INTRODUCTION TO GENETICS
FROM PROTEINS TO MENDEL
Rosa Macaya
16/Maig/2011
INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.1. Should we have our four child?
Activity 1.1.
I. Listen to the story and tick the words you hear
HAPPINESS
TEA INFUSION
UNHAPPINESS
BLOOD TRANSFUSION
BLOODINFUSION
BAD LUCK
GOOD LUCK
BLOODY
BLEEDING
PARENTS
GRANDPARENTS
OLDEST
DEAD
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UNLUCKY
ELDEST
ALIVE
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.1. Should we have our four child?
II. Listen to the story and take notes to draw a family tree.
Male
Female
Listen to the story and try to find out what the problem is.
I think that…………..
It could be…………..
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.1. Should we have our four child?
Activity 1.2
1.2.1. Listen to the story and find out the missing words. The words
given in activity 1.1. will help you
Should we have a
fourth
Should
we child???
have a fourth child???
When I was young I______ dreamt about having children. I’d never thought
that anything bad could happen to me. Even though my brother’s ____. He was
really ________. Yes, he always had bad luck… My parents suffered so much; it
was tough having to think about every little thing that Paul did. They couldn’t live
in peace all his life. Phone calls from the school saying he was ________. Mum
running to take him to hospital, _____ _________ plus all day-to-day stuff. It
was all quite normal to me. I grew up with all of this. But, even so, I did not
expect something like this to happen to me, to my children. Nobody told me that,
nobody asked when I first got pregnant. There was _________ all around, even
from my _______. They were so excited about becoming ____________; they
didn’t tell me that there was any possibility of there being any problem with my
child. But they didn’t tell me because they did not know the truth about their
own son. Poor Paul. He died years ago from AIDS, something to be ashamed of.
It wasn’t Paul’s fault. Poor Paul… all his short life affected by what he had
inherited. He didn’t choose to die; death found him… got into somebody’s _____.
Yes, somebody’s blood. How unlucky was that! Poor Paul… But nobody told me
that my own kids could have the same problem as my ______ brother, my
beloved brother. Not even the doctors told me anything. They didn’t ask me
about my family __________.
(Part I (1’46’’)28 lines)
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.1. Should we have our four child?
1.2.2
Listen to the story. Fill in the gaps and complete the family
tree you drew in activity 1.1
So I had my _____ _____. We all felt so happy. And my ______, the lovely
_____, and no problem either. But our luck seemed to run out when my
________ ___ was born. Just arrived in the world and he started to suffer. His
birth was very traumatic. I lost a lot of blood, hours and hours and my poor baby
was still bleeding. My ______ prayed. I was scared; I could not see him until
days later. My _______ could, but he didn’t tell me anything. Well, I don’t think
he knew what to say. When our son was diagnosed with “haemophilia” I didn’t
know what it meant. In hospital we were asked about our family background and
then I discovered the truth about ____. I couldn’t understand why my _______
hadn’t told me the truth about Paul’s illness, even about his death. But I don’t
think they were sure about anything. I feel sorry for them now, but then I was
very disappointed and I blamed them for my baby’s disease. If had known about
this before, then certainly I wouldn’t have had the kid. But we did not know
anything!
(Part II, (1’13’’)15 lines)
1.2.3 Listen to the story. Fill in the gaps and write two sentences
summarising the story.
It took a while for us to understand ___________. With a lot of help from all
the hospital staff we learnt to cope with it and how to bring up our
___________ child. Things have changed a lot, new products have been
discovered and I hope my youngest child’s life will be easier than his uncle’s.
Now, our Tom is already 6 years old and he seems to be controlling his
________ episodes.
I don’t know if I am a _______ or not. Neither does my husband. Though
everything points to the ____ coming from my family. I have learnt a lot about
___________. If only my parents had known more…, but I don’t think that it
was their fault. They didn’t know anything and the doctors didn’t tell them
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.1. Should we have our four child?
anything; they probably thought they wouldn’t understand. It is pity to live in
such ignorance! Always believing that life is a kind of fate… But I don’t want to
live like that. I’d like to have a fourth child and I want to know what the chances
are of having a “healthy” child in spite of my ____ history. I have heard about
being able to find out, but I am not sure.
Science should be there to help to fight against our “bad” _____, shouldn’t it?
(Part III, (1’15’’) 19 lines)
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.1. Should we have our four child?
SHOULD WE HAVE A FOURTH CHILD???
