Lec4 | Mutations and Genetic Variation Flashcards
Mutations are changes in DNA that can result in…
permanent alteration to the sequence of nucleotides.
Somatic mutations occur in…
non-reproductive cells.
Somatic mutations affect…
only a patch of tissue.
Somatic mutations are inherited by…
None of the gametes carry this mutation
Germline mutations occur in…
cells that give rise to gametes.
Germline mutations affect…
the entire organism.
Germline mutations are inherited by…
half of the gametes that carry this mutation.
Inherited mutations are passed down from…
parents to offspring.
Inherited mutations can be present in…
germline cells.
Spontaneous mutations are caused by errors in…
cellular mechanisms.
What are some mechanisms that spontaneous mutation can regulate?
chromosome segregation, recombination, DNA replication, DNA repair.
Spontaneous chemical damage to DNA can cause…
De-novo mutations.
Induced mutations are caused by exposure to…
environmental factors/mutagens.
Examples of radiation that cause mutations are…
UV (sunlight), X-rays.
Examples of chemicals that cause mutations are…
carcinogens (cigarettes), processed food additives.
Examples of infectious agents that cause mutations are…
some viruses (e.g., HPV), and bacteria (e.g., Helicobacter).
Chromosomal mutations change…
chromosome structure.
In chromosomal mutations, the total amount of genetic information can…
change or remain the same but be rearranged.
Deletion, duplication, and insertion are types of chromosomal mutations in which…
the total amount of genetic material changes.
Inversion and translocation are types of chromosomal mutations in which…
the genetic material is rearranged
Point mutations change…
a single nucleotide.
Three types of point mutations are…
silent, missense, nonsense.
Deletions involve the loss of…
one or more nucleotides from a segment of DNA.
Microdeletions are…
small deletions, ranging from a single nucleotide to multiple nucleotides.
Macrodeletions are…
deletions of large parts of the chromosome.
Insertions involve the addition of…
one or more nucleotides into a segment of DNA.
Microinsertions are…
small insertions of genetic material.
Macroinsertions are…
large insertions of genetic material.
Indels are…
frameshift mutations that affect the reading frame of a gene.
Frameshift mutations result in…
large numbers of altered amino acids.
Inversions occur when…
a chromosomal segment breaks off and reattaches in reverse orientation.
In an inversion, DNA may…
or may not be lost in the process.
Paracentric inversion is when…
there is an inversion in a chromosome within the long (q) arm.
Translocations occur when…
a chromosome breaks and the fragmented pieces re-attach to different chromosomes.
How many chromosomes are involved in a translocation?
typically two.
Point mutations occur when…
a single base pair is added, deleted, or changed.
Most point mutations are…
benign.
Point mutations can change…
gene expression or alter encoded proteins.
Three types of point mutations are…
silent, missense, and nonsense.
A silent mutation does not affect…
the sequence of amino acids in the gene’s protein.
Missense mutations alter the genetic code to produce…
a different amino acid than the usual one at that position.
Nonsense mutations cause…
a premature stop codon.
The presence of a premature stop codon results in…
a shortened protein that is likely non-functional.
Harmful mutations can cause…
loss of function or gain of function.
Beneficial mutations can provide…
protection.
Neutral mutations can contribute to…
genetic diversity.
Sickle cell anemia is a mutation that provides an advantage that allows individuals to…
have a greater chance of surviving Malaria.
The great majority of mutations are…
neutral (no effect on phenotype).
There has been an increasing trend to use the term… instead of mutation
DNA variant
DNA variants associated with an altered phenotype (causing disease) are described as…
mutations.
Think of mutation as a process that creates genetic variation IF…
a disease phenotype is NOT a result.
SNPs are the most common type of…
genetic variation among people.
SNPs involve a change in…
a single nucleotide base.
SNPs occur approximately every…
300 nucleotides.
SNPs account for about… of all human genetic variation
90%
Most SNPs are found in… but those in coding regions can…
non-coding regions, affect gene function.
SNPs can be linked to susceptibility to diseases such as…
diabetes, cancer, cardiovascular disorders.
SNPs can affect individual responses to drugs by…
altering drug metabolism enzymes, transporters, or targets.
CNVs are segments of DNA that vary in…
copy number between individuals.
CNVs involve duplications or deletions of genomic regions ranging from…
1,000 base pairs to several million base pairs.
CNVs occur due to errors in…
DNA replication, recombination, or repair mechanisms.
Structural variations can lead to… (duplications) or… (deletions) of genes
extra copies, missing copies
Gene Dosage Effect (CNVs) are changes in the number of gene copies that can…
increase or decrease gene expression.
Phenotypic Variation (CNVs) can contribute to…
differences in traits and disease susceptibility.
CNVs have been linked to conditions such as…
cancer, neurodevelopmental disorders, and immune system diseases.
Amplification of the HER2 gene can lead to…
overexpression of the HER2 protein (influences treatment in breast cancer).
CNVs affect drug metabolism by…
altering the copy number of genes encoding drug-metabolizing enzymes.
CNVs influence individual responses to medications, which is important for…
personalized medicine.
Pharmacogenomics is the study of…
how genes affect a person’s response to drugs.
Pharmacogenomics involves tailoring drug therapy based on… and predicting…
genetic makeup, adverse drug reactions.
Personalized medicine involves creating treatment plans based on…
individual genetic profiles.
Personalized medicine leads to…
increased drug efficacy and reduced side effects.
Drug development involves designing drugs that…
specifically target mutated proteins in diseases.
Biotechnology applications include… and…
gene therapy to correct genetic defects, use of recombinant DNA technology to produce therapeutic proteins.
Biotechnological tools are used to…
identify and characterize genetic mutations.
Pharmaceutical science focuses on…
designing efficient potential therapeutics.
