Download BIO 210: Module 8 Exam Questions with Verified Answers - Genetics and Molecular Biology and more Exams Biology in PDF only on Docsity!
BIO 210: MODULE 8 EXAM QUESTIONS WITH VERIFIED ANSWERS
“What is genetics? - CORRECT ANSWER Study of genes"
"What are genes? - CORRECT ANSWER Segment of DNA coding for a functional product"
"What is a chromosome? - CORRECT ANSWER Structure of DNA coding for a functional
product"
"What is a genome? - CORRECT ANSWER All the genetic information in a cell"
"What is genomics? - CORRECT ANSWER The molecular study of genomes"
"What is genotype? - CORRECT ANSWER The genes of an organism"
"What is a phenotype? - CORRECT ANSWER Expression of the genes"
"The duplication of a cell's DNA is called - CORRECT ANSWER Replication"
"The DNA molecule is composed of building blocks called - CORRECT ANSWER nucleotides"
"The polymer of DNA is - CORRECT ANSWER Nucleic acid"
"What is the complementary sequence for a segment of DNA with the sequence GTCCAC? -
CORRECT ANSWER C, A, G, G, T,G"
"Do both strands of the parental double helix act as a template for DNA replication? - CORRECT
ANSWER Yes"
"What does it mean that DNA replication is semi-conservative? - CORRECT ANSWER Each
parental strand pairs up with a new strand of DNA" "If you could add a colored label to each strand of a DNA molecule then then follow the colored label in the DNA molecules that result from replication of the original DNA, in the two new
molecules you would see: - CORRECT ANSWER B"
"What is the role of the helicase? - CORRECT ANSWER unwinds the DNA"
"Why is the lagging strand made in small fragments? - CORRECT ANSWER Lagging strand is
made in small fragments because DNA polymerase can only add onto the 3' end and this is going away from the replication fork" "True or false. DNA replication proceeds in only one direction around the bacterial chromosome.
Explain your answer. - CORRECT ANSWER False, DNA replication goes in both directions
around the bacteria chromosome."
"Bacteria replicate DNA using (which Greek symbol) replication? - CORRECT ANSWER Θ
(theta)"
"What is the code of DNA specified in? - CORRECT ANSWER The sequence of nucleotides
along the chain"
"What is the difference between genotype and phenotype? - CORRECT ANSWER -Genotype:
encoded (carried in its sequence of bases
- Phenotype: physical consequence of the proteins that are expressed from its genotype"
"What is transcription? - CORRECT ANSWER the synthesis of RNA from a DNA template
(copying DNA strand onto RNA)"
"How many nucleotides are used in a codon? - CORRECT ANSWER 3"
"What molecule takes the information encoded in the DNA and transfer the information to the
cytoplasm? - CORRECT ANSWER mRNA"
"In eukaryotic cells, which of the following processes occur in the nucleus: DNA replication,
transcription, and/or translation? - CORRECT ANSWER Transcription and DNA replication"
"What is the name of the site on DNA where RNA polymerase binds to initiate transcription? -
CORRECT ANSWER promoter"
"What do we call the genes that are only expressed as needed? - CORRECT ANSWER adaptive
genes" "What 3 genes are controlled by the lac operon (example, lac Z)? What protein does each gene
produce and what is each enzyme used for to metabolize lactose? - CORRECT ANSWER -Lac z
--> Beta-galactosidase- enzyme used to hydrolyze lactose -Lac y --> permease- lactose membrane transporter Lac A --> transacetylase- modify toxic galactosides" "True or False. For the lac operon, each gene is under the control of its own promotor (meaning
one promoter for one gene). Explain your answer - CORRECT ANSWER False, lac Z, lac Y, lac A
are all under the control of a single promoter --> either all on or off"
"What is the lac I gene used for? Is the lac I gene a constitutive or an induced gene? - CORRECT
ANSWER -Lac repressor binds to operator --> turns off transcription of the lac operon.
