GENETICS
Why are we who we are?
 Where does your physical appearance come from?
Build a cell
 Use the loose materials at the side bench to
create a cell
 Include all structures you know about.
 Label all structures.
 You may work with groups up to 3 people.
 Remember all the materials you use will have to
be put away at the end or you’ll make this girl cry.
Why is genetics important?
Jellyfish
Genetically modified cat with genes
from Jellyfish
Microtubules (a protein) with genes
from Jellyfish
Genetics
 What is Genetics?
 The study of genetic transfer
 So what are Genes exactly?
 Genes are very small pieces of DNA
 Why is studying them important?
Human genome
Fun DNA facts!
 DNA from one cell is about 2 meters long
 DNA from one adult can stretch to the
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
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moon and back 6,000 times
There are 20-25 000 genes
Only 1.5% of DNA is genes
You and I are 99-99.9% identical at the
DNA level
Typing 60 words per minute for 8 hours a
day you could write the human genome in
50 years!
Why is genetics important?
 Allows us to study:
 Some hereditary diseases (Huntington’s disease)
 Cancers
 Pathogens (bacteria and viruses)
 Crime scenes!
 Allows us to create:
 Large quantities of organic molecules (Insulin for ex.)
 Vaccines
 Antibiotics
 Genetically modified organisms (GMO)
 Plants, bacteria, animals
 Also useful for traditional breeding processes
Really cool stuff!
 https://www.youtube.com/watch?v=1c-agCXZ2EU Jellyfish
 https://www.youtube.com/watch?v=0WN_YQUiWtU Glow in the dark
fish
 Why bother doing this?
http://www.slate.com/articles/video/video/2013/12/glow_in_the_dark_pig
_video_chinese_scientists_use_jellyfish_dna_to_create.html
 https://www.youtube.com/watch?v=OSx_x5FkY2w Cool animals!
Human genome
 Why do we have two copies of
each gene ?
 Where does each copy come
from?
 Think-Pair-Share
How do we know about genes?
This guy!
Gregor Mendel
 The father of genetics
 Grew and cross-bred pea plants
 Very carefully recorded all of his observations
You are a pea plant!
 Pea plant activity
 Do not open your cue cards until asked to!
Step 1:
 Obtain two cue cards from Mr. Mitchell
 I will divide the room into two groups
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
One group will be tall pea plants Stand beside your desk
One group will be short pea plants Sit down at your desk
Step 2:
 Exchange cards:
 Students who are standing will exchange 1 of their cards with someone who is
sitting
 If you are sitting you may only make one exchange
 At the end of step 2 you should have one original card and one new card.
Step 3:
 What kind of pea plant do you think you are?
Size of pea plant
Tall
Medium
Short
What is going on?
Number of pea plants
Step 4:
 Turns out you are all tall pea plants
 Everyone should be standing now because you are all tall
 Exchange at random one of your cards with someone else
 ONLY MAKE ONE EXCHANGE!
Step 5:
 What kind of pea plant are you now?
Size of pea plant
Letters on your cards
TT
Tt
tt
Number of plants
Dominant and Recessive Genes
 Why was everyone a tall pea plant after the first round of exchanges?
 Some genes are dominant, they will be displayed no matter what if present
 Some genes are recessive, they will only show up if there are two copies of them
present
 Phenotype: Observable characteristics
 Genotype: Genetic makeup
 A dominant gene will always be observed in the phenotype
 A recessive gene will only be observed when the genotype has two recessive
genes
Gregor Mendel
 Concluded there were invisible “factors” which influenced the traits of
offspring
 These factors were later called genes.
 Created several laws of inheritence
First Law of Inheritance
 Law of segregation:
 Individuals all have a pair of alleles which separate during cell division
 Offspring receive only one allele from each parent
 Allele – a single variant form of a gene (in this case you either started
with the two alleles tall tall, or short short, you had two alleles they just
happened to both be the same).
Second Law of Inheritance
 Law of independent assortment
 Genes for separate traits are passed down independent of genes for other
traits.
 If I were to add a second trait to our activity you would have needed
separate cue cards to hand one of each type randomly to someone else.
The second law is only partially true
 Remember we have 20-25 000
genes but only 23 pairs of
chromosomes, they can’t all be
independent!
Plant and animal breeding
 Historically plants and animals have been bred to gain desired traits
 Examples: (write one down)
 Horses which are larger and have better endurance
 Plants which grow more or different varieties of produce
 Plants which will both grow well in harsh conditions and are good producers
Darwin used these facts in his book The Origin of Species in his argument
for evolution.
Darwin
 In the origin of species wrote:
“Slow though the process of selection may be, if feeble man can do much by
his powers of artificial selection, I can see no limit to the amount of change,
to the beauty and infinite complexity of the co-adaptations between all
organic beings, one with another and with their physical conditions of life,
which may be effected in the long course of time by nature's power of
selection.”
How have pugs changed over time
 https://www.youtube.com/watch?v=Wz0mJW_LKsU
Modern techniques
 GMO’s
 What are GMO’s?
 https://www.youtube.com/watch?v=EzEr23XJwFY
Genetically Modified Organisms (GMO)
 GMO:
 An organism which has had its genome has been altered through genetic
engineering Example: Glow in the dark fish

