6.1 Studying the Human Genome Flashcards
What is the difference between a gene and
a genome?
gene: units of inherited information that code for a specific trait or function
genome: full DNA sequence of
an organism
What were the primary goals of the Human
Genome Project?
two main goals:
first, to determine the nucleotide sequence of all the DNA in human chromosomes
second, to identify the location and sequence of every human gene
How are restriction enzymes used to
manipulate DNA?
Restriction enzymes are bacterial proteins that cut DNA wherever a particular nucleotide sequence
occurs
What are restriction fragments?
The pieces of DNA made by cutting it
with restriction enzymes are called restriction fragments
What does DNA sequencing determine?
the order of nucleotides in DNA
What fraction of the human genome contains
genes?
1.5-2%
What does the remaining 98% of the human genome contain?
repeated nucleotide sequences, regions
that regulate genes, and even DNA
sequences inserted from viruses.
Which areas of science does bioinformatics
bring together?
biology & information science
What term is used for the study of genomes?
genomics
How are DNA chips used for genetic testing?
DNA chips: small glass wafer or slide spotted with an
array of single-stranded DNA fragments.
-Some spots, for example, could contain DNA with mutations known to cause cystic fibrosis.
-used to determine whether the DNA from a particular individual contains a mutation in genes
Which species has more genes in its
genome: the mustard plant or the nematode
mustard plant
Which species has more DNA in its genome:
the rice plant or the fruit fly?
rice plant
Describe two ways in which model organisms
are used to understand the function of human
genes.
-enable scientists to follow the inheritance of genes
through many generations in a relatively short time
-Cross-species comparisons can help us understand the functions of particular genes.
For example, if a nucleotide sequence in the human
genome is similar to a particular mouse gene with a known function, this gives us insight into the function of the human sequence
Describe three benefits of having a complete
map of the human genome
-Mapping genes enables researchers to identify genes associated with diseases.
An example is Parkinson’s disease. This progressive
disease gradually destroys brain cell function, causing tremors, speech difficulties, and rigid muscles
-understand inherited disorders and their treatment.
-earlier detection of genetic predispositions to disease
What are three reasons that mice are used
as model organisms in genetic studies?
-Mouse development and genetics have been well studied
-Mice and humans have a similar number of nucleotides in their genomes and a comparable number of genes
-In most cases, for a particular human gene
a mouse counterpart can be found
Suggest one or more drawbacks to using
mice in genetic studies
-fail to accurately mimic human disease phenotypes
-poor models to study inflammation in humans, a condition present in many humans
-research mice are inbred and do not capture the genetic variation existing in human population
How are DNA sequencing and gene mapping
related?
A sequence spells out the order of every DNA base (nucleotides) in the genome, while a map simply identifies a series of landmarks in the genome (enables researchers to identify genes associated with diseases)
Should anyone have the right to own DNA
sequence data? Justify your response.
- yes, because if we privatize it, these companies will raise the price unbelievably high and make it inaccessible to people that really need it
e.g. single mom has a disease and the cure used to cost $15 and now it costs $850 per bottle. She can’t afford it now and will die
Pros & Cons of DNA chips
pros:
-gene chips could become a useful tool in personalized health care.
-knowledge about genomes can have useful applications in agriculture as well as medicine
-for example, sequencing the rice genome has led
to ways of making it a more nutritious food source.
cons:
-microarrays do not have the ability to show changes at the protein level. These changes are an important factor of toxic effects on the body.
-little research available
-results influenced by minor changes
-complex data, difficult to interpret
What is the Human Genome Project?
-determined the nucleotide sequence of all the DNA in human chromosomes, and identified the location and sequence of every human gene.
-other goals included exploring gene functions, studying variations among different people’s DNA, and comparing human DNA with DNA from other species.
What can you learn by comparing restriction fragment gels?
-can be used to identify the source of a disease outbreak
For example, if bacteria that are making people ill produce the same restriction fragments as bacteria in a food sample, the food can be identified as the source of the illness.
