40S Unit 3 - Genetic Code Mutations Flashcards
what is a genetic mutation
changes in DNA bases which affect protein synthesis
how do people have genetic mutations
they are born with them but inheritance factors and environmental factors determine whether or not a child will have a genetic mutation
what are environmental factors that cause mutagens called and give examples
they are called mutagens and some examples are:
- UV light
- drugs
- alcohol
- radioactivity
- polychlorinated biphenyls (PCBs)
- persistent organic pollutants (POPs)
what types of DNA code mutations are there
- point mutation
- frameshift mutation
- dimer mutation
what happen during a point mutation
one base is substituted for another in the DNA code resulting in little or no change in amino acids produced
list and explain the 3 types of point mutations
- missense mutation - codes for a different amino acid
- silent mutation - codes for the same amino acid
- nonesense mutation - codes for a stop codon
explain what a frameshift mutation is
the addition and/or deletion of bases occurring at more than one site in the original DNA sequence, resulting in a large number of changes in the amino acids produced
frameshift mutations often result in serious alterations in an organism’s development and appearance
explain what happens during dimer formation mutations
some substances such as mercury, drug, radioactivity or just bad luck can cause a bond to form between adjacent bases making it impossible for mRNA to transcribe the code
what is a chromosome mutation
any change in the structure or arrangement of chromosomes
when do chromosome mutations mostly happen
during the crossing over stage of meiosis
list and explain the types of chromosome mutations
- translocation - the transfer of a piece of one chromosome to another chromosome
- inversion - a region of DNA on the chromosome can flip its orientation with respect to the rest of the chromosome
- deletion- a large section of a chromosome can be deleted resulting in the loss of a number of genes
- duplications - some genes are duplicated and displayed twice on the same chromosome
- non-disjunction - when spindle fibers fail to separate during meiosis resulting in gametes with one extra chromosome and other gametes lacking a chromosome
which chromosome mutation is most likely to cause evolutions of new genes?
duplication
which chromosome mutation causes chronic myelogenous leukemia (CML)
translocation as the chromosome 9 and 22 swap portions of their chromosomes during meiosis
list 3 syndromes that can occur due to non-disjunction
down’s syndrome
turners syndrome
klinefelter syndrome
most chromosome mutations result from _____________________
non-disjunction
how does Down’s Syndrome occur
non-disjunction occurs in chromosome 21 of a human egg cell causing their cells to have 47 chromosomes instead of 46
because of this it is also called Trisomy 21
what happens in Turners Syndrome
all of part of one X chromosome is missing
what happens in Klinefelter Syndrome
an additional X chromosome in males resulting in XXY
state and explain the ways chromosome mutations can be detected
- amniocentesis - karyotype of cells in amniotic fluid
- chorionic villus sampling - testing the uterus lining tissue
- fetal blood sampling
when did the Human Genome Project start and end
began in 1990 and was completed in 2003
what does the Human Genome Project allow u do
the entire human genome is mapped and sequenced and because all life shares the same 4 base DNA codes, it makes it easy to take genes from one species and splice (insert) them into another. it also lets us compare DNA sequences and detect mutations
what is genetic engineering
the alteration of the genetic material of an organism
how can genetically modified organisms be created
- adding a foreign gene
- altering an existing gene
- delete or “turn off” a gene
list the top 10 genetically modified foods
- corn
- soy
- cotton
- papaya
- rice
- canola
- potatoes
- tomatoes
- dairy products
- peas