 Genome:
 The total genetic make-up of an organism or cell
 Desired traits in one species are inserted into the DNA of another species
 Or genes are deleted
 Or genes over-produce compared to their “natural” counterparts
Take some notes:
 Historically plants and animals have been bred to gain desired traits
 Examples: (write one down or use another one I talked about)
 Horses which are larger and have better endurance
 Plants which grow more or different varieties of produce
 Plants which will both grow well in harsh conditions and are good producers
 Modern techniques allow for creation of genetically modified organisms
which is used to make Inuslin
Vocabulary
 Genetically Modified Organism (GMO):
 An organism which has had its genome has been altered through genetic
engineering Example: Glow in the dark fish
 Genome:
 The total genetic make-up of an organism or cell
Insulin
 Promotes uptake of glucose (sugar) from our blood to tissues
 Produced naturally in our bodies in the pancreas
 Some people do not produce enough
 Some peoples bodies stop responding properly to insulin
 This is called Diabetes
 So what do people with diabetes do?
 Inject insulin to prevent high blood-sugar
Where does the insulin come from?
 It used to come from:
Where does the insulin come from?
 About 2 tons of pig parts to produce 8 ounces of pure insulin
 Allergic reactions occurred
 Now Insulin is produced by bacteria
 All thanks to knowledge about genetics
 Cheaper to produce
 No chance of allergic reactions
GMO crops
 There are lots of commercially available crop varieties:
 Corn
 Soybean
 Golden Rice
 Genes for Vitamin A have been added
 250 000 to 500 000 vitamin A-deficient children become blind every year, half of
them dying within 12 months of losing their sight. (World Health Organization).
 Pope Francis has given his blessing to the project (go Pope Francis!)
 However…….. https://www.youtube.com/watch?v=zuc4Kf8E3SA
More notes!
 Insulin:
 Used to be made by cows
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
Allergic reactions occurred
Took a lot of resources to produce
 Now genetically modified bacteria produce it.
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No chance of allergic reactions
Lots can be made quite easily
 GMO crops are very common
GMO assignment
Assignment #1: What are GMO’s?
RE9.1 Examine the process of and influences on the transfer of genetic information and the impact of that
understanding on society past and present.
For this assignment you may work with groups of up to 3 people, or you may work alone. Your goal is to create
a poster, presentation, report, video, website or any other form of representation you feel is appropriate.
Within this format you will be responsible for:
 Outlining what a GMO is
 Pick one GMO crop I have listed on your assignment sheet
 Explain what has been modified in that crop
 Detail potential benefits as well as potential drawbacks of that crop
 State your own opinion(s) on the production of this crop and other GMO crops
You will have one class period to conduct your research, the final product is due on Tuesday September 21st.
Recall Dominant and Recessive genes
 There are lots of easily observed phenotypes in humans which display
dominant or recessive traits.
Dominant and Recessive genes in
us
 Phenotypes we can observe:
Trait
Eye colour
Earlobe
Freckles
Dimples
Chin Cleft
Hitchhikers Thumb
Widow's peak
Brown
Detached
Present
Present
Present
Absent
Present
Blue
Attached
Absent
Absent
Absent
Present
Absent
Dominant and Recessive genes in
us
Attached
Detached
Widow’s peak
No widow’s peak
Representing genes
 We use a single letter to represent specific genes.
 Dominant genes get an upper case letter
 Recessive genes get a lower case of the same letter
 For instance for the tall pea plant we used T, the other allele t is for short.
 If something (or someone) is phenotypically recessive they are two lower
case letters. (tt)
 If something (or someone) is phenotypically dominant they are either a
mix of upper and lower case or both upper case. (TT or Tt)
Dominant and Recessive genes in
us
 Fill in your charts possible Genotypes (for example I have freckles so I could be FF or Ff)
Trait
Eye colour
Earlobe
Freckles
Dimples
Chin Cleft
Hitchhikers Thumb
Widow's peak
Brown (B)
Blue (b)
Detached (E) Attached (e)
Present (F)
Absent (f)
Present (D) Absent (d)
Present (C)
Absent (c)
Absent (H) Present (h)
Present (W) Absent (w)
Class data:
Trait
Phenotypes
Eye colour
Brown (B)
Blue (b)
Earlobe
Detached (E) Attached (e)
Freckles
Present (F) Absent (f)
Dimples
Present (D) Absent (d)
Chin Cleft
Present (C) Absent (c)
Hitchhikers
Thumb
Absent (H) Present (h)
Widow's peak Present (W) Absent (w)
Genotypes
Bb or BB
bb
Ee or EE
Ee
Ff or FF
ff
Dd or DD
dd
Cc or CC
cc
HH or Hh
hh
Ww or WW
ww
Dominant and Recessive genes
 Sheep:
 Black coat is recessive
 White coat is dominant
If we were to write this out:
White coat would be either Ww or WW, black coat would be ww
Extra notes.
 Genes are represented by a single letter
 Upper case letter is used for dominant allele, lower case is used for recessive
allele

