Bio Unit 5
True or false A purine to purine, or a pyrimidine to pyrimidine change is called Transition
True
True or false Most mutations are neither harmful nor helpful
True
True or false Mutations are best described as changes in DNA or RNA
True
Mutations increase genetic ______ and the potential for individuals to differ.
Variation
Examples of potentially dangerous mutagens include which of the following? (1) cigarette smoke (2) chemicals in processed meats (3) overexposure to sunlight (4) certain viruses -1 only -1 and 3 -2 and 4 -1, 2, 3, and 4
1, 2, 3, and 4
Examine the following mutation: ACGGGCAAACGATTG to ACGGGCAACGATTG. The mutation is -A frameshift mutation -An insertion of a single nucleotide -A nonsense mutation -A duplication mutation
A frameshift mutation
Distinguish between mutation and mutagen.
A mutation is the base or chromosomal change in the DNA sequence, either spontaneous or induced. A mutagen is the environmental factor that induces a mutation to occur. A mutagen causes mutation.
Types of point mutations include -Missense mutations -Nonsense mutation -Silent mutations -All of the above
All of the above
True or false Single base substitutions are not considered to be mutations
False
Which of the following types of mutations would most likely result in a genetic disorder -Somatic mutation -Silent mutation -Frameshift mutation -All of the above
Frameshirt mutation
Why are mutations essential for evolution to occur?
Mutations are essential for evolution to occur because they increase an organism's chance of surviving and reproducing, so they are likely to become more common over time.
Compare and contrast spontaneous mutations and induced mutations.
Spontaneous mutations occur under natural conditions and are random changes in teh DNA. Induced mutations are changes in DNA caused by mutagens. Mutagens are environmental factors that induced a mutation to occur.
Examine the following mutations: AUG-GUC-CCU-AAA to AUG-AGU-CCC-UAA-A. Describe how this mutation affects the encodon amino acid sequence.
The base A was inserted into the mRNA sequence after the first G. This causes a frameshift mutation, where the reading frame is moved over one base. When the reading frame is changed, the following codon sequence shifts and now codes for different amino acids, resulting in a protein that does not function properly or at all.
Assume that a point mutation changes the codon AUU to AUC. Explain why is this a neutral mutation.
This point mutation is a neutral mutation because the codon AUU and AUC both code for the same amino acid, isoleucine. This mutation has no effect on the final polypeptide chain.
True or false Cystic Fibrosis is a genetic disorder
True
True or false The two major categories of mutations are germline mutations and somatic mutations
True
Which of the following statements are correct concerning mutation? -Mutations are essential for evolution to occur -A mutation is change in the sequence of bases in DNA or RNA -Most mutations have no effect on the organism in which they occur -All of the above
all of the above
______ is a disease in which cells grow out of control and form abnormal masses of cells
cancer
Ultraviolet radiation, X-ray radiation, and other chemicals are all: -causes of mutations -used in barbecuing -used in labs -none of these
causes of mutations
True or false Beneficial mutations may become more common through artificial selection
false
A ______ is a disease caused by a mutation in one or a few genes. -evolution -natural selection -genetic disorder -mutagen
genetic disorder
True or false A mutation always causes a mutant phenotype.
False
True or false Somatic mutations occur in gametes
False
______ mutations may become more common through natural selection.
Beneficial
Spontaneous mutations occur due to errors in ______. -telemerase -DNA replication -RNA replication -All of these
DNA replication
A ______ mutation changes the reading frame of the mRNA
Frameshift
Induced mutations are caused by ______.
Mutagens
A ______ mutation codes for the same amino acid.
Silent
Distinguish between silent, missense, and nonsense mutations
Silent, missense, and nonsense mutations are all point mutations. Silent mutations code for the same amino acid and have no effect on the resulting protein.
Types of chromosomal alterations include -Translocation -Frameshift mutations -Point mutations -All of the above
Translocations
Mutations are essential for evolution to occur because they increase ______. -genetic variation -potential for individuals to differ -survivability of the species - all of the above
all of the above
Many mutations cause ______. -cancer -mutagens -chemotherapy -all of the above
cancer
Down Syndrome is due to trisomy of the 21st chromosome caused by: -non-disjunction during egg formation -non-disjunction during sperm formation -addition of the extra chromosome -either A or B
either A or B
Anything in the ______ that can cause a mutation is known as a mutagen.
environment
What is a mutagen? -cancer-causing agent -factor that immediately kills the organism -inherited mutations -environmental factors that cause mutations
environmental factors that cause mutations
Mutations that have neither a negative nor positive effect on the organism is called a ______ mutation.
neutral
