Download DNA What is it? - demonstration456

DNA
DNA
http://www.youtube.com/watch?v=XuUpnAz5y1g
Animal Cell
The difference between:
DNA, Chromosomes and Genes.
 DNA is a long continuous strand of
genetic information.
 Genes are segments of DNA which
control the inheritance of specific
characteristics/trait.
 Chromosomes are long tightly coiled
strands of condensed DNA and
protein.
A trick to help remember:
DNA is like a long piece of string.
Genes are the knots in the string.
Chromosomes are a big coilof knots.
Another way to think of it
How can 2 meters of genetic
code fit into a body cell?
 http://learn.genetics.utah.edu/content/begin/cells/scale/
 Who wants to be a volunteer!
 If you were to uncoil a chromosome you would find over 2m
of DNA.
DNA to Chromosome
http://www.youtube.com/watch?v=5UoKYGKxxMI&feature=fvsr
What does DNA look like?
DNA is structured like a ladder that has been twisted.
This twisted shape is called a double helix.
What does DNA look like?
DNA is made up of blocks called
nucleotides.
Each nucleotide is made up of a
phosphate,
a sugar and a base.
The nucleotides are named after the
bases that they are made of, Adenine,
Thymine, Guanine, and Cytosine.
A always pairs with T.
C always pairs with G.
A trick to help remember
AT the Cricket Ground.
AT is a word. CG look similar.
DNA game
http://www.nobelprize.org/educational/medicine/dna_double_helix/
 Type “Nobel Prize DNA
game” into Google.
 Click the first link
 Play the game
 People with high scores
will win a prize!
 The game will let you make
mistakes, so remember...
A-T
C-G
One step further

Backbone (made of sugar and phosphate the vertical
part of the ladder)

Base pairs (the horizontal rungs)
made of AT – CG.

Nucleotides the building blocks of DNA are which
consist of a phosphate, a sugar and a base.
Nucleotide
Check your knowledge challenge...
 1) Where is DNA located?
 2 )What is the difference between DNA a gene and a chromosome?
 3 )Describe the structure of DNA.
 4 )What is a nucleotide? How many are there? What are they named?
 5 )Which base pairs match up?
Mix and Match
1 -DNA
3 -Chromosomes
B) Genetic material found
in every living cell. It is a
chemical compound that
carries genes and it is how
we store genetic
information in our cells
2 - Genes
A) Made of DNA and
proteins coiled tightly
together.
4 - Alleles
C) Variations of genes, ie
blue eyes, green eyes, tall,
short.
D) Sections of DNA that
control the inheritance of
certain characteristics. Ienose shape, ear lobe type,
eye colour, pea plant height
or colour.
Punnet square game
 Revision of last lesson
Type punnet square game
into Google
Select the fourth link
 http://www.mhhe.com/b
iosci/genbio/virtual_labs/
BL_05/BL_05.html
 Remember
 A dominant trait is always
represented by a capital
letter.
 A recessive trait is
represented by a small
letter.
Next lesson
Chromosomes!
Chromosomes!
 Every living thing has its
own number of
chromosomes in each
body cell, normally
occurring in matched
pairs.
 Every human cell,
(whether located in
your eyeball or your
arm, your kidney or
your blood) will have 23
chromosome pairs or 46
chromosomes in total.
What do other animals have?
 Do larger organisms have
more chromosomes?
 What organism has the
largest number of
chromosomes?
Species
Kingfisher (bird)
Elephant
Fruit fly
Human
Chimp
Dog
Snail
Onion
Number of
chromosomes
per cell
Species
Number of
chromosom
es per cell
Species
Number of
chromosom
es per cell
Kingfisher (bird)
132
Onion
16
Elephant
56
Sugar cane
80
Fruit fly
8
Wheat
42
Human
46
Chimp
48
Dog
78
Snail
52
1260
Organism with the least
Ant Myrmecia pilosula
2
Organism with the most
Adders Tongue Fern
Ophioglossum reticulatum