BSC Chapter 4 Online Questions
Define mutation. Explain why some mutations are harmless and others can be lethal.
A Mutation is a change in DNA structure due to replication errors or environmental factors. Some mutations can kill the cell, turn it cancerous, or cause genetic defects in future generations. Some Mutations cause no ill effect.
As helicase unwinds the DNA molecule, the separated strands are kept apart by DNA polymerase. (t/f)
FALSE
The codon of tRNA is complementary to the anticodon of mRNA. (T/F)
FALSE
The main difference between traditional DNA fingerprinting and the method that has superceded it is that the newer method does not contain variable number of tandem repeat sequences - or VNTRs. (T/F)
FALSE
Unwinding of the DNA during transcription is the result of the activity of a helicase enzyme downstream of the RNA polymerase. (t/f)
FALSE
Summarize the processing of a protein from the time a ribosome finishes its work to the time a protein is secreted from the cell. What roles do the endoplasmic reticulum and Golgi complex play in this?
First protein is form by the ribosomes on the rough ER. Then it is packaged into the transport vesicle. The transport vesicle fuses into clusters that drop into the Golgi Complex. In the Golgi Complex the proteins structure is modified and then the Vesicle that had the protein in it is now formed. In The Golgi Complex the protein structure is modified and formed.
Which of the following occurs first in transcription?
Formation of a holoenzyme
DNA is unwound by
helicase
The mitotic spindle fibers attach to chromosomes via special structures termed
kinteochores
The transcription enzyme first attaches to the ________ of the gene.
promoter
A version of a trait that requires a homozygous genotype for expression is called a
recessive allele.
Translation is characterized by...
the blueprint of the RNA molecule used to bind amino acids together to form proteins.
Which of the following occurs as the ribosome shifts down the mRNA by a distance of one codon?
the tRNA that was in the A site moves into the P site
The cell cycle is regulated by checkpoints during the _______ phases.
G1, G2, Metaphase
Explain why DNA replication is called semiconservative.
It's called semi-conservative because each of the new DNA molecules has "conserved" (kept) one of the two original DNA strands ("semi" because only 1 was kept, the other was new)
Summarize the structural and functional differences between DNA and RNA.
RNA has the sugar ribose, it is single stranded and has the base Uracil instead of Thymine. DNA has the sugar deoxyribose, it is double stranded and has the Base Thymine not Uracil.
Describe the roles of RNA polymerase, ribosomes, and tRNA in producing a protein.
RNA: The messanger that travels from the transcribed DNA to the Ribosomes where the Proteins are put together. tRNA: To carry the correct amino acid to the mRNA on the ribosome during protein synthesis. Ribosomes: Ribosomes are the place where Protein Synthesis takes place.
New amino acids (other than the initial f-Met) enter at which site?
Site A
A mutation that changes a single nucleotide can result in a different amino acid being added into a protein. (T/F)
TRUE
DNA fingerprinting is a method of identification based on the whirls and loops of the epidermal ridges. (T/F)
TRUE
Define gene, genetic code, codon, and anticodon.
The Genetic Code is a system that enables these A,C,T,G nucleotides to code for the amino acid sequence of all proteins. A gene is the physical and functional unit of heredity. A Codon is the 3 base sequence in mRNA. An Anticodon is one end of the L that includes three nucleotides.
DNA polymerase can add nucleotides to
a free 3' OH end of a growing DNA chain.
State at least three reasons why a person's phenotype can't always be determined from the genotype.
1) An individual's phenotype can't be used to determine its genotype because the genotype determines the phenotype. 2) The genes carry much more information then is shown by the phenotype. 3) Some genotypes result in the same phenotype.
