point mutations & transposable elements

mutation

change in the sequence of DNA

mutant cells

have mutations

somatic mutations

in body cells and are not passed to offspring

germ-line mutations

are in the gamete cell line and are passed to offspring who then carry the mutation in both somatic and germ line cells

mutation rate

probability of mutation over time

mutation frequency

proportion of mutations

NO (it does through evolution)

does the environment induce changes in a direct way to benefit and individual?

adaptation

phenotypical level --> product of mutation

beneficial mutation

level of DNA --> how DNA is changed

are changes adaptive?

YES;
trait that comes during evolution to enhance survival
at a species level
not acquired during lifetime
ex: chameleons + desert mice

mutation hypothesis

idea that evolution occurred through mutations and natural selection working together; are completely random

adaptation hypothesis

environment CAUSES beneficial adaptations; would expect to see bacteria resistance

mutation hypothesis vs. adaptation hypothesis

experiment:
objective: To determine whether bacterial resistance to a virus (phage) arises due to random mutations or adaptive responses to the virus.
method: They grew multiple separate cultures of bacteria, then exposed each culture to a phage that kills bacteria. They counted the number of resistant colonies in each culture.
result: They observed that the number of resistant colonies varied greatly between different cultures.
conclusion: The high variability in the number of resistant colonies supported the mutation hypothesis. This was because random mutations occurring before exposure would naturally lead to different numbers of resistant individuals in each culture. If the adaptation hypothesis were true, each culture would have had a similar number of resistant colonies.
really important to understand

TRUE

True or False: changing 1 base/base pair can mess everything up; can change protein/enzyme shape and make it not functional

point mutation

change in 1 or a few base pairs

gene mutation

mutation that affects the function of genes (phenotype)

transition mutation

purine to purine or pyrimidine to pyrimidine

transversion mutation

purine to pyrimidine or vice versa

missense mutation

change from one amino acid to another

nonsense mutation

change from an amino acid to a stop codon

neutral mutation

change from an amino acid to another amino acid with similar chemical properties; NOT a BAD mutation; gives insight on individual variation (how people are different)

silent mutation

change in codon such that the same amino acid is specified

frameshift mutation

addition or deletion of one or a few base pairs leads to a change in reading frame; HUGE change made to whole sequence

sickle-cell anemia

point mutation (missense--> amino acid is changed); hemoglobin formed does not have the same properties

forward mutation

changes a wild type gene to a mutant gene

reverse mutation

changes a mutant gene back to, or nearly back to a wild-type gene

true reversion

changes back to wild type

partial reversion

changes to an amino acid that restores partial or full function; might not be the same sequence

suppressor mutation

lessens or eliminates the effects of a mutation at another site but does not reverse the original mutation; DOES NOT FIX DIRECTLY

intragenic suppressor mutation

occurs within the same gene
- change a different nucleotide in the same codon where the original mutation occurred or change a nucleotide in a different codon

intergenic suppressor mutation

occurs in a different gene

mutagenesis

creation of mutations

mutagens

induce mutations

tautomers

rare forms of the normal bases which result in altered H-bonding patterns
(T-G, C-A)
can alter formula + structure
original base pair combos wont be as stable if tautomers are present

additions/deletions

_______/______ of bases can occur spontaneously during replication

false

mutations are neither spontaneous or induced--> environment cannot produce mutations (radiation, etc)