What is a genome?

Report
• A genome is the full set of genetic information
that an organism carries in its DNA.
• The study of any genome starts with the
analysis of chromosomes.
• Chromosomes are bundles of DNA and protein
found in the nuclei of eukaryotic cells.
Fruit fly
chromosomes
How are chromosomes analyzed?
• To study chromosomes, scientists photograph chromosomes
in mitosis and arrange them in a picture known as a
karyotype.
• A karyotype shows the complete diploid set of chromosomes
grouped together in pairs, arranged in order of decreasing
size.
• A typical human karyotype contains 46 chromosomes
arranged in
23 pairs.
1. Define What is a karyotype?
Let’s Analyze!
Down’s Syndrome
• Called TRISOMY 21
• genetic disorder that
occurs in approximately 1
of 800 live births
• SYMPTOMS
•
•
•
•
•
Cognitive impairment
Learning disabilities
Develpmental delays
Low muscle tone (infancy)
Characteristic facial
features
• Heart defects
• Other health issues
• CAUSES
Non-disjunction of the 21st
chromosome
Klinefelter’s
Syndrome
• Klinefelter’s syndrome occurs
in about 1 out of 1,000 males.
• XXY (extra copy of an X
chromosome)
• SYMPTOMS
•
•
•
•
•
Not always noticiable
symptoms
Large hips
Small breasts
Fat around the abdomen
Small testicles
• CAUSES
•
Non-disjunction of the sex
chromosomes in either
sperm or egg
How is DNA fingerprinting used to
study genomes?
• No two individuals, except identical
twins, are genetically identical.
• DNA fingerprinting analyzes sections of
DNA that may have little or no function
but that vary widely from one individual
to another.
.
(contd.)
HOW IS DNA
Fingerprinted?
1. DNA is cut by
restriction
enzymes
2. scientists use gel
electrophoresis
to separate and
analyze the
differently sized
fragments.
3. Scientists
compare the
BANDS made
2. Describe How do scientists separate DNA?
DNA fingerprinting is used to study
genomes?
Teachers…Click on the following link
http://www.rocklin.k12.ca.us/staff/avrudny/Scie
nce/Advanced_Biology/Unit_8/DNA_Fingerprint
ing_Activity.pdf
Focus on the bottom of the activity only! Crime
Scene Analysis CASE 1 and CASE 2
• The Human Genome Project was an international
effort to sequence all 3 billion base pairs of human
DNA.
• Other important goals included sequencing the
genomes of model organisms to compare to human
DNA, developing technology to support the
research, exploring gene functions, studying human
variation, and training future scientists.
• Today, multiple copies of the human genome, along
with those of hundreds of other organisms, are
available to the public.
3. Explain What are some of the goals of the Human Genome Project?
Human beings have always tried to improve
the plants and animals they use for food,
work, and companionship.
Selective breeding describes the process by
which humans allow only those animals with
certain characteristics to produce the next
generation.
Two Methods of Selective Breeding
1.Hybridization
2.Inbreeding
Crossing dissimilar
individuals together to
bring together the best of
both organisms
Continued breeding of
individuals with similar
characteristics
What are transgenic organisms?
• It is possible to construct organisms that are
transgenic, containing genes from other species.
• Genetic engineers can now produce transgenic
plants, animals, and microorganisms. By examining
the traits of a genetically modified organism, it is
possible to learn about the function of the
transferred gene.
• This ability has contributed greatly to our
understanding of gene regulation and expression.
What is recombinant DNA?
Recombinant DNA consists
of DNA molecules that have
been taken from two sources
and then recombined.
Recombinant-DNA technology
makes it possible to construct
DNA molecules with nearly any
combination of genes.
Cloning
• Clone – member of
a population of
genetically
identical cells
First dog successfully cloned
Infer Using the example of the sheep cloning, why
wouldn’t the cloned lamb resemble its foster
mother?

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