genetics-notes 15

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Transcript genetics-notes 15

Today we begin genetics
and super groovy
Note fun!!!!
Today more interesting
Genetics note fun !!!!!!!
“We Have Found the Secret to
Life”- Francis Crick, Feb 28th 1953
Watson and Crick
Why is Genetics Cool?
• Genetic Engineering- genetically modified
organisms- create desired traits in
organisms, such as disease and insect
resistant plants.
• Every living thing on Earth shares the same
life code
• Gene therapy and the medical field, ex.
Curing genetic disease such as cystic
• The social and ethical implications of
knowing the code of every living thing
The genetic material in all
Living things is located in
The nucleus of the cell.
Genetics –
Genes – located on
Chromosomes, Genes are sequences of
Which determines traits or
Hereditary information.
Genes are found on the
chromosomes of cells in the
Chromosomes – found in pairs
in the nucleus, specific
Spots on the chromosomes
That control various traits
Are genes.
Genes are
Made of
Genes occur in pairs and one
Or more pairs of genes may
Control a trait. ( ex= eye
Color. There are many genes
In a chromosome.
Humans have
25,000 genes
These are ?????????
Human gene codes
Heredity – passing of genetic
Information by reproduction.
Types of reproduction
Asexual – one parent,
Produces identical offspring.
= clones (mitosis)
Sexual – two parents - half
Genetic info from sperm &
Half from egg. Creates new
Genetic combinations known
As genetic recombination.
Offspring may be similar in
Some ways to parents but
Will not be genetically
Identical to either of them.
DNA = deoxyribonucleic acid
Contains the genetic codes of
Life. It’s a type of protein.
Looks like a twisted ladder =
Double helix.
Composed of sugar, bases,
And phosphates subunits.
4 Bases of DNA = A , T,G & C
A always bonds with T
G always bonds with C
Always take grandma cookies
Complete the matching base
Codes. ??????????
Answer to previous slide
One strand of DNA = a
Nucleotide, is composed of
A phosphate, sugar and 2
The base codes,
of DNA ,
ATGC determine
Specific traits of
The individual.
Why is DNA the “secret to life”?
The Secret of
Replication – cells make exact
Copies of their DNA to be
Passed on to offspring
Offspring may inherit and
Make similar proteins as
Parents – this may cause
Similar traits, looks etc.
DNA has sort of a side job
it also directs and
Controls the production of
all Proteins.
Mutations – any alteration to
A gene (DNA segment) such
As an addition or deletion.
Mutations can only be passed
On to offspring if they occur
In sex cells (sperm or eggs)
Mutation examples = sickle
Cell anemia – misshaped red
Blood cells - substitution
Mutations involve the deletion
Addition or substitution of
A DNA base code
Sickle Cells
YouTube - The Eyes of Nye - Race
(Part 1 of 3)
Causes of mutations =
Mutanogetic agents =
Radiation, x-rays,UV rays
Asbestos, formaldihyde,
Exposure to dangerous
Chemicals. Mutations can
Also occur for no reason
Environment can influence
What gene is expressed.
example =
Where an animal lives can
Cause it to be a certain color
As the “wrong” color rabbits
Might be eaten by predators
Genetic Engineering –
New technology used to alter
Genetic instructions.
Selective Breeding = uses
Desirable traits that appear
To produce desirable
Product. Ex.= a plant that is
Resistant to disease
Selective breeding has
Been used by man
For many years – this is
How we have developed
All our dog breeds and many
Gene splicing – uses special
Enzymes to allow segments
Of DNA to be cut and spliced
Into other spots, results in
Controlled traits.
Biotechnology – using tech.
And biological sciences,
Ex. = using microbes to
Make cheese and using
DNA fingerprinting from
The smallest amount of
Saliva or body fluids.
Cloning – produces identical
Offspring by inserting a
Nucleus into an egg cell.
The nucleus is removed from
An egg cell and any cell
Nucleus from the desired
Clone is implanted in that
Egg cell and then developed
Usually inside a surrogate
Theraputic vs Reproductive
Theraputic = stem cell cloning –
Organisms are cloned for their
Organs and tissue use – ex grow
A new heart that can be transplanted
To save a life.
Reproductive – the whole
Organism is cloned/copied
Ex=Dolly the sheep
Gel Electrophesis – uses
To break down DNA
to identify Using a DNA
Solve crimes, determine
Karyotype = a picture of
The chromosomes of an
A karyotype can tell you the
Sex and some disorders of
The individual.
Sex is determined by the 23rd
XX = female Xy = male
In some situations karyotype
Can be done to fetus inside
The womb using the fluid
That surrounds, protects and
Cushions fetus – amniotic
Disorders – downs syndrome
= mental retardation –results
From an extra 21 chromo.
Trisomy 18
Turners syndrome
Big closing summary thing
DNA = a special protein
That makes up genes that
Are found in chromosomes
In the nucleus of all cells.
Your DNA base codes ATGC
Determine your traits.