Ex. A dominant allele for hitchhikers thumb would be “H”, the recessive gene would be
“h”
 In animals coat colour is an easily identified dominant/recessive trait.
 In plants, the colour of flower
 Allele – a single variant form of a gene
Genetic disorders
 What happens when you receive the wrong number of chromosomes?
 Typically the fetus will self abort if there is an incorrect number of
chromosomes
 In some cases the fetus is still viable
 Some examples:
 Down syndrome
 XXX syndrome
 Klinefelter syndrome
 Turner syndrome
Trisomy 21 AKA Down Syndrome
 Screening of pregnant women can detect if the fetus is likely to
have down syndrome
 In the US 65% of diagnosed fetuses with Down Syndrome are
aborted
 In Europe 92%
 Tests have up to 5% false positives
 5% of the time when the test says the child will have Down
Sydrome the test is wrong!
48
Other errors
 XXY – Klinefelter syndrome
 May have cognitive developmental delays
 Not always diagnosed because of mild symptoms
 XXX – Triple X syndrome.
 May not present any symptoms

Because in all human cells only 1 x chromosome is active.
 Turner Syndrome
 1 in 2500 females affected
 Only 1 X chromosome present or part of a second one
 Average height of 4’7”
 infertility
49
Other genetic disorders
 Sickle cell anemia:
 Cells end up being a shape which can cause
blocking of blood vessels
 Can be very painful
 Cells die prematurely
 Colour blindness:
 Affects males more than females (it is
recessive on the X chromosome)
25
29
45
56
6
8
Write like the wind!
 Wrong number of chromosomes=miscarriage typically
 Extra X chromosome, or chromosome 21 can result in live births
 XXX syndrome, XXY Klinefelter syndrome

