19: Genomics Flashcards
Module 4, Lesson 2
Early efforts in genomics focused on ____ and ____ genes.
Isolating and sequencing
The complete human genome was sequenced by….
2003
Genomics integrates ____ and ____ genetics to better understand genes.
Classical and molecular
List four methods of genomics.
- Mapping genomes
- Sequencing genomes
- Genome annotation
- Genome analysis
True or false:
Like regular maps, genome maps can be high or low resolution.
True
List the two main types of genome maps.
- Genetic maps
- Physical maps
____ are derived from recombination frequency and linkage analysis.
Genetic maps
Genetic maps provide the ____ location of genes.
Relative
____ feature nucleotide-level resolution.
Physical maps
Physical maps show the ____ location of genes.
Precise
List two types of “landmarks” that can be used as markers in the DNA sequence.
- Enzyme cutting sites
- Small segments of DNA
Physical maps show the ____ location of a marker.
Absolute
On ____ maps, the distance between markers is measured in base-pairs (bp) or kilobase-pair (Kb).
Physical
____ map the location of restriction enzyme cut sites.
Restriction maps
____ are used by researchers to study entire chromosomes or genes that can move between chromosomes.
Chromosome maps
____ maps use staining techniques to identify regions of interest.
Chromosome
A major advantage of chromosome maps is that they…
Enable researchers to view large pieces of DNA at a glance
____ maps combine high resolution with the ability to view large pieces of DNA at once.
Sequence-tagged site
(STS)
A small stretch of DNA found in only one location on the genome that is then amplified using PCR is called a…
Sequence-tagged site
Researchers use the presence or absence of STS to organize fragments into…
A continuous sequence
(contig)
The highest resolution physical map is a…
Base-pair sequence
What three things do all sequencing methods rely on?
- PCR
- Electrophoresis
- Chain-terminating nucleotides
Dideoxynucleotides (ddNTPs) are an example of…
Chain-terminating nucleotides
ddNTPs are different from normal nucleotides in that they…
Lack a 3’ OH group, which prevents additional bases from being added to the chain
____ allow DNA to be sequenced over a series of several reactions.
Manual sequencing reactions
True or false:
A ddNTP can have any of the four nucleotide bases (A,C,T,G).
True
Manual sequencing reactions were developed by…
Fred Sanger
Dideoxy sequencing is a(n) ____ form of DNA sequencing.
Automated
List the main steps of dideoxy sequencing.
(five)
- Begin with strand of unknown sequence
- Subject strand to PCR
- Incorporate ddNTPs
- Separate synthesized fragments via electrophoresis
- Use laser and photodetector to identify bases
During automated DNA sequencing, ddNTPs are labeled…
With a different flourescent marker depending on whether they are A, C, T, or G
True or false:
When DNA polymerase synthesizes DNA, it randomly incorporates one of the ddNTPs.
True
The smallest DNA fragments produced in PCR correspond to the ____ end of the molecule.
5’
____ is a form of sequencing that is faster, cheaper, and capable of sequencing large DNA fragments at once.
Next-generation sequencing
List the main steps of next-gen sequencing.
(four)
- Large strand of DNA is fragmented
- Single-stranded DNA fragments are attached to a solid surface
- Multiple copies are created using PCR
- DNA polymerase incorporates nucleotides
Why does next-gen sequencing create multiple copies of the DNA fragment?
It ensures accuracy in sequencing
Next-gen sequencing uses a ____ to begin DNA synthesis,
Universal primer
Next-gen sequencing uses special nucleotides to…
Terminate DNA synthesis
True or false:
Unlike automated sequencing, next-gen sequencing does not use flourescent markers.
False
Both use flourescent markers and lasers to identify bases.
The chain-terminating nucleotides used in next-gen sequencing are…
Reversible
(can be changed back into normal nucleotides)
Why is it important that the chain-terminating nucleotides are reversible?
It allows each DNA fragment to be sequenced multiple times, with new chain-terminating nucleotides being added each time
After sequencing, gene fragments must be…
Assembled into complete sequences
True or false:
Most genomes can be sequenced in a single step.
False
Most are too large for this to happen.
Gene fragments are assembled into a contig by…
Matching overlapping sequences
In the ____ method, a genome is broken down into large pieces of DNA called clones.
Clone-contig
List the steps of the clone-contig method.
(three)
- Genome is broken down into clones
- Clones are arranged using STS landmarks
- Clones are broken down into smaller fragments for sequencing
In the clone-contig method, after the small fragments are sequenced, they are used to make…
Clone sequences
Clone sequences are combined to make a…
Larger contigous segment
(contig)
The ____ method does not rely on any genetic or physical maps.
Shotgun
In the shotgun method, the entire genome is…
Broken into more manageable fragments for sequencing
The shotgun method uses computers to…
Reassemble fragments using overlap between nucleotide regions
True or false:
Both the clone-contig method and the shotgun method are often used to sequence a single genome.
True
The human genome project used ____, ____, and ____ as sequencing methods.
Genetic maps, clone-contig, and shotgun
The human genome project found that the human genome contains around ____ genes.
20,000
True or false:
Organismal complexity is not merely a function of genome size or gene number.
