Bio Quiz Questions + Review (CH 17-21)

A coding segment of DNA that is 300 nucleotides long could specify a polypeptide that is how many amino acids long at maximum?

100

The enzyme DNA polymerase begins synthesis of a DNA strand by attaching the correct nucleotide onto the

3' end of the primer

How many codons specify amino acid?

61

How many different codons are there?

64

Which would be an example of post-translational control of gene expression?

A proteins is inactivated by de-phosphorylating it

In DNA synthesis, what enzyme links together adjacent Okazaki fragments on the lagging strand?

DNA ligase

In preparation for DNA replication, what enzyme breaks the hydrogen bonds between complimentary nucleotides to separate the two strands?

Helicase

What is the name of the bond that is formed between two amino acids by a dehydration reaction?

Peptide bonds (covalent)

Compare and contrast transcription in prokaryotes and eukaryotes.

Prokaryotes: there is no nucleus, mRNA can be transcribed and translated at the same time/place. Eukaryotes: transcription and translation happen at different times and places.

Within a cell, DNA replication begins from primers that are made of

RNA

Transcription of a gene is carried out by

RNA polymerase

In Griffith's work, a living but non-virulent strain of Streptococcus pneumoniae was incubated (grown) with heat-killed cells of a virulent strain. When mice were injected with this mixture, they died. Which of the following best explains these results?

The living bacteria obtained and expressed genetic material from the heat-killed strain.

In DNA replication, what determines the order of nucleotides in the newly synthesized strand?

The nucleotide sequence on the template strand.

When T2 bacteriophage virus is raised in a medium containing radioactive sulfur, and then used to infect bacteria, which of the following will be true?

The viral proteins will be radioactive.

Which of the following is true of introns?

They are nucleotide sequences within genes that do not contribute to the final protein.

Which of the following statements about ribosomes is false?

They coordinate the copying of a specific DNA gene sequence into messenger RNA

Which is true of the telomeres?

They decrease in length after each replication cycle.

A release factor protein will enter the acceptor site of the ribosome when

a stop codon is present on the corresponding mRNA

The large subunit of the ribosome will attach to the smaller one and begin translation of the mRNA held between them when

a tRNA carrying methionine binds to the AUG codon

The enzyme telomerase

adds additional nucleotides into the ends of eukaryotic chromosomes

In DNA replication within a living cell, what enzyme catalyzes the building of the primers?

an RNA polymerase

Translation of mRNA begins

at an AUG codon

Which is true of the DNA molecule?

between the two strands, purine nucleotides are always paired with pyrimidine nucleotides.

In the DNA extraction, you used laurel sulfate in order to

break apart the nuclear and plasma membranes surrounding the DNA

In the DNA extraction, you used papain in order to

break up proteins associated with the DNA

After which of the following mutations does a gene stand the best chance of still being able to code for a functional protein?

deletion of three nucleotide base pairs

A single tropomyosin gene can code for more than one polypeptide because

different combinations of exons can be edited from the transcript by the spliceosome

Portions of the DNA that have been damaged by UV radiation, mutagenic chemicals, etc. can be replaced by

excision repair enzymes

Garrod's observations on inherited diseases and Beadle and Tatum's work on mutants in molds helped to demonstrate that

genes code for proteins

Which of the following regions of the DNA are transcribed but not translated?

introns

The spliceosome removes

introns from the RNA transcript

Normal Neurospora mold synthesizes the amino acid arginine according to the following pathway: simple precursor molecules, ornithine, citrulline, arginine. One strain of Neurospora mold with a single mutation cannot grow on minimal medium (containing simple precursor molecules), but will grow on minimal medium supplemented with ornithine, citrulline, or arginine. This suggests that the mutant

lacks the enzyme needed to convert the precursor molecules into ornithine

By radioactive labelling of either the protein or the DNA in the T2 virus, Hershey and Chase were able to show that

only the virus DNA enters the bacterial cell

Which of the following molecules may be composed of arginine, serine, proline, tryptophan, lysine, threonine and leucine all covalently linked together in a chain?

polypeptide

Micro RNA regulate gene expression by

preventing the translation of specific mRNA transcripts.

Which of the following is not directly involved in the process of translation?

promoter

DNA proofreading by DNA polymerase

removes and replaces nucleotide bases that the enzyme matched incorrectly

During DNA replication, what keeps the separated strands of the DNA molecule from re-bonding with each other?

single-stranded DNA binding proteins

In eukaryotes, all of the following are involved in successful initiation of transcription except : start codon, promoter, enhancers, transcription factor proteins, proximal control elements

start codon

What has the anticodon that binds to corresponding codons during translation?

tRNA

When a release factor protein enters the acceptor (A) site of the ribosome,

the bond between the polypeptide chain and the tRNA in the central "P" site is broken

If you add or delete one or two nucleotide bases from a gene, much of the protein it codes for will come out wrong because

the codon reading frame becomes shifted

The fact that the codons GCU, GCC, GCA, and GCG all code for the amino acid alanine means that

the genetic code is redundant

Coordination of the entire process of translation is the job of

the ribosome

When a molecule of DNA is replicated

the two resulting DNA molecules each have one strand from the parent molecule and one newly synthesized strand

Transcription refer to

to copying of a DNA sequence into mRNA

Proximal control elements and enhancers affect gene expression by regulating

transcription

In order for transcription to begin

transcription factors must be bound to the promoter

What brings the correct amino acid to the gene transcript CODON that specific it?

transfer RNA

Which is not an example of a regulatory DNA sequence?

tropomyosin gene

Which of the following is not an example of a regulatory protein?

tropomyosin protein involved in muscle relaxation

Regulatory sequences, such as proximal control elements, enhancers, and silencers, exert their effects on gene expression

when regulatory proteins bind to them