Mild symptoms
 Turner syndrome (1 X chromosome)

Infertility and short stature
 Trisomy 21 – Down syndrome


Distinct physical features
Short life expectancy and learning disabilities
Keep writing
 Colour blindness
 Found on X chromosome

Males more likely to be affected
 Sickle cell anemia
 Mis-shaped red blood cells can cause blockage of smaller blood vessels/veins
Mutations!
 https://www.youtube.com/watch?v=ZCovtVdpuIs
 Mutation:
 Mutations are changes in the genetic code of an organism or cell which can be
passed on to future generations of organisms or cells.
Mutation activity:
 Find a partner (groups of 2 only please)
 Come up and grab sheet A and sheet B (one partner gets sheet A the other
gets sheet B).
Do not look at each others paper.
 Grab a paper towel, whiteboard and marker; test your marker.
 Await further instructions.
Mutations activity part 2:
 Now that you have your whiteboards and each of you has one sheet of
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


paper either A or B:
Write down sentence 1 on your whiteboard.
Erase one of the underlined words
Pass your whiteboard to your partner.
Fill in the blank with a word you think is appropriate
Read your new sentences to each other.
 Repeat for sentence 2 but not for sentence 3.
Sentence 3:
 Write down sentence 3 and erase one of the words like before.
 Now pick a word from your noun list and circle it.
 Exchange boards. Fill your new blank with the word you circled
 Read them back to each other.
Mutations:
 This activity was meant to simulate mutations.
 Our cells are very good at repairing mutations. (sentences 1 and 2)
 Occasionally our cells have to guess how to fix mutations. (sentence 3)
The Genetic Code
 There are 4 different molecules that make up all of our DNA.
 These 4 bases are represented by four letters
 A, C, G, and T.
 When DNA replicates (is copied) a mistake is made 1/100,000 times
 This totals about 120,000 mistakes every time DNA is copied in 1 cell.
 Luckily our cells are very good at repairs and very rarely does a mistake go
unnoticed.
Mistakes happen.
 Some errors do not get fixed and are passed
down
 If multiple errors occur in a single cell line
cancer cells can emerge.
 Our bodies fight cancer cells naturally
 Cells self destruct if they know there is an
error
 If a cell has different DNA it may produce
different products which our body can
recognize as foreign.
Gene therapy
 Some virus’ can insert their DNA into our chromosomes
 This is partially why we see other species genes in our own DNA
 In gene therapy viral particles have their DNA replaced with new DNA
 This is then inserted into our cells and into our chromosomes.
Notes: DNA and mutations
 DNA is represented by a 4 letter code
 A, T, G, C
 DNA replication results in errors which mostly get fixed
 When errors do not get fixed it can result in cancer


Only if there are several errors within a single cell line
These errors can build up over time
 Cells with errors self destruct
 Our immune system also attacks cells with errors.
 Gene therapy – correct DNA is inserted into cells using viral particles
 Can cause immune reactions.
What have we learned so far?
 We have been discussing how genes are transferred
 Grab a whiteboard and make a group of 3-4 people
 Brainstorm what you have learned about genetic transfer over the last
week.
 Write down what you think are the most important things you have learned
Mitosis Overview
Interphase occurs before Mitosis begins:
 Interphase G1
 Cell growth
 DNA is not replicated yet
 Interphase S
 Synthesis of DNA
 Interphase G2 (just after S
phase)
 Cell growth continues

Cells double in size through
the course of interphase
http://www.bioweb.uncc.edu/1110Lab/notes/notes1/lab6.htm
Prophase
 Chromosomes condense

