biology exam FINAL

The figure above shows a simple metabolic pathway. According to Beadle and Tatum's hypothesis, at a minimum how many genes are necessary for this pathway?

2

Consider the following pice of DNA 3'GATCCGGTT 5'CTAGGCCAA Using the top strand as template, what would be the corresponding RNA?

5'CUAGGCCAA

Of the following, which is the most current description of a gene?

A DNA sequence that contains at a minimum a promoter, a transcribed region, termination signals and other regulatory elements. The information present is used to form a functional product: either RNA or a polypeptide.

Which of the following does not occur in prokaryotic gene expression, but does occur in eukaryotic gene expression?

A cap is added to the 5' end of the mRNA.

The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following?

A gene from an organism can be expressed by any other organism and the resulting protein is functional.

Coke has a pH of about 3. Blood has a pH near 7. How much more acidic is coke compared to blood?

Coke is 10,000 times more acidic

In trying to determine whether DNA or protein is the genetic material, Hershey and Chase made use of which of the following facts?

DNA contains phosphorus, whereas protein does not.

If the pH of a solution is decreased from 9 to 8, it means that the concentration of

H+ has increased tenfold (10X) compared to what it was at pH 9

In E. coli, there is a mutation in a gene called dnaB that alters the helicase enzyme that normally acts at the origin of replication. Which of the following would you expect as a result of this mutation?

No replication fork will be formed.

if a mutation of a single base occurs in an intron what would you predict would be a possible consequence to the protein that the gene encodes?

Nothing, as the RNA containing the mutation would be spliced out and not translated. As long as the mutation did not occur as the splice junction.

A mutation occurs in the the 5'UTR of a eukaryotic Gene. Predict what might occur to the protein encoded by this gene.

Nothing, this region is not translated so no change to the protein will occur.

According to the central dogma, what molecule should go in the blank? DNA → _____ → Proteins

RNA

In the process of transcription, _____.

RNA is synthesized

Which of the following statements best describes the factor independent termination of transcription in prokaryotes?

RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript.

Functional RNA

RNA that has a function like the RNA in telomarse

Eukaryotic Transciption:

Requires a large set of protien factors to properly recuit the polymerase to the promoter

Solution A has a pH of 8 Solution B has a pH of 10 Which is the most basic solution and by how much?

Solution B and 100X (or fold)

What occurs during the initiation phase of transcription in a prokaryote?

The Holo RNA polymerase recognizes the DNA promoter sequence and starts linking together NTP as directed by the template strand of the DNA

What occurs during the Termination phase of transcription in a prokaryote?

The core RNA polymerase lets go of the RNA and transcription ends in response to either factor dependent termination or factor independent termination signals.

What occurs during the Elongation phase of transcription in a prokaryote?

The core RNA polymerase moves along the DNA synthesizing RNA in a 5' to 3' direction

In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cell after she has removed its 5' cap and poly-A tail. Which of the following would you expect her to find?

The molecule is digested by enzymes because it is not protected at the 5' end.

In prokaryotes, the consensus -10 promoter sequence is TATAAT. What would your predict might happen if this sequence was mutated to GAGAAT?

The rate or amount of transcription from the mutated promoter would be less than the wild type consensus sequence

You have treated a region of chromatin with a nuclease (an enzyme that digests DNA) and you observe very little digestion or break down of the DNA. You conclude

The the region is probably heterochromatin as it resists digestion

Linear Chromosomes may shrink with each round of replication, because?

When the RNA primers are removed at the very end of the chromosome by DNA polymerase I, there is nothing to act as primer so no DNA is synthesized at that location

Linear Chromosomes shrink with each round of replication, because?

When the RNA primers are removed at the very end of the chromosome by DNA polymerase I, there is nothing to act as primer so no DNA is synthesized at that location

A definition of a base is

a molecule that accept a hydrogen ion or generate a molecle that can accept a hydrogen ion

5' Cap

a protective structure at the 5' end of RNA

How does termination of translation take place?

a stop codon is reached

Poly A Tail

a string of adenine residues added to the 3' end of an RNA independent of the gene sequence

A nucleosome is:

about 180 to 220 base pairs of DNA wraped around a Histone octomer

A ribozyme is _____.

an RNA with catalytic activity

Alternative RNA splicing _____

can allow the production of proteins of different sizes and functions from a single mRNA

Which of the following occurs in prokaryotes but not in eukaryotes?

concurrent transcription and translation

Promoter

designates the start site of transcription

Exon

encodes the sequence of amino acids

Garrod hypothesized that "inborn errors of metabolism" such as alkaptonuria occur because

genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes

What type of bonding is responsible for maintaining the shape of the tRNA molecule shown in the figure above?

hydrogen bonding between base pairs

The proper order of the phases of the transcription cycle is

initiation, elongation, and termination

The proper order of the phases of the transcription cycle is

initiation, elongation, termination

Intron

intervening sequences that are spliced out of RNA

Which part of a mRNA is removed through splicing of the pre-mRNA?

intron

Telomerase is sometimes called a ribo protein because?

it contains both RNA and poly-peptide elements

mRNA

messenger RNA- carries messages

Telomere shortening is a problem in which types of cells?

one eukaryotic cells

Adenine

purine

Guanine

purine

Cytosine

pyrimidine

Thymine

pyrimidine

Uracil

pyrimidine

The sigma sub unit of e. Coli Holo RNA polymerase is important for what function of the enzyme?

recognition of the promoter -10 and -35 sequences

The sigma sub unit of e. Coli Holo RNA polymerase is important for what function of the enzyme?

recognition of the promoter at the -10 and -35 sequences

rRNA

ribosomal RNA; makes up the ribosomes

Which of the following help(s) to hold the DNA strands apart while they are being replicated?

single-strand DNA binding proteins

Rank, from low to high, the pH of blood, stomach acid, and urine.

stomach acid, urine, blood

The leading and the lagging strands differ in that

the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction

In the structural organization of many eukaryotic genes, individual exons may be related to which of the following?

the various domains or regions of the polypeptide product

What is the purpose of telomeres?

to protect the ends of linear chromosomes

tRNA

transfer RNA- transfers amino acids

3' UTR

untranslated region at the 3' end of the RNA

5' UTR

untranslated region at the 5' end of the rNA