AP Bio - mutations and genes

changes in the genetic material of a cell, which can alter phenotypes

mutations

primary source of genetic variation

mutations

large scale mutations

chromosomal changes

small scale mutations

nucleotide substitutions, insertions, or deletions

changes in a single nucleotide pair of a gene

point mutations

the replacement of one nucleotide and its partner w/ another pair of nucleotides

substitution

still codes for the same amino acid

• redundancy

silent

change results in a different amino acid

missense

change results in a STOP codon

nonsense

when the reading frame of genetic information is altered

• small scale mutation

frameshift mutation

insertions and deletions have:

• small scale mutations

disastrous effects to resulting proteins

when chromosomes do not separate properly in meiosis

ex: down syndrome

nondisjunction

a segment of one chromosome moves to another

translocation

a segment is reversed

translocation

a segment is repeated

duplication

a segment is lost

deletion

any time __________ occur, they are subject to natural selection

• genetic changes can sometimes enhance the survival and reproduction of an organism

mutations

prokaryotes can exchange genetic material through:

horizontal gene transfer

if there is a mutation beneficial to the survival and reproduction of a prokaryote, it can be:

transferred

uptaking of DNA from the environment

transformation

viral transmission of genetic material

transduction

cell to cell transfer of DNA

conjugation

movement of DNA segments w/in and between DNA molecules

transposition

both DNA and RNA can be manipulated through

genetic engineering

a technique used to separate DNA fragments by size

• DNA is loaded into wells on one end of a gel and an electric current is applied

  • DNA fragments are positively charged

gel electrophoresis

a method used in molecular biology to make several copies of a DNA segment

• segments of DNA are amplified

• results can be analyzed using gel electrophoresis

PCR

a type of protein found in chromosomes

histones

a group of histone proteins with nucleotides wrapped around it, fundamental unit of chromatin

nucleosomes

DNA is _______ charged and histones are _________ charged

negatively, positively

chromatin must be _________ to expose the promoter so RNA polymerase can bind to it

decondensed

promoted decondensed chromatin in histones

• active transcription

acetylation

• promotes condensed chromatin

  • associated with transcriptional repression (most of the time)HA

methylation

histone acetyltransferases

HATs

histone deacetylases

HDACs

cause chromatin to decondense

HATs

cause chromatin to condense

HDACs

a group of proteins that use energy from ATP hydrolysis to shift nucleosomes on DNA so as to expose or hide DNA sequences from transcription factors

chromatin remodeling complexes