Mrs Zainab's Tourettes - Gene Expression Flashcards
(75 cards)
Do proteins form DNA?
Proteins do not form DNA directly but are essential in its synthesis and regulation.
Enzymes assist in DNA replication, and histones help package DNA.
What is a mutation?
A mutation is a permanent, heritable change in the DNA base sequence.
It can impact how genes function or are expressed.
What is a polymorphism?
A polymorphism is a common DNA variation in a population, often neutral or beneficial.
Example: Single Nucleotide Polymorphism (SNP).
What are the types of mutation?
Types of mutation include:
* Chromosomal Mutation
* Gene Mutation
What is a chromosomal mutation?
Involves large segments of chromosomes.
Examples include deletion, translocation, duplication, inversion, and substitution.
What is a gene mutation?
Involves small-scale changes, such as point mutations.
These mutations can alter how genes function.
List the types of chromosomal aberrations.
Types of chromosomal aberrations include:
* Deletion
* Translocation
* Duplication
* Inversion
* Substitution
What is aneuploidy?
Aneuploidy is the gain or loss of a chromosome.
Example: Trisomy 21 (Down syndrome).
What is polyploidy?
Polyploidy is the presence of extra genome sets, common in plants.
It is linked to giantism and cancer resistance.
What are the advantages of chromosomal mutations?
Advantages include:
* Provide survival advantages (e.g., lactase persistence)
* Contribute to human diversity (e.g., hair and eye color)
* Provide disease resistance (e.g., sickle-cell for malaria resistance)
What are the disadvantages of chromosomal mutations?
Disadvantages can include genetic disorders such as:
* Down syndrome (Trisomy 21)
* Edwards syndrome (Trisomy 18)
* Turner syndrome (X monosomy)
* Klinefelter syndrome (XXY)
What is the frequency of gene mutations?
Approximately 1 mutation occurs every 1 billion base pairs.
Each cell has about 6 mutations.
What are the types of gene mutations?
Types include:
* Hereditary (germline)
* Acquired (somatic)
* De novo
* Mosaicism
What are common causes of gene mutations?
Causes include:
* DNA replication errors
* Spontaneous changes (deamination, depurination)
* Mutagens (UV, chemicals, X-rays)
* Transposons (jumping genes)
What is epigenetics?
Epigenetics refers to changes in gene expression caused by environmental/lifestyle factors, not DNA sequence changes.
Example: Long lifespan in Okinawa linked to diet and exercise.
What are examples of mutagens?
Examples include:
* Chemical mutagens (e.g., mustard gas)
* Radiation (e.g., Hiroshima)
What diseases are caused by mutations?
Diseases include:
* Sickle-cell anemia (missense mutation)
* Hemophilia A/B
* Thalassemia
* MDR-1 gene mutation in cancer cells
What is a substitution mutation?
A substitution mutation is a change in one base that may have little effect.
Example: ‘The cat ate the rat’ → ‘The hat ate the rat’.
What is an insertion mutation?
An insertion mutation adds extra bases, potentially causing a frameshift.
Example: ‘The cat ate the rat’ → ‘The cca tat eth era t’.
What is a deletion mutation?
A deletion mutation removes bases, potentially causing a frameshift.
Example: ‘The cat ate the rat’ → ‘The ata tet her at’.
Which type of mutation has the least effect?
Substitution mutations often have the least effect.
They may be silent.
Which type of mutation has the most effect?
Insertion and deletion mutations typically have the most effect due to frameshifts.
Major change in protein structure.
What causes Tay-Sachs Disease?
Tay-Sachs Disease is caused by a frameshift mutation that prevents the breakdown of fatty substances in neurons.
It results in a fatal disorder.