Each chromosome is made
up of two sister chromatids
 Centrosomes move to
opposite ends of the cell
 Nuclear envelope breaks
down
http://www.bioweb.uncc.edu/1110Lab/notes/notes1/lab6.htm
Metaphase
 Centrosomes attach to
chromatids
 Chromatids line up along
the centre of the cell
http://www.bioweb.uncc.edu/1110Lab/notes/notes1/lab6.htm
Anaphase
 Sister chromatids separate
 Chromatids move to opposite ends of the
cell
Telophase
 Nuclei re-form
 Chromosomes decondense
Cytokinesis
 Begins in anaphase
 Organelles (ER, golgi apparatus,
mitochondria) are divided
between the two daughter cells.
 Cell membrane pinches in the
middle resulting in two cells
Cell cycle notes
 Interphase
 Cells double in size
 DNA replicates

After chromosomes replicates it consists of two sister chromatids
 Centrosome replicates
 Prophase
 Chromatids condense
 Centrosomes move to opposite poles of the cell
 Nuclear envelope dissipates
 Mitotic spindle attaches to chromatids
 Metaphase
 Chromatids line up along the centre of the cell
 Centrosomes attach to chromatids
Cell cycle notes
 Anaphase
 Sister chromatids separate and are pulled to opposite poles
 Telophase
 Nuclei form around chromatids, chromatids begin to decondense
 Cytokenesis
 Begins in anaphase by moving organelles (mitochondria, ER, golgi etc) to
each pole
 Ends with pinching off of the cell membrane resulting in two cells
 Vocabulary:
 Mitotic spindle – fibres which help move chromatids to proper positions.
 Centrosome – connects to mitotic spindle to help pull chromatids to
opposite poles
Two options after mitosis
 Cells can re-enter the cell cycle
 The entire cycle takes around 48 hours, most of that is interphase
 Cells can go into a state called G0 (G-naught)
G0
 Cells no longer divide but are still active
 Some cells may exit this stage and divide
 Other cells will remain in this state forever
 Nerve cells for example typically do not divide
as adults
DNA damage and division
 Recall that DNA damage can result in mutations
 Most DNA damage is repaired
 Cells check their DNA in G1 to make sure there is no damaged DNA
 Cells check their DNA during interphase S for damage and errors while
replicating
 Cells check their DNA again at G2 to make sure everything replicated
properly in interphase S
 Finally cells check to make sure things are aligned during metaphase
The cell cycle
Using your microscope
 Use the lowest power (4x magnification).
 Lower the stage as far down as it will go
 Place your selected slide on the stage and secure in place
 Turn the light on and make sure the light is hitting a useful spot.
 Look through the eyepiece and move the stage up using the coarse
adjustment knob until you have an image in focus
Using your microscope
 Move to the 10x lens.
 Re-focus using the FINE ADJUSTMENT ONLY
 Once in focus move to the 40x lens
 Re-focus using FINE ADJUSTMENT ONLY
 Draw a cell which is undergoing mitosis, use the guidelines within the
textbook.
 you can pick any stage of mitosis you like, be sure to label any structures
you can see.
Team-work/ team editing
This slide is just here to remind me to talk about this!
Exemplars of student news hand-ins 2/3
Exemplars of student news hand-ins 3/3
Cheating on checkpoints
 Sometimes mutations occur which allow cells to skip the checkpoints
 This can result in uncontrolled growth (replication of cells)

Cells capable of becoming cancerous can result due to this.
Cell cycle notes
 Cells re-enter cell cycle or enter G0 (G-naught)
 Cells no longer divide but are still active
 Some cells may exit this stage and divide
 Other cells will remain in this state forever
 Nerve cells for example typically do not divide as adults
 Recall that DNA damage can result in mutations
 Several checkpoints in the cell cycle to prevent this
 Ignoring these checkpoints because of mutations can result in cancer.
Activity time!
 Step 1: Find a partner, take out your cell phone and take a picture of that
partner
Activity time!
 You have received two identical pieces of paper.
 Take a few minutes to draw a picture of yourself on one of the pieces of paper.
 Fold your papers in half
 Find a partner decide between you which will be on team 1 and which will be
on team 2.
 Line up in the middle of the room in a straight line standing next to your
partner.
Activity time!
 Move to opposite sides of the room, one person towards the front of the