When I was young I always dreamt about having children. I’d never thought that
anything bad could happen to me. Even though my brother’s dead. He was really
unlucky. Yes, he always had bad luck… My parents suffered so much; it was tough
having to think about every little thing that Paul did. They couldn’t live in peace
all his life. Phone calls from the school saying he was bleeding. Mum running to
take him to hospital, blood infusions plus all day-to-day stuff. It was all quite
normal to me. I grew up with all of this. But, even so, I did not expect something
like this to happen to me, to my children. Nobody told me that, nobody asked
when I first got pregnant. There was happiness all around, even from my
parents. They were so excited about becoming grandparents; they didn’t tell me
that there was any possibility of there being any problem with my child. But they
didn’t tell me because they did not know the truth about their own son. Poor
Paul. He died years ago from AIDS, something to be ashamed of. It wasn’t Paul’s
fault. Poor Paul… all his short life affected by what he had inherited. He didn’t
choose to die; death found him… got into somebody’s blood. Yes, somebody’s
blood. How unlucky was that! Poor Paul… But nobody told me that my own kids
could have the same problem as my eldest brother, my beloved brother. Not
even the doctors told me anything. They didn’t ask me about my family
background.
So I had my first child. We all felt so happy. And my second, the lovely Helen,
and no problem either. But our luck seemed to run out when my youngest son was
born. Just arrived in the world and he started to suffer. His birth was very
traumatic. I lost a lot of blood, hours and hours and my poor baby was still
bleeding. My mother prayed. I was scared; I could not see him until days later.
My husband could, but he didn’t tell me anything. Well, I don’t think he knew
what to say. When our son was diagnosed with “haemophilia” I didn’t know what
it meant. In hospital we were asked about our family background and then I
discovered the truth about Paul. I couldn’t understand why my parents hadn’t
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.1. Should we have our four child?
told me the truth about Paul’s illness, even about his death. But I don’t think
they were sure about anything. I feel sorry for them now, but then I was very
disappointed and I blamed them for my baby’s disease. If had known about this
before, then certainly I wouldn’t have had the kid. But we did not know anything!
It took a while for us to understand haemophilia. With a lot of help from all the
hospital staff we learnt to cope with it and how to bring up our haemophilic
child. Things have changed a lot, new products have been discovered and I hope
my youngest child’s life will be easier than his uncle’s.
Now, our Tom is already 6 years old and he seems to be controlling his bleeding
episodes.
I don’t know if I am a carrier or not. Neither does my husband. Though
everything points to the gene coming from my family. I have learnt a lot about
haemophilia. If only my parents had known more…, but I don’t think that it was
their fault. They didn’t know anything and the doctors didn’t tell them anything;
they probably thought they wouldn’t understand. It is pity to live in such
ignorance! Always believing that life is a kind of fate… But I don’t want to live
like that. I’d like to have a fourth child and I want to know what the chances are
of having a “healthy” child in spite of my gene history. I have heard about being
able to find out, but I am not sure.
Science should be there to help to fight against our “bad” genes, shouldn’t it?
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.1. Should we have our four child?
Activity 1.2.1.
Read the following text and put the names of the family member.
Compare the information you have written on the pedigree chart in
activity
1.1.1.
Paint
in
a
different
colour
the
members
with
haemophilia.
Mrs Ann Drinkwater, born Pennymann, is a 38 years old woman with
a family history of haemophilia A. She had got a five years older
brother, Paul, who died 10 years ago after getting AIDS from a
contamined plasma infusion. She does not have further information
about other members of her family. Mrs Drinkwater’s husband,
John is 40 years old and there are not haemophilia traits in his
family. They have three children, the eldest is 12 years old called
Matthew, Helen is 10. Both of them are not haemophilic. The
youngest, Tom is 6 years old and he is haemophilic.
Ann and John Drinkwater would like to have a fourth child and they
have applied to a Genetic Cabinet to know the probability of having
another child with the disease and if there is a possibility to avoid
100% sure that the inheritance of the haemophilia using Genetic
Therapy.
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.2. Making posters!
Activity 1.2.2. Making a poster
Information about Haemophilia
• Causes
Haemophilia is a sex-linked disorder. Its gene is in chromosome sexual X. Since
males (XY) have only one X chromosome, so only one copy of the gene placed in
this chromosome, if the gene is they will be affected with the disease. Females
have two X chromosome (XX) only will have the disease when they have the gene
in both (rare). The probability of a woman having the disease is very low, though
possible. That would happen if both father and mother had the affected
haemophilic gene. Frequently female are only carriers because this gene is
recessive in front the normal gene. That is why the have the ability to pass the
gene on to their offspring but are not affected with the illness themselves.