- Lac I: lac repressor -> always transcribed = constitutive" "Explain how the lac operon gets activated and begins transcription. What is the inducer and how
does it induce transcription? - CORRECT ANSWER If lactose is present --> produce allolactose
(inducer) --> bind to repressor protein (lac I), causing the repressor to change shape and it no longer binds to the operator, RNA polymerase can bind promoter to turn on transcriptipn"
"What is the name for proteins that inhibit transcription? - CORRECT ANSWER Repressor"
"Under what conditions would the trp operon be off? Under what conditions would the trp
operon be on? - CORRECT ANSWER -On= low trp concentration --> make trp
- Off = high trp concentrations --> don't need to make trp" "Explain what happens in a cell when tryptophan levels are high. How does this regulate the trp
operon? - CORRECT ANSWER - trp operon produces enzymes to synthesize trp
- when [ trp] increase --> transcription is off --> trp binds to the repressor protein and activates it --> repressor binds to operator and turns off transcription"
"Compare feedback inhibition and feedback repression. How are they different? - CORRECT
ANSWER Feedback inhibition:
-Affects enzymatic activity (allosteric inhibition)
-Fast-acting -Short-lived effect Feedback repression: -Affects enzymatic production -Slower response time -Effects more enduring"
"True or false. Feedback repression affects the activity of an enzyme. Explain your answer. -
CORRECT ANSWER False, feedback inhibition affects enzymatic activity, whereas feedback
repression affects enzymatic production."
"When a mistake is made in DNA replication and not corrected, what is this referred to as? -
CORRECT ANSWER mutation"
"What do you call the mutations that change the DNA sequence by one or a few nucleotides? -
CORRECT ANSWER point mutations"
"What do you call a mutation that does not change the number of nucleotides? - CORRECT
ANSWER base-pair substitution"
"What would happen to a protein if a mutation prematurely added a stop codon in the mRNA?
What do we call this type of mutation? - CORRECT ANSWER - shortened or truncated protein
--> drastically change protein
"What do we call a mutation that does NOT change the amino acid? - CORRECT ANSWER
silent"
"What is a missense mutation? - CORRECT ANSWER change one amino acid"
"How are vertical gene transfer and horizontal gene transfer different? - CORRECT ANSWER -
Vertical gene transfer: Occurs during reproduction between generations of cells. -Horizontal gene transfer: The transfer of genes between cells of the same generation."
"What are the three types of horizontal gene transfer? - CORRECT ANSWER 1. transformation
- transduction
- conjugation"
"What are the three types of plasmids? Explain each type. - CORRECT ANSWER •Conjugative
plasmid: Carries genes for sex pili and transfer of the plasmid •Dissimilation plasmids: Encode enzymes for catabolism of unusual compounds •R factors: Encode antibiotic, heavy metal, or cellular toxins resistance"
"What are the 2 groups of genes that can be found on a R factor plasmid? - CORRECT ANSWER
-Resistance transfer factor (RTF) -r-determinant"
"What are transposons? - CORRECT ANSWER - small DNA segments
- "jumping agents"
- can move on same chromosome or to different chromosomes or plasmids -may or may not replicate before moving -prokaryotes, eukaryotes, virues, can jump between unrelated species (by plasmids or viruses)"
A ligamentous connection, such as that between the bones of the lower leg, is called a -
CORRECT ANSWER syndesmosis"
"Movement of a limb towards the midline of the body is called - CORRECT ANSWER
adduction"
"A synovial joint is an example of a(n) - CORRECT ANSWER diarthrosis"
"A twisting motion of the foot that turns the sole inward is called - CORRECT ANSWER
inversion"
"An immovable joint is a(n) - CORRECT ANSWER synarthrosis"
"What is the function of bursae? - CORRECT ANSWER to reduce friction"
"Decreasing the angle between bones is called - CORRECT ANSWER flexion"
"In a uniaxial articulation - CORRECT ANSWER movement can occur in only one axis"
"Osteoarthritis is considered - CORRECT ANSWER a degenerative joint disease, or "wear-and-
tear arthritis""
"The joint at the base of the thumb is an example of a(n) __________ joint. - CORRECT
ANSWER saddle"
"The joint that permits the greatest range of mobility of any joint in the body is the __________
joint. - CORRECT ANSWER shoulder"
"Which ligaments prevent backward displacement of the tibia or forward sliding of the femur? -
CORRECT ANSWER "
"Which of the following is NOT a function of synovial fluid? - CORRECT ANSWER increase of
osmotic pressure within joint"
"The epiphyseal growth plate is an example of a(n) - CORRECT ANSWER synchondrosis"
"Why are there NO blood vessels inside the joint cavity of synovial joints? - CORRECT ANSWER
Movement would damage the delicate blood vessels."
