Mutations Flashcards
(47 cards)
Haemoglobin of sickle cell is ——
HbS ( occur beacuse glutamate is replaced by valine)
Mutations in ——— is the most effected among the stages of central dogma
DNA
They say mutations are errors in DNA coding
Causes of mutations
Inherited or spontaneous from environmental factors or errors in central dogma
The effects of mutations are usually found at——— level
Protein
DNA——> mRNA——> proteins
Mutations anywhere will result in error in proteins synthesis
What is a mutagens?
That can cause genetic mutations from physical or chemical substances and events
Mutagens can be —— or ——
Endogenous- that is already inside the body
Exogenous- that comes from environmental surroundings
The action of ROS can be prevented by ———
Antioxidants
When the ROS levels in ur body is too high, the doctors prescribe antioxidants to help prevent the ROS damage the DNA
Etidium bromide can be ——— mutagen
Etidium bromine- intercalator
Exogenous mutagen
The fluorescent used in electrophoresis for vision under UV light.
But they can disrupt the form of double stranded DNA can cause mutations
The action of base analogue
Pretend to be one base ( lets say Adenine)but function differently from what a normal base would function
Carcinogens are also mutagens
True
Are all mutations bad?
No. Natural evolution ——> mutations are crucial
Nonsense mutation
The translation ends early then supposed to because of the point mutation experienced in the mRNA strand
Eg, GCT——>CGA
But instead there is a mutation and ACT——> UGA (Stop codon)
Frameshift mutation
One nucleotide base added to the strand, and all the protein codings produce different amino acids
New alleles can be produced by——
Mutations
What is the chromosome number of zygote between the fusion of normal egg cell n and aneuploid Sperm n+1
2n+1
In severe cases, the klinefeltor syndrome may be ——- or ———
XXY or XXXY
X inactivation can also apply to kinefeltor syndrome men just like in normal female
Down syndrome karyotype, is it aneuploid or polyyploid?
Aneuploid, chromosome no= 47 not 3*23
What is reciprocal and non-reciprocal translocation?
Reciprocal; two chromosomes swapping segments.
Non-reciprocal- a chunk of chromosome moves to another
Bacteria reproduces asexually. How does their variation to disease causing pathogens and resistant to antibiotics arise?
By three methods
1. Transformation- a bacteria takes up DNA from environment, such as plasmid. If the foreign DNA is pathogenic——> the recipient bacteria becomes pathogenic as well and pass it to their descendants
- Transduction- by bacteriophage carrying a pathogenic DNA of a bacteria to another cell, some bacteriophages chop the DNA and make the transfer more likely
3 conjugation - one bacteria transfer DNA to another bacterium to which it is physically connected
How do mutations in viruses arise?
- Two types of viruses infect a host cell at the same time——> recombinant virus and gives rise to a new type of virus
- Viral mutation - very high in RNA viruses —> RNA pol doesnt proofreads and many errors lead to mutation s
Mutation
Permanent change in DNA sequence of a gene or chromosome
Gene mutation
Variation of one or few nitrogenous bases
Chromosomal mutation
Variation of entire stretches of DNA or change in chromosome number
