis of the protein recovered shows there are actually two different proteins that differ in molecular weight that correspond to gene A. What is one reason why there may be two proteins corresponding to the gene? a. one protein had a 5' cap and a poly-A tail in its mRNA, and the other protein did not b. one protein had a 5' UTR and a 3' UTR in its RNA, and the other protein did not c. the gene was alternatively spliced d. the gene produced mRNA molecules with differing stability

c. the gene was alternatively spliced

In the prokaryotic trp operon: what happens in the absence of tryptophan? a. RNA polymerase binds to the repressor b. the repressor binds to the promoter c. the repressor dissociates from the operator d. RNA polymerase dissociates from the promoter

c. the repressor dissociates from the operator

The tortoise coat color cat is an example of a. translocation b. inversion c. deletion d. X inactivation e. nondisjunction

d. X inactivation

Which option is the best definition of species? a. a group of individual organisms with significant genetic similarities b. a group of individual organisms with significant genetic similarities that share external and internal characteristics c. a group of individual organisms that interbreed d. a group of individual organisms that interbreed and produce viable, fertile offspring

d. a group of individual organisms that interbreed and produce viable, fertile offspring

A species which investigates multiple open niches can rapidly change into a variety of new species. This is known as a. genetic drift b. gene flow c. allopatric speciation d. adaptive radiation

d. adaptive radiation

Which one is correct matching? a. transcription - synthesis of protein b. translation - process of mRNA carrying information from nucleus to ribosome c. ribosomal RNA - carries amino acid to site of protein synthesis d. anticodon - site of tRNA having complementary bases to a codon of mRNA

d. anticodon - site of tRNA having complementary bases to a codon of mRNA

Control of gene expression in eukaryotic cells occurs at which level(s)? a. only the transcriptional level b. epigenetic and transcriptional levels c. epigenetic and transcriptional and translational levels d. epigenetic and transcriptional, translational, and post-translational levels

d. epigenetic and transcriptional, translational, and post-translational levels

The addition of a ubiquitin group of a protein does what? a. increases the stability of the protein b. decreases translation of the protein c. increases translation of the protein d. marks the protein for degradation

d. marks the protein for degradation

Where are the RNA components of ribosomes synthesized? a. cytoplasm b. endoplasmic reticulum c. nucleus d. nucleolus

d. nucleolus

Which subunit of the E.coli polymerase confers specificity to transcription? a. A (alpha) b. B (beta) c. B' (beta prime) d. o (sigma)

d. o (sigma)

Which of the following is not a processing event in the formation of an mRNA? a. addition of a 3' poly-A tail b. addition of a 5' cap c. splicing out introns d. splicing out exons

d. splicing out exons

The sequence that signals the end of transcription is called the: a. promoter b. stop codon c. TATA box d. terminator

d. terminator

What are introns? a. DNA sequences to which polymerases bind b. the processed mRNA c. translated DNA sequences in a gene d. untranslated DNA sequences in a gene

d. untranslated DNA sequences in a gene