Neurogenetics Flashcards
The building blocks of genetic code are called…
Nucleotides (or bases)
How many different types of nucleotides/bases are there in DNA?
4
What are the bases in DNA called? ACGT
- Adenine
- Cytosine
- Guanine
- Thymine
What are the building blocks of proteins?
Amino acids
What comprises the genetic code for a particular amino acid?
A specific sequence of 3 bases/nucleotides
How many bases are there in the human genome? (think: solar system)
3 Billion
How many genes code for proteins
20-25 thousand
The four bases/nucleotides appear in strict pairs. What is the pairing they appear in?
Cytosine with Guanine (C-G)
Adenine with Thymine (A-T)
What is the word for the full gamete of human chromosomes
The karyotype
How many chromosomes in the human karyoptype
46, in 23 pairs
What are the two types of chromosome
sex and autosomal
How is the function of a protein determined?
By its structure
How is the structure of a protein determined?
By its sequence of amino acids
Amino acids are made accordion got the instructions enshrined as sequences of three bases in the genome. What is the name we give to that sequence of three bases?
A codon
Does changing a single base necessarily change the associated amino acid?
No. It can, but not always
What is the name of the position on the genome at which the base/nucleotide differs between individuals (ie some of us ave a T and others have a G)
A Single-Nucleotide Polymorphism (SNP)
What is the name given to the two alternative basis of a SNP? (As in, could have a T or a G or etc )
Alleles
How is a genotype determined at a given SNP?
By the two alleles on the two copies of the chromosome
there are slight exceptions for the sex chromosomes on males
What is the term given to the presence, absence or value of a trait or traits?
Phenotype
There are a range of genetic variants.
What is the insertion-deletion variant and how can you tell if that’s what you’re looking at?
The reference string of nucleotides has got a chunk missing/added relative to the comparison string
If the strings are the same length, probably not dealing with insertion-deletion
There are a range of genetic variants.
What is the block-substitution variant and how can you tell if that’s what you’re looking at?
There’s a chunk of letters out of whack (and it’s not a inversion variant or a copy number variant)
With this one, just need to make sure it’s not actually an inversion variant
There are a range of genetic variants.
What is the INVERSION variant and how can you tell if that’s what you’re looking at?
This is the tricky one…
It’s basically A) the mirror version (like, the opposite types - the C to the G etc) and then (B) put in the reverse order… Oh lordy
There are a range of genetic variants.
What is the COPY NUMBER variant and how can you tell if that’s what you’re looking at?
This is where there is a sequence that is accidentally copied a bunch of times. Like in the reference or the alternative string, the letters CCG CCG CCG appear a bunch of times with no corresponding letters in the other string
Is mutation rare or common?
Rare