• Types
There are two types of haemophilia, A and B. Haemophilia A involves a mutation
in the factor (protein) VIII blood clotting factor gene and haemophilia B
involves a mutation in the factor IX blood clotting factor gene. Both mutations
do not let the process of blood clotting happen, as it normally should.
• Symptoms
Include internal bleeding, blood in stool and urine, frequent nosebleeds, easy
bruising, and bleeding into muscles and joints that leads to chronic arthritis;
bleeding in the rain External bleeding could appears if the skins is broken by a
scrape, cut or abrasion.
• Therapy
There is not cure for haemophilia; it can be controlled with regular injections of
the deficient clotting factor, i.e., factor VIII in haemophilia A. In western
countries, common standards of care fall into two categories: prophylaxis or ondemand. The first one involves the infusion of clotting factor in order to keep
clotting levels sufficiently high to prevent spontaneous bleeding episodes. Ondemand treatment involves treating bleeding episodes once they arise.
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.2. Making posters!
•
Collateral problems related to haemophilia therapy
As a direct result of the contamination of the blood supply in the late 1970’s and
early 80’s with virologic agents such as HIV (Human Immunodeficiency Virus)
and Hepatitis new methods were developed in the production of clotting factor
products. The initial response was to heat treat (pasteurize) plasma-derived
concentrate, followed by the development of monoclonal factor concentrates
grown to inactivate any viral agents. More recently, recombinant factors
products (which are typically cultured in Chinese hamster ovaries and involve
little, if any contact with human plasma products) have become available and are
widely used in wealthier western countries. These products are quite safe but
also very expensive and not usually available in developing countries and
sometimes are even difficult to find in developing countries.
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.2. Making posters!
Information about AIDS
• What does “AIDS” mean?
AIDS stands for Acquired Immune Deficiency Syndrome:
Acquired means you can get infected with it
Immune Deficiency means a weakness in the body’s system that fights
diseases.
Syndrome means a group of health problems that make up a disease.
• Causes
AIDS is caused by a virus called HIV, the Human Immunodeficiency Virus. If
you get infected with HIV, your body will try to fight the infection. It will
make “antibodies,” special molecules to fight HIV.
A blood test for HIV looks for these antibodies. If you have them in your
blood, it means that you have HIV infection. People who have the HIV
antibodies are called “HIV-Positive.” Fact Sheet 102 has more information
on HIV testing.
Being HIV-positive, or having HIV disease, is not the same as having AIDS.
Many people are HIV-positive but don’t get sick for many years. As HIV
disease continues, it slowly wears down the immune system. Viruses,
parasites, fungi and bacteria that usually don’t cause any problems can make
you very sick if your immune system is damaged. These are called
“opportunistic infections.” See Fact Sheet 500 for an overview of
opportunistic infections.
• How do you get AIDS?
You don’t actually “get” AIDS. You might get infected with HIV, and later
you might develop AIDS. You can get infected with HIV from anyone who’s
infected, even if they don’t look sick and even if they haven’t tested HIVpositive yet. The blood, vaginal fluid, semen, and breast milk of people
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.2. Making posters!
infected with HIV has enough of the virus in it to infect other people. Most
people get the HIV virus by:
having sex with an infected person
sharing a needle (shooting drugs) with someone who’s infected
being born when their mother is infected, or drinking the breast milk of
an infected womaN
Getting an infusion of infected blood used to be a way people got AIDS,
but now the blood supply is screened very carefully and the risk is
extremely
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.3. Making live possible...from DNA to Proteins
Review from Molecular Genetics
Activity 1.3.1
Look at the following picture…
“The Central Dogma of Molecular Biology: From DNA to RNA to Protein,,
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.3. Making live possible...from DNA to Proteins
Now…………
From the single DNA strand below, write the complementary
5’ .. t a c t a a c g t t t g t a c a a a c c g g a a a t t .. 3’
............………………………………………………………………………………………………………………….
then write the mRNA
mRNA
5’ ………………………………………………………………………………...................…………………… 3’
Look at the pictures below and write the correct name in each label
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.3. Making live possible...from DNA to Proteins
And now……….. with the help of the Genetic Code Table, translate the
RNA nucleotides’ sequence to a polypeptide sequence
You have made a protein!!!!
