BIO 181 Exam 4

Which of the following base pairs would be targeted and repaired by a mismatch repair system?

A-G

What type of regulatory transcription factor binds DNA in order to increases the transcription of a gene?

An activator exerting positive control

A cell secretes a growth factor that binds to receptors on its own membrane preventing it from proliferating. This is an example of

Autocrine signaling

Based on the gene and protein sequences that follow, what type of mutation has occurred and what is the effect on the polypeptide? Normal gene: ATG GCC GGC CCG AAA GAG ACC Mutated gene: ATG GCC GGC ACC GAA AGA GAC C Normal protein: Met-Ala-Gly-Pro-Lys-Glu-Thr Mutated protein: Met-Ala-Gly-Thr-Glu-Arg-Asp

Base addition-frameshift

The likely outcome from a mutation in the lacO site (lac Operator) of the lac operon would be

Binding of a repressor protein could be hindered

Which is FALSE when comparing RNA and DNA?

Both are composed of the same types of nucleotides.

Which relationship about nucleotide composition in DNA is correct?

C+A=G+T

You are given two nucleic acids, one RNA and the other DNA. What are the main features to determine which is the DNA?

DNA will have thymine instead of uracil in its nitrogenous bases. DNA will have a double-stranded structure.

Which factors are utilized by the cell to recognize the stop codon and disassemble the translation machinery?

Release factors

An activator is to an enhanced as a _______ is to a silencer

Repressor

An ________ operon is one whose transcription is increased by effector molecules.

Inducible

If a cell's splicesomes were mutated so they no longer functioned normally, what consequences would result?

Introns would remain in the mature mRNA.

A dehydration reaction

Is used to form polymers

The amino acids of a growing polypeptide chain are held together by what kind of bond during the elongation stage of translation?

Peptide

What type of bonds form from the unequal sharing of electron?

Polar covalent

Water held behind a dam would best reflect

Potential energy

Water diffuses through certain organs such as the kidneys and bladder much faster than would occur by passive diffusion through a lipid bilayer alone. What accounts for this more rapid rate of water transport in these organs?

Presence of aquaporin channels for facilitated diffusion of water.

Which sequence of events CORRECTLY describes the initiation and elongation steps of translation in prokaryotic cells? (1) Initiator tRNA binds start codon on mRNA (2) Small ribosomal subunit binds to mRNA (3) Large ribosomal subunits binds (4) tRNA entry and peptidyl transfer reaction (5) Translocation of ribosome and release of tRNA

2,1,3,4,5

A DNA specimen that contains 30% guanine has ________ thymine.

20%

How many nucleotides are contained in a single codon?

3

If a DNA template strand has a sequence of 3′ TACAATGTAGCC 5′, then the RNA produced from it will be which sequence?

5′AUGUUACAUCGG3'

Which statement about RNA processing in eukaryotes is INCORRECT?

The excision of introns from pre-mRNA is the only modification required to produce a mature mRNA.

What would result from a single nucleotide deletion (point mutation) within the coding sequence of a structural gene?

a frameshift mutation, producing a completely different amino acid sequence.

If orange juice has a pH of 4 then it can be described as

an acidic solution

The process of breaking glycogen down to glucose is an example of

catabolism

Where does glycolysis take place?

cytosol

When one oxygen atom shares two pairs of electrons with another oxygen atom, O2 is formed via a(n)

double covalent bond

A community of organisms interacting with their physical environment is an

ecosystem

The organelle responsible for the biosynthesis of proteins that are destined for secretion by the cell is the

endoplasmic reticulum

Following a meal, glucose must move from the gut lumen where there is a high glucose concentration into the intestinal cell where there is a relatively low level of glucose. This movement is called

facilitated diffusion

An organized unit of DNA sequences that enables a segment of DNA to be transcribed into RNA and ultimately results in the formation of a functional product is called a

gene

A cells ability to control their level of gene expression is called

gene regulation

Which of these organisms consume organic molecules to live?

heterotrophs

DNA methylation

inhibits transcription

Intervening sequences that are transcribed, but not translated into protein are called

introns

Assume each of the following letters represents an amino acid. What type of gene mutation occurred to produce the following protein sequence? Normal: JAYBIRDCATPAW Mutated: JAYBIRDBATPAW

missense

A researcher determined that a strain of E. coli is producing a shortened version of a protein required for glucose metabolism. What type of mutation could be responsible for this shorter than normal protein?

nonsense mutation

The building blocks of DNA are

nucleotides

The nucleotides within DNA are composed of a

phosphate group, deoxyribose sugar, and nitrogenous base

In a eukaryotic cell, the direct product of transcription is

pre-mRNA

Transcription begins near a site in the DNA called the

promoter

The macromolecule composed of amino acids is a

protein

During glycolysis, glucose is broken down into

pyruvate

Glycogen is to animal cells as _______ is to plant cells.

starch

The ATP made during glycolysis is generated by

substrate-level phosphorylation

The process that produces mRNA from DNA is called

transcription

The core promoter in eukaryotes is usually composed of which two features?

transcriptional start site and TATA box

Which of the following is an overgrowth of cells that serves no useful purpose?

tumor

True or false: A single gene always encodes for a protein

False

True or false: A strand of DNA is composed of nucleotide bases, sulfate groups, and sugars.

False

True or false: If there is 28% adenine, then there must be 28% cytosine for the DNA composition of a particular organism.

False

The conversion of pyruvate to acetyl CoA is irreversible. Predict what would happen to fatty acids as a result of this.

Fatty acids cannot be converted into carbohydrates.

Identify a reactant in the light reaction of photosynthesis.

H2O

Whether the external temperature is hot or cold, birds maintain an internal body temperature of approximately 40°C. This is an example of

Homeostasis

True or false: An mRNA molecule, which contains the information to make a polypeptide, is constructed using a DNA template.

True

True or false: Barr Bodies are a diagnostic feature of X inactivation

True

True or false: Both eukaryotes and prokaryotes require a promoter region of gene transcription

True

True or false: The termination of translation occurs when a release factor recognizes the stop codon.

True

The process through which cells can detect and respond to signals in their extracellular environment is called

Cell communication

The best way to distinguish an epigenetic effect from other types of gene regulation would be to

Confirm that the change in gene expression is passed from cell to cell but does not involve a change in the DNA sequence.

Genes expressed at relatively constant levels in tissues regardless of variations in the animal's condition are called

Constitutive genes

Eukaryotic DNA methylation occurs on which base?

Cytosine

A major difference in gene regulation between prokaryotes and eukaryotes is that

Eukaryotic genes are arranged individually, while prokaryotic genes are grouped into operons

Which of the following statements is TRUE?

Many active genes are found in euchromatin, because proteins involved in transcription can easily access these regions of DNA

Cyanide binds and impairs one of the molecules involved in the synthesis of ATP. The target organelle for cyanide must be

Mitochondria

All of the following are a form of potential energy that can be used by a cell except

Nitrogen

Subunits (monomers) sometimes build up to form a macromolecule (polymer). Which of the listed molecules is NOT a monomer of a polymer?

Steroid

The ultimate source of energy for reactions in plants is ________

The sun

When considering nomenclature for scientific names, what is the difference between the two primates, Homo sapiens and homo erectus

They are animals of a different species.

Which products of nonstructural genes are never translated?

Transfer RNA and ribosomal RNA