room one person towards the back of the room.
Unfold your paper then refold it
Line up again in opposite orientation to the first time
Exchange papers with someone else in your line.
Move to opposite sides of the room again, one person towards the desk
side, one person towards the computer/door side.
You just completed one cycle of Meiosis
 Note that there is no exact copy of yourself in the other 3 cells.
Activity time!
 Get your two pieces of paper out again.
 Find the person in the room who has the same letters on their paper as
you, the letters will be the same but the capitalization will be different.
 Line up in a straight line in the middle of the room standing beside your
partner.
 Tear your picture in half so that you now have one letter one each half of
the picture
 Exchange half of your torn paper with your partner making sure you still
have two different letters.
 Tape your torn papers together (each partner should have ½ of their own
paper taped to ½ of their partners paper).
Activity time!
 Exchange Pieces of paper with your partner
 Team 1 move towards the computer side of the room.
 Team 2 move towards the couch side of the room.
 Unfold your pieces of paper
 Congratulations you have just completed the Mitosis cell cycle!
 The pieces of paper you hold represent the genes you carry as a chromosome.
 Note that each ‘cell’ contains an copy of you.
 Get your piece of paper with your picture back and have a seat for a few
minutes.
Meiosis
 What is Meiosis used for:
 Meiosis is used to produce sex cells
(egg and sperm in humans)
 These cells are used to produce
offspring
Meiosis Overview
Meiosis- Interphase
 Replication of DNA
 Cells grow and prepare for
Meiosis
Prophase I
 Chromosomes condense
 Homologous chromosomes pair up
 Homologous chromosomes contain the
same genes, one is from the father
(paternal), one from the mother
(maternal).
 We have 23 pairs of homologous
chromosomes
 Crossing-over occurs
Crossing over
 Some portions of the DNA from one
homologous chromosome swap with
DNA from the other homologous
chromosome
 Crossing over gives greater genetic
diversity
Metaphase I
 Homologous chromosomes line up along
the centre of the cell.
Anaphase I
 Homologous chromosomes
migrate to opposite poles of
the cell
Telophase I and
Cytokenesis
 Nucleus reforms around chromosomes
 Cell splits into two
 At this point each half of the cell has only half
the genetic material of the original cell

They are haploid
 Cells may rest after this phase and de-condense
their chromosomes
Chromosome number
 Diploid (2n) = Full complement of chromosomes found in any somatic cell of
an organism
 Haploid (n) = Half the number of chromosomes found in a diploid cell. Sex
cells have a haploid number of chromosomes.
 Somatic cell – Any cell in the body except sex cells (sperm and eggs in humans)
 In Mitosis cells are diploid (2n)
Human genome
Not done yet!
 We now have two cells, these cells are haploid (n=23)
 Each of those cells has only half the genetic material of the parental cell
 They are called haploid
 Note that the chromosomes in each cell are a mix of maternal and paternal

One cell DOES NOT get all the mothers DNA and vice versa
 Our two cells are going to divide again.
 The same steps are used as before except interphase.
 This series of steps is called Meiosis II
Prophase II
 Nuclear envelopes start to break down
 Chromosomes re-condense
Metaphase II
 Chromosomes line up along the middle
of the cell
 In the opposite orientation from Meiosis I

(Note that your diagram does not show this)
Anaphase II
 Centrosomes pull individual
chromatids to opposite sides of the
cell
 Note that because of crossing over
these two chromatids are not
identical!
Telophase II and
Cytokenesis
 Nuclear envelope re-forms
 Chromosomes de-condense
 Cell membrane cleavage results in 4
cells none of which are identical
 These cells are sex cells (egg and sperm
in humans)
Extra notes.
 Genes are represented by a single letter
 Upper case letter is used for dominant allele, lower case is used for recessive
allele

