Genomics. Flashcards
Define an allele?
A different version of a gene.
E.g. the gene that codes for hair colour is made up of different alleles that code for different hair colours.
Define the banding pattern on a chromosome?
How the individual genes are arranged on a chromosome.
Define cytogenetics?
The study of different karyotypes from different organisms.
Define DNA sequencing?
The process of determining the exact order of nucleotides within a DNA molecule.
Define the exome?
The part of the genome that is composed of exons.
Define a gene?
A discrete hereditary unit that codes for a trait or a specific protein.
Define the genome?
All the genes that an organism possesses.
Define genomics?
The study of all of the genes within an organism.
Define a genotype?
The genotype consists of the specific genes that an organism possesses e.g. genes for and eye colour.
Define a haplotype?
A combination of alleles that are located next to each other on a chromosome.
Are haplotypes usually inherited together?
Yes.
Define a karyotype?
The arrangement of all of an organisms chromosomes into an order of size.
Define a microdeletion?
A deletion of between a few hundred and a few million base pairs on a chromosome.
These deletions are too small to be picked up via light microscopy.
Define Northern blot?
A molecular technique that evaluates different RNA’s.
What does the suffix omics represent?
It is used to indicate a genome wide approach or study.
E.g. genomics is the study of all the genes in the genome.
Define a phenotype?
The physical expression of an organisms genotype e.g. genes that code for blue eyes or blond hair.
Define a single nucleotide polymorphism?
Polymorphisms where the variance between alleles is caused by the difference of a single nucleotide within a genetic sequence.
Define Southern blot?
A molecular technique that evaluates different forms of DNA.
Define Western blot?
A molecular technique that evaluates different proteins.
What does the study of genomics look at?
All of the genes that are found within a particular organism.
Does the number of genes within an organism vary over time?
No.
What can lead to an increase or decrease of genes in an organism?
Mutations such as insertions and deletions.
Is genomics context dependent?
No, as the amount of genes in an organism does not change over time.
Is transcriptomics context dependent?
Yes, as the amount of mRNA in a cell will change over time.
What contributes to the overall phenotype of an organism?
The genome, the transcriptome, the proteome and the metabolome.
What will an mRNA dictate?
The protein that is produced.
What is the proteome directed by?
The transcriptome.
What is the transcriptome directed by?
The genome.
Is the production of mRNA context dependent?
Yes, as humans will produce different mRNAs at different stages throughout their life.
Will the environment influence the phenotype?
Yes, as the transcriptome and the proteome are dictated by the environment.
What are the 3 disciplines that are involved in the study of genomics?
Molecular biology.
Bioinformatics.
Computing.
Why are robots and computers often used in genomics?
To save time.
What are 6 things that an organisms genome can tell us about its life?
Developmental pattern.
Disease resistance or susceptibility.
Metabolism.
How the organism will react to specific drugs or toxins.
The history of the organism.
The environment that the organism lives in.
What are the 2 types of genomes that exist in nature?
Eukaryotic and prokaryotic genomes.
What kind of genomes tend to be more complex?
Eukaryotic genomes.
What material do most genomes tend to be made up of?
Deoxyribonucleic acid.
The exception to this is a few viruses that have RNA genomes.
What is the specific region of the cytoplasm of prokaryotic cells is the genome found in?
The nucleoid region.
Do prokaryotes contain extrachromosomal DNA?
Yes, in the form of plasmids.
What are plasmids?
Circular regions of DNA that can be acquired from the environment.
Is plasmid DNA part of the prokaryotic genome?
Yes.
Why is the eukaryotic genome more complex than the prokaryotic genome?
As it contains many more genes.
What are the 2 genomes that make up the eukaryotic genome?
The nuclear genome.
The mitochondrial genome.
Where is the nuclear genome found in eukaryotic cells?
In the nucleus.
What genes make up the mitochondrial genome?
All of the genes located within the mitochondria of eukaryotic cells.
What are mitochondria in plant cells known as?
Chloroplasts.
What is cytogenetics?
A branch of genomics where scientists look at the different karyotypes of different organisms.
What does the study of karyotypes allow scientists to do?
To identify different chromosomal abnormalities e.g. Downs syndrome.
What does euploidy refer to?
To the normal complement of 46 chromosomes that are found in humans.
What is aneuploidy?
When the number of chromosomes found in an organism differs from what is normally found.
What happens to most organisms that suffer from aneuploidy, before they are born?
They will be aborted before they are born as most forms of aneuploidy are not compatible with life.
What are 4 common types of aneuploidy that appear in humans?
Downs syndrome.
Edwards syndrome.
Patau syndrome.
Klinefelters syndrome.
What is downs syndrome charactersied by?
An extra chromosome 21 resulting in 47 chromosomes.
How will a males genome read if he is infected with Downs syndrome?
XY-47+21.
What is Edwards syndrome charactersied by?
An extra chromosome 18 resulting in 47 chromosomes in total.
How will a males genome read if he is infected with Edwards syndrome?
XY-47+18.
What is Patau syndrome charactersied by?
An extra chromosome 13 resulting in 47 chromosomes in total.
How will a females genome read if she is infected with Patau syndrome?
XX-47+13.
What is Klinefelters syndrome charactersied by?
When an organism contains an extra X or Y chromosome resulting in a genome of XXY or XYY.
What is Turner syndrom charactersied by?
When an organism only receives a single X chromosome.
What are strucutural chromosmal abnormalities caused by?
By damage to the chromosome or when a segment of the chromsome falls off from the original chromosome.
What results from strucutural chromosmal abnormalities?
A deletion of part of the genome.
What kind of scientists will create cytogenetic maps?
Cytogeneticist.
What will cytogenentic mapes be used to highlight?
How densely DNA is packaged into various areas of the chromosome.
What are bands on a cytogenetic map?
The areas where DNA is tightly packed into a chromosome.
How do cytogeneticists get bands to show up on a chromosome?
By staining the chromosomes with with a particular dye known as Geisma.
Will each chromosome within an organism display the same banding pattern?
No.
Each chromosome will display a different banding pattern.
What can the positioning of a band on a chromosome tell us?
Where a particular gene is located on a chromosome.
What does FISH allow scientists to do?
To view large DNA fragments on metaphase chromosomes or on interphase chromatin strands.
What is probe DNA labelled before it undergoes FISH?
Radioactive probes.
What will the lablled DNA be hybridised to when FISH is being performed?
Metaphase chromosomes.
What happens to chromosomes after they have undergone FISH?
They can be compared.
What are 3 common methods of comparing chromosomes after FISH has occurred?
Standard karyotype analysis.
Aneuploid screen test.
Detecting micro-deletions via FISH.