questions and answers graded A+
What is a genome? - answercomplete set of genetic info of a cell; includes plasmids
and chromosome
How do the genomes of eukaryotic, prokaryotic microorganisms differ? -
answereukaryotic genome: linear, double strand DNA, many chromosomes, nucleus,
organelle chromosomes Prokaryotic genome: circular, double strand DNA, single
chromosome, nucleoid, plasmids
How do genomes of viruses/bacteriophages differ from others? - answersome viruses
have RNA genome, DNA or RNA, linear or circular, double stranded or single strand,
single or many segments
How does the Central Dogma state how information transmitted? What is a viral
exception to this? - answerDNA -> RNA -> Protein Retroviruses are a viral exception to
the Central Dogma as their information is transmitted from RNA to DNA
What does semi-conservative replication mean? - answereach of the two molecules
created contains one of the original strands paired with a newly synthesized strand.
How does the arrangement of DNA in eukaryotes differ from that in prokaryotes? -
answerDNA in eukaryotes is larger and arranged on chromosomes in the nucleus.
Prokaryotic DNA is circular and compacted, most is coding DNA
What are the differences between DNA and RNA? - answerDNA: double stranded helix,
deoxyribose, phosphate, Thymine RNA: single stranded linear, ribose, phosphate,
Uracil
How is information transmitted in replication? - answerDNA is unzipped and goes both
directions, creating a replication fork. DNA polymerase synthesize DNA in the 5' to 3'
direction, using one parent strand as a template to make the complement. DNA
polymerase adds nucleotides to the 3' end.
How is information transmitted in transcription? - answerRNA polymerase synthesizes
RNA (mRNA) from a DNA template, adding nucleotides to the 3' end. The RNA
sequence is complementary and antiparallel to the DNA template strand.
How is information transmitted in translation? - answermRNA contains encoded
instructions for synthesis of specific protein. tRNA interprets genetic code of mRNA
codons and each tRNA carries specific amino acid dictated by its anticodon. the codon
sequence in mRNA determines sequence of aa in protein, according to genetic code
, What enzymes are used in replication, transcription, and translation? - answerDNA
helicase, DNA ligase, DNA polymerase, RNA polymerase, DNA primase, DNA gyrase
Different types of RNA and significance of each - answermRNA: temporary copy of info
in DNA, carries contains genetic info decoded in translation in order for specific protein
synthesis. Codon sequence in mRNA determines amino acid sequence in protein
tRNA: carries amino acid used in translation, dictated by its anticodon. recgonizes start
and stop codon.
rRNA: ribosomal RNA
What does it mean that the genetic code is degenerate (redundant)? - answermore than
one codon can code for the same amino acid
Which base is unique to DNA? - answerThymine
Which base is unique to RNA? - answerUracil
How many nucleotides are used to encode an amino acid? - answer3
What is a polycistronic message? Are they found in prokaryotes or eukaryotes? -
answermRNA molecule that carries info for multiple genes. found in prokaryotes
What is an operator? What binds to this element? - answerspecific DNA sequence/
region located immediately downstream of a promoter to which a repressor can bind
(block transcription)
What is a promoter? What binds to this element - answernucleotide sequence that RNA
polymerase binds to initiate transcription
What is the difference between an inducible system and a repressible system? -
answerinducible system is not routinely sythesized, but can be turned on when needed.
repressible system is routinely synthesized but can be turned off.
Under what conditions will the lac operon be expressed? - answerwhen high amount of
lactose is present, and absent / little amount of glucose present
Under what conditions will the lac operon be repressed? - answerwhenever there is
enough glucose present no matter amount of lactose, or when there is no glucose or
lactose
What would happen to the transcription of the lac operon if the gene for the repressor
protein was mutated (non-functional)? - answerif the repressor protein was mutated, it
would not be able to bind to the operator to block initiation of transcription, so the lac
operon would always be expressed