Ex. A dominant allele for hitchhikers thumb would be “H”, the recessive gene would be
“h”
 In animals coat colour is an easily identified dominant/recessive trait.
 In plants, the colour of flower
 Allele – a single variant form of a gene (b for blue eyes B for brown
eyes)
Binary Fission
 Organisms such as bacteria do not produce sexually
 They have no need of sex cells
 Bacteria also lack membrane bound organelles
 So no need to divide these between cells
 Division begins when the bacterial cells have enough nutrients
 This results in copying of DNA
 Once DNA is copied the cell simply separates the DNA to opposite sides of the
cell and starts pinching the cell wall/membrane in the middle.
Fun Facts with Mr. Fire Blanket!
 E. coli bacteria can divide every 20 minutes
under ideal conditions
 If a single E. coli cell had unlimited resources and
was left to divide uncontrolled for two days there
would be:
 48 hours * 3 divisions/hour = 144 divisions.

Every division doubles the number of E. coli
 This would result in 2143 E. coli.
 That’s 1.11 x1043 E. coli cells.
 These would weigh 7.43x1030 grams
 The earth weighs 5.972x1027 grams (thanks google!)
What do genes actually do?
 We know they determine how we look but how?
I wonder if they know
what protein is?
What is protein?
 Think (silently)
 What is protein, where have you seen or heard about it and what do you
know?
 Pair
 Talk with your neighbor about what you know.
 Share with the class
Functions of protein
 Enzymes: Help perform chemical reactions in our body
 Amylase in our saliva starts breaking down carbohydrates
 DNA repair machinery is made up of enzymes
 Structural: Give structure and support inside and outside of our cells
 Mitotic spindle aparatus for ex.
 Hair (did you count the hairs on your head Throy?)
 Cellular processes: such as cell signaling (like cells talking to each other)
 Hormones
 Cell membrane is full of proteins
Where does all this protein come from?
 Our cells make all the proteins we need
 Proteins are genetically based (Our genes determine what our proteins
are)
 This is why our genes determine our hair colour, hair is mostly protein.
 Our immune system knows which proteins belong to us and which do not.
 Most cellular processes are carried out by proteins
Causes of mutations
 UV light
 Shorter wavelength than visible
light
 Recall the four letter code of
DNA? (ATCG)
 UV light can change C’s to T’s
 UV light can also bind two T’s
together
Causes of mutations
 X-rays
 Shorter wavelength than
UV
 Cause mutations much
more readily
Causes of mutations
 Carcinogens
 Chemicals which cause
mutations and cancer
 Can have a variety of different
effects which change the DNA
bases
Causes of mutations
 Smoking
 Smoking causes 80% of lung cancers
 Many toxic chemicals which can enter
our bloodstream
 Arsenic (found in cigarettes) prevents
DNA repair
Causes of mutations
 Free radicals
 Molecules the body naturally makes
 Antioxidants found in fruits and
veggies counteract these
Eat Healthy!
Causes of mutations
 Viruses
 Insert their DNA into ours causing mutations
 Human Papilloma Virus (HPV) for instance – cause warts


Main cause of cervical cancer
Gardasil vaccine for some forms of HPV
Causes of mutations
 UV light
 X-rays
 Carcinogens
 Smoking (carcinogens)
 Free radicals
 Viruses
Activity time
 I need two volunteers
 Don’t worry everyone else is also participating
 My volunteers are cells which are trying to replicate by mitosis
 Each time they want to replicate they must bring me a pink, green and yellow
cue card.

This allows them to recruit one of you to become a new cell
 Once you are recruited you can start to replicate as well!
 Once all the possible cells (students) are used up we’ll see who has the
most cells.
Effects of mutations
 If certain genes are mutated, the proteins they produce may not work
properly
 Hormones which signal cellular growth
 Autoregulation: cells can now signal to themselves to grow
 DNA repair proteins working improperly
 Cell cycle checkpoint proteins
 Repression of cell surface proteins
 Helps evade immune system
 Prevention of apoptosis:
 Programmed cell death
Effects of mutations
 All of the mutations discussed can cause
uncontrolled cellular reproduction
 Usually more than one of these mutations is
required to cause cancer