True
____ is used to assign information about DNA sequences.
Genome annotation
DNA sequences and their annotations can often be found in…
Online databases
A potential gene sequence, such as a start codon + amino acids + stop codon is called a(n)…
Open reading frame
(ORF)
Databases of gene sequences can be updated as…
New information about gene functions are discovered
DNA sequences that produce protein or are transcribed into functional RNAs are called…
Coding sequences
Up to ____% of the DNA in the human genome may be non-coding.
99
DNA sequences that do not code for proteins or functional molecules are called…
Non-coding DNA
List the seven categories of non-coding DNA.
- Introns
- Segmental duplications
- Pseudogenes
- Structural DNA
- Simple sequence repeats
- Transposable elements
- Noncoding RNA
____ are noncoding DNA segments that make up the majority of a human gene.
Introns
____ are regions of the genome that have been duplicated.
Segmental duplications
____ are sequences with characteristics of genes but that are not functional genes.
Pseudogenes
Pseudogenes are also sometimes called…
Inactive genes
____ is constitutive heterochromatin located near the centromeres and telomeres.
Structural DNA
____ are stuttering repeats of a few nucleotides, repeated thousands of times.
Simple sequence repeats
____ are a diverse group of DNA sequences that can move from one chromosome to another.
Transposable elements
Transposable elements are also sometimes called…
“Jumping genes”
True or false:
Transposable elements often copy themselves as they move.
True
List the four categories of transposable elements.
- Long interspersed elements
- Short interspersed elements
- Retrotransposons
- DNA transposon fossils
Long interspersed elements (LINEs) are…
Active transposons
Short interspersed elements (SINEs) are…
Active transposons
Each end of a retrotransposon contains…
Long terminal repeats (LTRs)
____ are RNAs that do not code for protein but have regulatory functions.
Noncoding RNA
True or false:
Many functions of noncoding RNA are currently unknown.
True
The ____ was created to identify all functional elements in the human genome.
ENCODE project
(Encyclopedia of DNA Elements)
The ENCODE project claimed that ____% of human DNA is functional.
80%
ENCODE researchers defined “functional” as…
Any sequence with reproducible biological activity
List three reasons why some disagree with ENCODE’s findings.
- “Biological activity” alone is not enough to call DNA functional
- Sites of enzymatic activity are not necessarily functional
- Evolutionary biology focuses on DNA that has been selected for over time
____ focuses on identifying the roles and purpose of DNA elements.
Genome analysis
List the three primary approaches to genome analysis.
- Comparative genomics
- Functional genomics
- Proteomics
____ reveals conserved regions of DNA.
Comparative genomics
Comparative genomics uses information from one genome to…
Learn about a second, related genome
Comparative genomics is based on…
Synteny
____ is the conserved arrangement of DNA in related genomes.
Synteny
Conserved regions of DNA are also called…
Syntenous regions
List three applications of comparative genomics.
- Predict gene function
- Locate similar genes
- Predict evolutionary relationships
____ can be derived from comparing physical maps.
Synteny
____ uses biotechnology to highlight connections between the genotype and phenotype.
Functional genomics
List the three main categories of functional genomics.
- Study of all the RNA molecules produced by the genome
- Study of all proteins produced by genome
- Study of interactions between proteins
All the RNA molecules produced by the genome are called the…
Transcriptome
All the proteins produced by the genome are called the…
Proteome
The study of the proteome and the interactions between proteins is called…
Proteomics
List two methods of studying the transcriptome.
- DNA microarrays
- RNA sequencing (RNA-seq)
Researchers use ____ to determine which genes are expressed at a particular location or time.
DNA microarrays
The dots on a microarray chip represent…
Genes
The different colors of dots on a microarray chip represent…
The level of gene expression
Knowing if a gene is expressed can provide insight into…
(two)
- The function of the gene
- Its interactions with other genes
____ uses next-generation technology to capture all the mRNA transcripts created at a particular time.
RNA-seq
RNA-seq allows researchers to…
Collect information on all gene expression, not just the genes of interest
True or false:
All mRNA that are successfully transcribed will be translated into proteins.
False
Just because an mRNA is transcribed does not mean the protein product will be translated.
____ is the study of the collection of proteins encoded in the genome.
Proteomics
List two reasons why it is difficult to predict a protein’s structure from DNA sequences alone.
- Alternative splicing
- Post-transcriptional modification
List two techniques used in proteomics.
- Mass spectrometry (mass spec)
- Protein microarrays
Mass spectrometry is used to calculate…
The charge-to-mass ratio of each peptide in a protein
How does mass spectrometry identify proteins or amino acids?
It compares the charge-to-mass data to a database
Protein microarrays contain ____ that are used to identify a protein.
Antibodies
____ uses computer programming, math and modeling to analyze data.
Bioinformatics
Applying bioinformatics techniques to proteomics enables…
Rapid identification of proteins
Bioinformatics can predict protein structure using…
(two)
- Chemical properties of amino acids
- Principles of how amino acids interact
List two applications of genomics.
- Synthetic biology
- Diagnostics
____ involves creating biological organisms to solve problems.
Synthetic biology
In medicine, diagnostics can be used to…
Identify harmful genes
In forensics, diagnostics can be used to…
ID remains and weaponized pathogens
List two areas of genomics that have created ethical concerns.
- Research of infectious diseases
- Gene patenting