Unit 6, Topic 7: Mutations Flashcards
a permanent change in a DNA sequence
Mutations
underlying genetic makeup, consisting of both physically visible and non-expressed alleles, of an organism
Genotype
observable traits expressed by an organism
Phenotype
failure of synapsed homologs to completely separate and migrate to separate poles during the first cell division of meiosis
Nondisjunction
process by which one segment of a chromosome dissociates and reattaches to a different, nonhomologous chromosome
Translocation
detachment, 180° rotation, and reinsertion of a chromosome arm
Inversion
a base pair is removed from the DNA sequence
Deletion
transfer of genes between unrelated species
Horizontal gene transfer
process in which external DNA is taken up by a cell
Transformation
in prokaryotes: the cell takes in DNA shed by other prokaryotes
process by which prokaryotes move DNA from one individual to another using a pilus
Conjugation
genes are transferred from one organism to another through copying and inserting process
Transposition
mutation that affects a single base
Point mutation
multiple copies of genes
Duplication
process by which a bacteriophage moves DNA from one prokaryote to another
Transduction
when pyrimidines and purines replace each other
Substitution
How can mutations lead to natural selection?
They can lead to developments of new traits that help an organism survive
Are substitutions are small or large scale mutations?
small
Differentiate between silent, missense, and nonsense mutations. Predict which would be most detrimental and why?
nonsense because it can prematurely stop translation which can prevent the formation of the correct protein
Mutations can be detrimental, beneficial, or neutral. Give an example of a mutation that is detrimental and an example where it is beneficial.
Detrimental: a mutation that causes rapid weight gain
Beneficial: a mutation that gives longer claws to cats
Neutral: a mutation that doesn’t affect the phenotype of an organism
If one bacterial cell has a gene that is promoting its survival, explain how other bacterial cells can benefit from it.
that one cell can reproduce with the others and create more bacterial cells that will have that same gene
Describe the mutation that causes cystic fibrosis.
Deletion of phenylalanine on amino acid 508
change in an organism’s genotype can cause a change in the organism’s (blank).
phenotype
What does it mean if a gene/trait is “evolutionarily conserved”?
A gene that has remained essentially unchanged throughout evolution
Describe transformation. Are all bacteria competent?
The prerequisite for bacteria to undergo transformation is its ability to take up free, extracellular genetic material
Describe the process of conjugation
the process by which one bacterium transfers genetic material to another through direct contact
Describe the process of transduction
A bacteriophage passes DNA from one bacteria cell to another (transfer of DNA from one cell to another via a viral vector)
What are the two reproductive cycles of bacteriophages? Describe each.
lytic (virulent) or lysogenic (temperate). Lytic phages take over the machinery of the cell to make phage components. They then destroy, or lyse, the cell, releasing new phage particles Bacteriophages: a virus that parasitizes a bacterium by infecting it and reproducing inside it
