Essential Cell Biology Chapter 9
True or false: genes and genomes cannot evolve - ANS-false. genes and genomes are
constantly evolving
What are the main ways that mutants genes can evolve? - ANS-a mutation in a regulatory
region, gene duplication and divergence, exon shuffling, transposition, horizontal transfer
what external forces and cause mutation? - ANS-radiation, x-rays, carcinogens
what does mutation in a gene lead to? - ANS-the formation of a new allele
why is gene duplication so important to evolution? - ANS-typically gene duplication occurs
during crossing over, resulting in two of the same genes in one cell. The cell can then make the
functional protein from one gene and the other gene can mutate to develop into a new allele for
the gene. This forms gene families.
What is the typical result of mutation? - ANS-nothing. typically proteins happen in non important
regions or in the wobble space
what can mutations cause? - ANS-problems for the cell, a harmful change, a beneficial change,
or a change which is not helpful or harmful
What is the significance of mutation on one area compared to another? - ANS-some regions are
required for life and a large mutation would be lethal. This is the "highly conserved" region of the
genome. Some mutations do not effect survival, such as hair or eye color.
What is a point mutation? - ANS-a mutation which changes only one nucleotide base.
When do point mutations usually occur? - ANS-during DNA replication or repair.
What is the consistent rate of mutation for a cell? How does the number of mutations get
increase? - ANS-around 3 per cell, this can be increased by the presence of mutagens
What are examples of mutagens? - ANS-radiation, DNA brinding/ reactive, pro-oxidants, viruses
What is used to study background mutation rates? - ANS-bacteria, generally e. coli
What is lactose tolerance? - ANS-a beneficial mutation which allows humans to drink milk after
weaning. There is evidence that this comes from two independent mutations in human history.
True or false: genes and genomes cannot evolve - ANS-false. genes and genomes are
constantly evolving
What are the main ways that mutants genes can evolve? - ANS-a mutation in a regulatory
region, gene duplication and divergence, exon shuffling, transposition, horizontal transfer
what external forces and cause mutation? - ANS-radiation, x-rays, carcinogens
what does mutation in a gene lead to? - ANS-the formation of a new allele
why is gene duplication so important to evolution? - ANS-typically gene duplication occurs
during crossing over, resulting in two of the same genes in one cell. The cell can then make the
functional protein from one gene and the other gene can mutate to develop into a new allele for
the gene. This forms gene families.
What is the typical result of mutation? - ANS-nothing. typically proteins happen in non important
regions or in the wobble space
what can mutations cause? - ANS-problems for the cell, a harmful change, a beneficial change,
or a change which is not helpful or harmful
What is the significance of mutation on one area compared to another? - ANS-some regions are
required for life and a large mutation would be lethal. This is the "highly conserved" region of the
genome. Some mutations do not effect survival, such as hair or eye color.
What is a point mutation? - ANS-a mutation which changes only one nucleotide base.
When do point mutations usually occur? - ANS-during DNA replication or repair.
What is the consistent rate of mutation for a cell? How does the number of mutations get
increase? - ANS-around 3 per cell, this can be increased by the presence of mutagens
What are examples of mutagens? - ANS-radiation, DNA brinding/ reactive, pro-oxidants, viruses
What is used to study background mutation rates? - ANS-bacteria, generally e. coli
What is lactose tolerance? - ANS-a beneficial mutation which allows humans to drink milk after
weaning. There is evidence that this comes from two independent mutations in human history.
