understanding genetic mutations Flashcards
What is a genetic mutation?
-> what are the effects of a genetic mutation? (3 types)
-> what causes a genetic mutation?
Genetic mutation: the alternation of a genetic sequence in anyway, which can cause a positive, neutral or negative effect.
Positive: evolution
Neutral: no harmful affect, which is most mutations
Negative: diseases
Mutations can be inherited, but also caused by environmental factors (mutagens), random meiotic errors, or errors within the cell (interpase g2)
What are the two types of mutations? What are they generally?
Point mutation: (Small mutations affecting one nucleotide) (Small mutations can have a big effect) single change
Chromosomal mutation: Large scale mutation, referring to the whole chromosome or large segments of nucleotide bases **ie: nondisjunction (whole chromosome) or large scale deletion (segments of the chromosome)
What is a point mutation? What are the 3 ways it can happen? (Explain the 3 ways, and their effect)
By having a point mutation what happens?
-> 3 types of mutations that can happen because of a point mutation?
Point mutation: 1 simple and single change to the nucleotide sequence by either deletion, insertion, subsitution
Deletion: one nucleotide base is deleted (which shifts everything backwards) (which can affect the many codons depedening on what nucleotide base was deleted)
Insertion: the addition of a nucleotide base, adding a letter. (Shifts everything forwards, which can affect many codons)
Substution, changing a nucleotide base (a single letter), which only affects 1 codon
All of this can lead to the potientally creating a different protein (because you are chaning the amino acid sequence)
Building a different protien = affect cell structure and function (change in sequence = change in protein) However this is all potiental, because not all of a nucleotide sequence is a coding region.
Most of the nucleotide sequence is a non-coding region. There point mutations crease 3 types of mutations:
Silent mutation = no effect on the amino acid sequence
Missense mutation = creation of a different protien
Nonsense mutation = a complete stop in a codon (completely unfunctional)
Inheriting mutation: Are all mutations inherited? When does it occur? What increases mutations to happen?
What are the two types of mutations (inheriteance) that can happen to a person (generally)? (Which mutation can be inherited)?
No not all mutation are inherited, as some can be caused randomly or is affected by environmental factors.
Can occur during meiosis/mitosis or during G2 in interphase when DNA is not replicated properly or not checked for/repaired properly before going into meiosis
As you grow older, you increase the risk of having mutations.
**GERM-LINE MUTATIONS and SOMATIC MUTATIONS **
germ-line mutations can be passed down because it affects your gamates
somatic mutations = only affects your body cells therefore cannot be inherited
-> usually only happens at a certain patch of area on your body
->no gamates are affected
What is the difference between inversion and translocation?
Inversion is the change in orientation of the nucleotide bases. No nucleotide base is loss or gained.
Translocation: only between non-homologous chromosomes, it is the act of breaking off a piece of DNA and reattaching. DNA is both loss and gained. (Creation of genetic diversity)
What are chromosomal mutations (general examples of chromosomal mutations?)
What are the 4 ways nucleotides can be affected in chromosomal mutations? (Explain)
Large scale changes to the nucleotide sequence, involving the whole chromosome or large sections of the chromosome.
ie: nondisjunction (**whole chromosomes **not splitting properly during anaphase)
Large scale deleteions (large segments of nucleotide squence being deleted)
NUCLEOTIDES being affected:
-> Inversion
->Deletion
-> Translocation
->Duplication
Inversion:
Chromosome sequence is written backwards/in a reversed order
-> There is no gain or loss in the base pairs/segments on orientation is changed
-> Can affect gene reputation/protien structure and function, however not guarenteed (as some amino acids despite in different orientations can code for the same protien)
Deletion:
Large sections of the chromosomes are deleted (Not just one nucleotide base, but many nucleotide bases)
Translocation:
The movement of large segments of nucleotide bases, which creates new genes.
ONLY BETWEEN NON-HOMOLOGUS CHROMOSOMES
-> Fragments of DNA breakoff and exchange/reattach to places on a different chromosomes, similar to crossing over however happened detween different chromosomes
->Genes may be altered mid sequence.
Duplication:
Segments of nucleotide bases are repeated (Double readings)
What are somatic mutations?
Mutations in body (somatic) cells are not passed onto offspring
only affects your body cells therefore cannot be inherited
-> usually only happens at a certain patch of area on your body
->no gamates are affected
What are germ-line mutations?
Germ-line mutations in sex cells (gametes) can be passed onto offspring
Dominant mutation - expressed in the first generation
Recessive mutation - expressed in later generations
What are two examples of Mutations? (Pros and cons, plus what are they (generally)?
-> Sickle cell amenia (con)
->Being lactose tolerate when you are older (pro)
What is sickle cell amenia, what type of mutation is it? What nucleotide base is effected? What are the pros and the cons?
Sickle cell amenia is when your blood cells are shaped like a C (caused by adeneine being subsituted for thymine) (point mutation)
->Results in blood clots, low oxygen levels, pain, and risk of infections (CONS)
Pro: (Only for carriers: people who do not have the disorder, but carry the gene for the disorder to be passed down)
Ability to naturally get ride of parasited like malaria, because if parasites enter body o2 levels go down, and therefore your blood starts to sickle.
the infected sickle cells are removed by your body, which removes the parasite.
What is lactose intolerance and tolerance? How is this considered a positive mutation?
Lactose intolerate = not enough production of the enzyme called lactase.
all babies are born lactose tolerate because they need milk to survive, however as we grow older we naturally lose the production of the enzyme lactase. (Severity ranges)
Therefore, if you are able to tolerate lactose as an adult, you are genetically mutated, and it is a postive mutation.
What causes a mutation? (two types of the cause of a mutation)
What are the differences between the two?
1) Spontaneous mutations (accidents that cannot be controlled)
-> Caused by meiosis/mitosis errors
->Errors in interphase refering to DNA not being copied correctly
2) Induced mutations (mutations that happen because of outside environments/exposure to outside factors)
->caused by mutagens such as (radation, plastics, and viruses)
->ability to control/leseen the risk of them
Both spontanenous and induced mutations can be inherited
What are transposons? How does it happen? What is it’s effect?
Transposons: Known as jumping genes
A gene/segment of nucleotide bases ability to insert inself into a different area or a different chromosome (Ability to move itself everywhere at any tme)
i.e: Corn: transposon inserted into gene for purple kernels, purple gene is disrupted, resulting in white kernels
In rare cases hemophilia is caused by a transposon - if a transposon inserts itself into a normal blood factor VIII gene, then the individual, if male, will be affected by hemophilia
What are the differences between transposons and translocation?
Refer to what moves, what causes it, the scale, and what happens/the result
Transposon is a specific gene, therefore a small squence of DNA, can happen either by cut or paste or copy and paste, and usually leads to a small disruption within the organism
White translocation is a LARGE scale chromosomal segment movement. It only happens between non-homologous chromosomes and involves millions of base pairs. Causes large-scale genetic disruptions.
What is antibiotic resistance? (Generally?)
What is resistant bacteria? (How?)
What is the importance of finishing your antibiotic?
How does cell division play a role in duplicating resistant bacteria?
Bacteria become resistant to antibiotics due to mutations
1) Resistant bacteria is a mutation.
2) If antibiotics are not finished properly, resistant bacteria is left and has the ability to reproduce assexually, and make the bacteria resistant.