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.3. Making live possible...from DNA to Proteins
Activity 1.3.2
Mutations
WHAT WILL HAPPEN IF……..
…….. we change a pair nucleotides from the DNA strand….
t a c t a a c g t t t g t a c a a a c c g g a a a t g c t
.
State a hypothesis saying what could happen if you write
“aa” instead
the “tt”. You can start the hypothesis…
“If I write aa, in the place of “tt” then the mRNA will be “aa” and then
………………………………………....................................................................................................
Now think of a “way” to prove your hypothesis
Write down the conclusion.
If the nucleotides’ sequence change, ......................................................................
.
...........................................................................................................................................
Now, try to do another mutation. In this case try to delete a pair
nucleotides from the DNA strand…….
Predict what will happen…. And prove it!
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.4. Once upon a time playing with pea plants
Activity 1.3.2.
Let’s
SCIENTIFIC METHOD
and
to
relate
Haemophilia
(lack
of
an
appropriate protein) and inheritance (DNA).
Let’s work all together to write a hypothesis about this relationship and
all the steps to prove or reject our hypothesis!!
We are going to follow all the steps from the scientific method:
1. Problem – (What are you trying to figure out? Write this in the form of a
question.)
2. Hypothesis – (What do you think you are going to find out?)
3. Materials and procedure (List the materials you will use in the experiment.)
4. Results – What did you observe when you performed the experiment?
5. Conclusion – From what you observed, how would you answer your original
question?
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.4. Once upon a time playing with pea plants
Activity 1.4.1
a) First read your text and fill in the corresponding part of the table
below.
b) Make 3 people group (A,B&C), share the information from your text
and fill the rest of the table.
A
Date of birth
Father’s job
Grandfather’s job
Why did he have to stop studying?
Where did he continue his studies?
What did he do in Vienna?
What plant did Mendel mainly work
with?
B
What did he discover about tall plants?
What did he discover about short
plants?
What resulted from crossing tall and
short plants?
How many plants did he use?
How many years did it take?
What was his first law called?
What was his second law called?
C
How many basis laws of heredity did he
uncover?
Did he become famous in his life?
Why (not)?
When did he die?
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.4. Once upon a time playing with pea plants
What happened in 1900?
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 1
Lesson 1.4. Once upon a time playing with pea plants
Activity 1.4.2. Testing the text
Choose the correct option
1) Gregor Mendel was:
a)
an English gardener who grew pea plants
b)
an unknown Central European monk
c)
an early 20th century Dutch biologist who carried out genetics
research
2) Which of the following statements is true about Mendel?
a) His discoveries concerning genetic inheritance were accepted by
the scientific community
b) He believed that genetic traits of parents would usually blend in
their children.
c) He made statistical analysis in his breeding experiments
3) Mendel believed that the traits of the pea plants are determined by
the:
a)
hereditary units or factors from both parents
b) hereditary units or factors from one parent
c) health of the plant during the pollination
4) Mendel discovered that:
a) short plants produced only short offspring
b) tall plants produced only tall offspring
c) short plants produced both, tall and short offspring
5) Mendel's law of independent assortment states that:
a) each pair of genes is inherited independently of all other
pairs.
b) each pair of genes is inherited dependently of all other pairs.
c) only a gene is inherited independently of all other
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Unit 2
Student worksheets
Lesson 2.2. Swimming with Mendel’s laws
Activity 2.1.1. Hot seats
One of you plays Mendel’s role. Ask “this” Mendel questions about his
findings.
Activity 2.1.2. Genetic world words
a) Warming up!
Find out 15 of 15 words were placed into the puzzle.
