Week 4 DNA Sequencing And Human Genime Project Flashcards
What does DNA polymerase do?
Synthesizes DNA by joining nucleotides using a template strand.
What is Sanger sequencing?
A method using ddNTPs to terminate DNA synthesis, producing fragments that can be separated by size to determine the sequence.
What are ddNTPs and what is their role in Sanger sequencing?
Dideoxynucleotides that terminate DNA synthesis when incorporated, creating fragments of varying lengths.
What is capillary electrophoresis?
A method to separate DNA fragments by size using an electric field in a capillary tube; used in modern Sanger sequencing.
What is next-generation sequencing (NGS)?
A high-throughput method that sequences millions of DNA fragments in parallel, e.g., Illumina sequencing.
What is sequencing by synthesis?
A method where DNA polymerase incorporates fluorescently-labeled nucleotides and a detector reads the signal to determine the sequence.
What is nanopore sequencing?
Sequencing DNA by threading it through a nanopore and reading the electric current changes caused by each base.
What was the significance of the MinION device?
It allowed real-time, portable DNA sequencing—first used in space by NASA astronaut Kate Rubins.
What was the Human Genome Project?
An international effort to map and sequence the entire human genome.
When was the first draft of the human genome completed?
2001
What is clone-by-clone sequencing?
A method where large DNA fragments are cloned into BACs and sequenced individually to assemble the genome.
What are BACs?
Bacterial Artificial Chromosomes used to clone large DNA fragments for sequencing.
What is whole-genome shotgun sequencing?
Sequencing many random DNA fragments and assembling them computationally without using mapped clones.
Which company pioneered whole-genome shotgun sequencing?
Celera Genomics.
What are genetic and physical mapping?
Genetic mapping uses recombination data; physical mapping measures actual distances in base pairs.
What is genome assembly?
The process of aligning and merging fragments of DNA to reconstruct the original genome sequence.
Why was the Human Genome Project significant?
It transformed genetics, enabling personalized medicine, disease gene discovery, and biotech advancements.
What challenge did Sanger sequencing face for large genomes?
It could only sequence short fragments (300–10,000 bp), making whole-genome sequencing time-consuming and costly.
