Bio 181 Lab Final Exam with Complete
Solutions
What is complete dominance? Correct Ans-Is a situation where the
phenotypes of a dominant homozygote and a
heterozygote are indistinguishable
What is incomplete dominance? Correct Ans-is a situation where the phenotype of
heterozygotes is intermediate between the phenotypes of individuals homozygous for either
allele
What are the 3 steps of DNA transcription? Correct Ans-Initiation, Elongation, Termination
What happens in each stage of DNA transcription? Correct Ans-Initiation: Transcription
factors and RNA pol bind to DNA. RNA pol begins transcription
Elongation: RNA pol moves down the DNA strand and transcribes, new RNA strand is being
made
Termination: RNA pol reaches a polydenylation signal which release RHO factors that separate
everything
What are the 3 steps of RNA translation? Correct Ans-Initiation, Elongation, Termination
What happens in each stage of RNA translation? Correct Ans-Initiation: RNA binds to small
subunit of Ribosome and the tRNA initiator binds to RNA because of the anticodon being
complementary. Large subunit of Ribosome attatches, the A, E, and P site are made
Elongation: GTP is used to correctly match tRNA to the correct codon. In the P site, the tRNA
holding the polypeptide strand loses strand because a peptide bond forms with the amino acid
from the A site. GTP is used to move tRNA to the right. Process is repeated
Termination: Stop codon allows a release factor to come into the A site. Release factor plus GTP
separates the mRNA, tRNA, ribosome subunits, and release factor
, What are the 6 enzymes involved in DNA replication Correct Ans-Helicase, DNA ligase, DNA
pol III, DNA pol I, Topisomerase, Primase
What are the 3 steps of PCR, their job, and temperature Correct Ans-Denaturation: heat
denaturation (occurs between 95-98 °C) to break hydrogen bonds that bind the DNA double
helix, thus allowing separation of the two strands.
Annealing: cooling the mixture to a lower temperature (55-65 °C) to allow the primers to anneal
(bind) to specific sequences of the template DNA at each end of the target sequence.
Extension: increasing the temperature to 72 °C (optimal temperature for Taq DNA polymerase)
to allow the enzyme to extend the primers to create and add new strands of DNA.
What is taq polyermase? Correct Ans-A heat-stable DNA polymerase that copies DNA at high
temperatures
What is in master mix? Correct Ans-Template DNA - our cheek cells
dNTPs (deoxynucleotides A, C, G, T)
Primers
Taq polymerase
Buffer, Mg2+
What are primers and how do they bind? Correct Ans-A short nucleotide sequence that
serves as a starting molecule upon which DNA is built and synthesized. Bind by complementary
sequences
Solutions
What is complete dominance? Correct Ans-Is a situation where the
phenotypes of a dominant homozygote and a
heterozygote are indistinguishable
What is incomplete dominance? Correct Ans-is a situation where the phenotype of
heterozygotes is intermediate between the phenotypes of individuals homozygous for either
allele
What are the 3 steps of DNA transcription? Correct Ans-Initiation, Elongation, Termination
What happens in each stage of DNA transcription? Correct Ans-Initiation: Transcription
factors and RNA pol bind to DNA. RNA pol begins transcription
Elongation: RNA pol moves down the DNA strand and transcribes, new RNA strand is being
made
Termination: RNA pol reaches a polydenylation signal which release RHO factors that separate
everything
What are the 3 steps of RNA translation? Correct Ans-Initiation, Elongation, Termination
What happens in each stage of RNA translation? Correct Ans-Initiation: RNA binds to small
subunit of Ribosome and the tRNA initiator binds to RNA because of the anticodon being
complementary. Large subunit of Ribosome attatches, the A, E, and P site are made
Elongation: GTP is used to correctly match tRNA to the correct codon. In the P site, the tRNA
holding the polypeptide strand loses strand because a peptide bond forms with the amino acid
from the A site. GTP is used to move tRNA to the right. Process is repeated
Termination: Stop codon allows a release factor to come into the A site. Release factor plus GTP
separates the mRNA, tRNA, ribosome subunits, and release factor
, What are the 6 enzymes involved in DNA replication Correct Ans-Helicase, DNA ligase, DNA
pol III, DNA pol I, Topisomerase, Primase
What are the 3 steps of PCR, their job, and temperature Correct Ans-Denaturation: heat
denaturation (occurs between 95-98 °C) to break hydrogen bonds that bind the DNA double
helix, thus allowing separation of the two strands.
Annealing: cooling the mixture to a lower temperature (55-65 °C) to allow the primers to anneal
(bind) to specific sequences of the template DNA at each end of the target sequence.
Extension: increasing the temperature to 72 °C (optimal temperature for Taq DNA polymerase)
to allow the enzyme to extend the primers to create and add new strands of DNA.
What is taq polyermase? Correct Ans-A heat-stable DNA polymerase that copies DNA at high
temperatures
What is in master mix? Correct Ans-Template DNA - our cheek cells
dNTPs (deoxynucleotides A, C, G, T)
Primers
Taq polymerase
Buffer, Mg2+
What are primers and how do they bind? Correct Ans-A short nucleotide sequence that
serves as a starting molecule upon which DNA is built and synthesized. Bind by complementary
sequences