R
H
G
E
S
G
E
Y
T
N
H
W K
J
P
D
K
N
V
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F
P
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J
C
E
I
W L
U
O
U
I
Q
Q
E
A
T
H
D
T
D
B
K
R
U
G
R
K
Q
R
M
R
P
N
E
O
Q
H
E
W J
P
K
T
G
O
A
N
H
R
M
K
G
T
W W S
H
J
M
F
P
G
M
O
I
Z
Z
Q
V
J
F
Z
O
J
P
A
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Z
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I
W Q
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W C
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M
V
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CHROMOSOME
DOMINANT
EGG
HETEROZYGOUS
HOMOZYGOUS
HYBRID
MITOSIS
Rosa Macaya
OFFSPRING
PURE
RECESSIVE
GAMETE
GENE
MEIOSIS
SPERM
TRAIT
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
b) Definition Team Game
Word Cards (SM): Look at the set of cards you have. Listen to the
teacher and match the sentences teacher reads out and look for the
suitable word from your set. When you found it hand up.
c) Genetic Terminology Crossword
Across
1
Opposite of recessive
Down
2 Different form of a gene
4 Section of DNA
3 Opposite to pure-breeding
5 Rewriting DNA's message
4 Combination of alleles
7 The first cell
6 Proteins factory
9 Humans have 23 pairs
8 Appearance of an organism's trai
(10 of 10 words were placed into the puzzle).
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Created by Puzzlemaker at DiscoveryEducation.com
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
d) Fill in the gaps: choose the correct word
1.
Gregor
, the "father of genetics" (Mendel/Darwin)
2. The first
generation is the offspring of a cross between
parents that are pure for a given trait.
(Hybrid/Heterozygous/Homozygous-pure)
and recessiviness. (blending/dominance)
3. The principle of
(phenotype/genotype)
4. The outward expression or appearance:
5. Cross that involves parents that differ in TWO traits.
(dihybrid cross/ Monohybrid cross)
(heredity/genetics)
6. The study of heredity:
7. An alternate form of a gene:
8. The Principle of
(allele/factor)
Assortment (dependent/independent)
9. Having non identical alleles (not pure; ex. Aa):
(heterozygous/homozygous)
10. Having identical alleles (pure, ex. AA):
(heterozygous/homozygous)
11. Square used to determine probability and results of cross:
(Punnett/Mendel)
12.The allele that is masked or covered up by the dominant allele:
(recessive/dominant)
13. The genetic make-up or an organism (Tt):
(recessive/dominant)
14. A cross that involves ONE pair of contrasting traits:
(test cross/ dihybrid cross)
15. The plants Mendel did his studies on:
(pea plants/peas plants)
16. The likelihood that an event will happen:
(probability/chance)
17. When neither allele is dominant (they are both expressed):
(codominant/recessiviness)
18. Principle of
states that alleles separate when gametes are
formed.(segregation/separation)
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
Activity 2.2.1. Simple Genetics Practice Exercises
1. For each genotype, indicate whether it is heterozygous (HE) or
homozygous (HO)
AA
Ee
Ii
Mm
Bb
ff
Jj
nn
Cc
GG
kk
OO
Dd
HH
Ll
Pp
2. For each of the genotypes below, determine the phenotype.
Purple flowers are dominant to white
Brown eyes are dominant to blue eyes
flowers
PP ____________
BB ___________
Pp ____________
Bb ___________
pp ____________
bb ___________
Round seeds are dominant to wrinkled
Short tails are recessive
(long tails dominant)
RR ____________
TT _______________
Rr ____________
Tt _______________
rr ____________
tt ________________
3. For each phenotype, list the genotypes. (Remember to use the letter of
the dominant trait)
Straight hair is dominant to curly.
Pointed heads are dominant to round
heads.
_______ straight
________ pointed
_______ straight
________ pointed
_______ curly
________ round
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
4. Set up the square for each of the crosses listed below. The trait being
studied is round seeds (dominant) and wrinkled seeds (recessive)
Rr x rr
What percentage of the
offspring will be round?
What percentage of the
Rr x Rr
offspring will be round?
What percentage of the
RR x Rr
offspring will be round?
Practice with Crosses.
5. A TT (tall) plant is crossed with a tt (short plant).What percentage of
the offspring will be tall?
6.
A Tt plant is crossed with a Tt plant. What percentage of the
offspring will be short?
7. A heterozygous round seeded plant (Rr) is crossed with a homozygous
round seeded plant (RR). What percentage of the offspring will be
homozygous (RR)?
8. A homozygous round seeded plant is crossed with a homozygous wrinkled
seeded plant. What are the genotypes of the parents?
What percentage of the offspring will also be homozygous?
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
9. In pea plants purple flowers are dominant to white flowers. If two white
flowered plants are crossed, what percentage of their offspring will be
white flowered?
10. A white flowered plant is crossed with a plant that is heterozygous for
the trait. What percentage of the offspring will have purple flowers?
11. Two plants, both heterozygous for the gene that controls flower colour
are crossed. What percentage of their offspring will have purple
flowers?