"Which of the following is NOT a synovial joint? - CORRECT ANSWER sternocostal joint"
"What motion is ONLY possible at the thumb? - CORRECT ANSWER opposition"
"All of the following are structural classifications of joints EXCEPT - CORRECT ANSWER
osseous"
"Which of the following joints has/have a joint cavity? - CORRECT ANSWER the knee"
"Weeping lubrication is caused by the __________ in a synovial joint. - CORRECT ANSWER
synovial fluid"
"Which of the following factors would NOT provide stability to a synovial joint? - CORRECT
ANSWER the presence of tendon sheaths and bursae"
"What percent of their length can ligaments be stretched before they snap? - CORRECT
ANSWER 6%"
"What type of motion occurs at a synovial joint when one flat bone surface slips over another
without appreciable angulation or rotation? - CORRECT ANSWER gliding of ribs on the
articular facet of a vertebra"
"What type of bond holds complementary bases together of adjacent strands of DNA? -
CORRECT ANSWER Hydrogen bond"
"What type of bond holds together the backbone on a DNA strand (joining the sugar and
phosphate together of adjoining nucleotides)? - CORRECT ANSWER Covalent bond"
"What are the products of the replication of one DNA molecule? - CORRECT ANSWER 2
identical DNA molecules that have one parental strand paired with one newly synthesized strand"
"What are origins of replications? - CORRECT ANSWER Specific DNA sequences that are
recognized by specific proteins and DNA is unwound at these sites."
"What is the function of the origins of replication in DNA replication? - CORRECT ANSWER
They are used to initiate DNA replication"
"True or false. Multiple replication forks are possible on a chromosome. - CORRECT ANSWER
True, DNA replication is going to go in both direction in which makes multiple replication forks"
"What is the role of DNA polymerase? - CORRECT ANSWER Adds nucleotides to a growing
chain (only goes 5' to 3'). Also helps with "Editing" out mistakes; they remove mismatched nucleotides and replace them with the proper match"
"What is the role of DNA ligase? - CORRECT ANSWER joins small fragments into a continuous
chain" "DNA polymerase only adds nucleotides to which end of the growing nucleotide chain (5' or 3')?
CORRECT ANSWER 3'"
"What is the difference between the way the leading and the lagging strange are produced in DNA
replication? Which one produces Okazaki fragments? - CORRECT ANSWER Leading strand is
made in one continuous strand while the lagging strand is made in pieces called Okazaki fragments" "What is function of DNA gyrase? Is it used for replication of prokaryotic cells, eukaryotic cells, or
both? - CORRECT ANSWER -DNA gyrase- separate the two circular DNA (and relaxes
supercoiling). -Prokaryotic cells" "True or false. Both strands of DNA are used as a template for transcription. Explain your answer.
- CORRECT ANSWER False, only one strand of DNA used as a template for transcription because we are making a single stranded mRNA"
"What does it mean to say that the genetic code has redundancy and is unambiguous? -
CORRECT ANSWER -Redundancy: multiple codons could mean the same amino acid
-Unambiguous: any codon for one amino acid does not code for any other amino acid" "How is the process of protein production different in prokaryotic and eukaryotic cells? (hint:
think of how the cell structure may influence these processes)? - CORRECT ANSWER -
Eukaryotic cells --> transcription occurring in the nucleus but translation occurs in the cytoplasm -Prokaryotic cells --> transcription and translation occurring in the cytoplasm"
"What are the 3 stages in transcription and what happens in each stage? - CORRECT ANSWER
- Initiation: RNA polymerase is going to bind to the promoter (specific DNA sequence) where transcription is initiated
- Elongation: RNA polymerase reads DNA strand and it's going to synthesize a newly made mRNA, adding to the three prime and RNA polymerase can only add nucleotides to the three prime just like DNA polymerase can only add to 3' end. (Any elongation, RNA polymerase move along the DNA, reads DNA sequence, and synthesize a new strand of mRNA).
- Termination: transcription terminates when RNA polymerase reaches a sequence called the terminator and falls off the DNA"
"What are the 3 stages in translation and what occurs in each stage? - CORRECT ANSWER 1.
Initiation: mRNA binds to a small ribosomal subunit, and the first tRNA bind to mRNA at the start codon
- the start codon reads AUG and codes for methionine
- the first tRNA has the anticodon UAC
- A large ribosomal subunit joins the small subunit, allowing the ribosome to function
- Elongation: addition of amino acids to the growing polypeptide chain
- links amino acids together via peptide bonds
- Termination: elongation halts a "stop" codon
- No tRNA binds, instead a release of the last tRNA from the ribosome Ribosomal subunits separate and polypeptide is released" "For adaptive genes, what kind of genes are influenced by substrate concentration, are used to conserve energy, and the default position is OFF? What is an example of this kind of regulation
and what is the goal of those genes? - CORRECT ANSWER - inducible genes
-lac operon --> produces enzymes to metabolize lactose --> only on when lactose is present" "In bacteria, what name is given to a cluster of genes with related functions, along with their
control sequences? - CORRECT ANSWER operon"
"In bacteria, what is the name for the DNA segment that is the regulatory "switch", positioned
within the promoter? - CORRECT ANSWER operator"