What percentage will have white flowers?
12. In guinea pigs, the allele for short hair is dominant. What genotype
would a heterozygous short haired guinea pig have?
What genotype would a pure breeding short haired guinea pig have?
What genotype would a long haired guinea pig have?
13. Show the cross for a pure breeding short haired guinea pig and a long
haired guinea pig
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
What percentage of the offspring will have short hair?
14. Show the cross for two heterozygous guinea pigs.
What percentage of the offspring will have short hair?
What percentage of the offspring will have long hair?
15. Two short haired guinea pigs are mated several times. Out of 100
offspring, 25 of them have long hair. What are the probable genotypes
of the parents? ___ x ___ Show the cross to prove it!
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
Activity 2.2.2. Two traits genetics crosses
In rabbits, grey hair is dominant to white hair. Also in
rabbits, black eyes are dominant to red eyes
GG = grey hair
BB = black eyes
These letters represent the
Gg = grey hair
Bb = black eyes
genotypes of the rabbits:
gg = white hair
bb = red eyes
1. What are the phenotypes (descriptions) of rabbits that have the
following genotypes?
Ggbb _________________ ggBB ______________________
ggbb _________________ GgBb ______________________
2. A male rabbit with the genotype GGbb is crossed with a female rabbit
with the genotype ggBb the square is set up below. Fill it out and
determine the phenotypes and proportions in the offspring.
Gb
Gb
Gb
Gb
gB
gB
gb
gb
How many out of 16 have grey fur and black eyes?
How many out of 16 have grey fur and red eyes?
How many out of 16 have white fur and black eyes?
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
How many out of 16 have white fur and red eyes?
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
3. A male rabbit has the genotype GgBb. Determine the gametes produced
by this rabbit (the sperm would have these combinations of alleles) Hint:
there are 4 combinations.
4. A female rabbit has the genotype ggBb. Determine the gamets (eggs)
produced by this rabbit.
5. Use the gametes from 4 and 5 to set up the punnet square below. Put
the female's gametes on the top and the male's gametes down the side.
Then fill out the square and determine what kind of offspring would be
produced from this cross and in what proportion.
gB
gb
GB
Gb
gB
gb
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.3. Swinging with Mendel’s laws exceptions
Activity 2.3.1
Co-dominance, Intermediate Expression and Multiple Allele
If there are only two alleles involved in determining the phenotype of a
certain trait, but there are three possible phenotypes, then the
inheritance of the trait illustrates either incomplete dominance or
codominance. The incomplete dominance is also known as intermediate
expression, and the phenotype is shown as a blend of the parental
phenotypes. Codominance phenotype shows both traits, ie. From a black
and white, the offspring phenotype is black with white spots.
1. Practice setting up keys for the phenotypes listed in each set. Remember
that the "medium" trait must always be heterozygous.
a) Birds can be blue, white, or white with dark-blue feathers.
b) Flowers can be white, pink, or red.
c) A
can have curly hair, spiked hair, or a mix of both curly and spiked.
d) A
e) A
Rosa Macaya
can be tall, medium, or short.
can be spotted, black, or white.
IES Pobla de Segur
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.3. Swinging with Mendel’s laws exceptions
2. Now, can you figure out in the above list, which of the examples
represent codominant traits and which are incomplete.
When there are 4 or more possible phenotypes for a trait, then more
than 2 alleles for that trait must exist in the population but individuals
have only two of those alleles. That happens because individuals have
only two biological parents. We inherit half of our genes (alleles) from
the mother and the other half from the father, so we cannot have
more tan two alleles for every trait in our phenotype. An example of
multiple allele inheritance is human blood type. Blood type
exists
as
four possible phenotypes: A, B, AB, and O. there are 3 alleles for the
gene that determines blood type. The allele for O (i) is recessive to
the alleles for A and B. The alleles for A and B are codominant. The
alleles are noted as i, IA
and IB
3. Mrs. Drinkwater is blood type A and her mother is 0. Her children are
o, B and A. Find out what Mr Drinkwater’s blood group could be.
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.3. Swinging with Mendel’s laws exceptions
Activity 2.2.3. Genetics of Sex Determination
In
humans
the
genetic
determination
of
sexual
identity
involves
chromosomes. Humans have 46 chromosomes, 44 of these chromosomes pair
together to make 22 pairs of homologous chromosomes (autosomes); the
other 2 chromosomes are different, because they are involved in determining
the sex. They are called sex chromosomes (XX/XY). Males have an X and a Y
chromosome (XY), and females have two X chromosomes (XX). It is known
that it is the presence of the Y chromosome that makes the individual male.
Your knowledge of meiosis and fertilization provides the basis for
understanding the inheritance of X and Y chromosomes. During meiosis in a
female, the two X-chromosomes separate, so each egg has a single Xchromosome. In males, even though the X and the Y-chromosomes are very
different, they can nevertheless pair with each other and separate from
each other during meiosis. This means that males produce two kinds of
sperm; half have an X chromosome
and half have a Y chromosome.
a) What will be the sex of a child produced when an egg is fertilized by a
sperm that has a Y chromosome?
What type of sperm must fertilize an egg to result in a female child?
b) Draw a Punnett Square which shows the inheritance of the sex
chromosomes. Use X to indicate an egg or sperm with an X chromosome
and Y to indicate a sperm with a Y chromosome.
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.3. Swinging with Mendel’s laws exceptions
c) Based on this Punnett Square, what percent of children would you expect
to be male?
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.4. Let’s have children!...and something else
Activity 2.2.4. Sex-linked Traits
In humans, the X chromosome carries some genes that are not found in the Y
chromosome. Inheritance of the phenotypic traits determined by the genes
located in these chromosomes is therefore linked to the sex of the person.
The X chromosome carries other genes which are not associated with
determination of sex. One of these genes codes for a protein called blood
clotting factor. Mutations can occur in this gene resulting in a blood protein
that cannot clot the blood properly. This disease is known as haemophilia.
Haemophilia Notation: XH chromosome with normal clot factor and Xh
In humans, haemophilia is a sex linked trait. Females can be normal, carriers, or
have the disease.
Males will either have the disease or not (but they won’t ever be carriers)
Female normal: XHXH
Female carrier: XhX
Female haemophiliac: XhXh
Male normal: XY
Male haemophiliac: XhY
Show the cross of a man who has haemophilia with a woman who is a
carrier. Draw the cross in the Punnett square.
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.4. Let’s have children!...and something else
What is the probability that their children will have the disease?
A woman who is a carrier marries a normal man. Show the cross. What is
the probability that their children will have haemophilia?
What sex will a child in the family with haemophilia be?
A woman who has haemophilia marries a normal man. How many of their
children will have haemophilia, and what is their sex?
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.4. Let’s have children!...and something else
Activity 2.4.1.
LET’S HAVE CHILDREN!
What will our children look like?
Your teacher will give you an envelope with a set of 4 X 2
chromosomes. The chromosomes are in different colours and present
different alleles.
Look at the chromosomes you have and fill in the chart with your
phenotype and genotype.
Simulate meiosis by tossing a coin. If heads, take chromosome X, if
tails chromosome X‘.
Now work with your partner and take your simple chromosome and
match it with your partner’s simple chromosome. You both have your
first child.
Read and write your child’s phenotype and genotype. Repeat the
process three or four more times.
Activity 2.4.2. Genetic Report
Work in groups of 3-4 students. Each group should write a genetic
report for the Drinkwater family.
Find out the information needed and write it down in the table.
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.4. Let’s have children!...and something else
Mr & Mrs. Drinkwater: Genetic Report
Part I: The Drinkwater Family’s pedigree.
Part II: The Drinkwater Family's Haemophilia
Part III: Information about Haemophilia
To finish the report:
You will be divided into two groups: the Drinkwaters and the
Geneticists.
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INTRODUCTION TO GENETICS
From Proteins to Mendel
Student worksheets
Unit 2
Lesson 2.4. Let’s have children!...and something else
Your aim is to answer Mrs Drinkwater’s question.
(Key: As “geneticists and applying all you know about genetics find out
possible solutions to have a child not suffering from haemophilia in order to
tell the Drinkwaters)
Final activity
Role Play game: Let’s discuss!
You will be divided into two groups to discuss the use of biotechnology
in society, the ethical/moral implications of their use, etc…
One group is FOR the use of biotechnology, the other AGAINST.
First, work in your group to decide on why you are for or against
(remember, these don’t have to be your real opinions). Make some notes.
Now, as a whole class, you will have a debate. Do not be afraid to express
your opinion and try to argue or justify it.
Each group will choose a secretary which will summarize your opinions.
When the discussion is over write them in the Venn Diagram below:
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