Download Teaching notes

INTRODUCTION TO GENETICS
FROM PROTEINS TO MENDEL
Rosa Macaya
16/Maig/201
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.1. Should we have our four child?
INTRODUCTION AND RATIONALE
A fictional story is used to introduce the topic in order to relate our topic with
everyday life.
The text has been written using grammar structures according to
the age and knowledge of the students. They are aged 17-18 and will probably have
quite a good English background.
As the text is quite long it is divided into three parts, and the activities are also
split.
The activities progress in complexity, moving from LOT to HOT. Students are not
expected to understand everything the first time they listen. The overall aim of
the activity is for students to begin to question the role of genes, to get them
interested in why the situation arises, and what might be able to be done about it.
Lesson Length: 90 minutes
Activity 1.1.
Resources: Worksheet 1/audio
I Listen and tick
Give out Worksheet 1 and tell students to listen to the text and tick the words
they hear.
Give students time to check what they have ticked in pairs before moving to the
next part.
Tell students they will be able to check their answers later.
II Family tree
Focus students’ attention on Part II and get them to fill in the family tree.
Rosa Macaya
IES Pobla de Segur
2
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.1. Should we have our four child?
Give students time to check in pairs what they have written before moving to the
next part.
Tell students they will be able to check their answers later.
III Identify the problem. Get students to listen and then complete the
sentence starters
Give students time to check in pairs what they have written.
Tell students they will be able to check their answers later.
Activity 1.2.
Resources: Worksheets 1&2/audio
For each part, students listen to the text and fill in the gaps.
They also add to their notes on Worksheet 1.
After each section, they check in pairs.
Check the answers in plenary after each section/at the end of the three parts.
Help students with key vocabulary (suggest which words here).
Give students the complete text at the end.
Rosa Macaya
IES Pobla de Segur
3
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.1. Should we have our four child?
Activity 1.1.
KEY
I. Listen to the story and tick the words you hear
HAPPINESS
TEA INFUSION
UNHAPINESS
BLOOD TRANSFUSION
BAD LUCK
BLOODY
GOOD LUCK
BLOODINFUSION
UNLUCKY
BLEEDING
PARENTS
GRANDPARENTS
OLDEST
DEAD
ELDEST
ALIVE
II. Listen to the story and take notes to draw a family tree.
III. Listen to the story and try to find out what the problem is.
Rosa Macaya
IES Pobla de Segur
4
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.1. Should we have our four child?
Activity 1.2.
KEY 1.2.1. Listen to the story and find out the missing words. Help
yourself from the words given in activity 1.1.
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.
Rosa Macaya
IES Pobla de Segur
5
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.1. Should we have our four child?
(Part I (1’46’’)28 lines)
KEY 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 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 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)
KEY 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 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
Rosa Macaya
IES Pobla de Segur
6
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.1. Should we have our four child?
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?
(Part III, (1’15’’) 19 lines)
Rosa Macaya
IES Pobla de Segur
7
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.1. Should we have our four child?
TAPESCRIPT
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.
(Part I (1’46’’)28 lines)
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 told me the truth about Paul’s illness, even about his death. But I don’t
Rosa Macaya
IES Pobla de Segur
8
INTRODUCTION TO GENETICS
From Proteins to Mendel
Unit 1
Teaching Notes
Lesson 1.1. Should we have our four child?
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)
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?
(Part III, (1’15’
Rosa Macaya
IES Pobla de Segur
9
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.2. Making posters!
INFORMATION AND RATIONALE
This lesson’s aim is to give more information about the family in order to work a
little more with the pedigree chart and about the family background.
The second activity objective is to learn a bit about the two illnesses cited in the
story. Students will learn more specific vocabulary (language of and language for)
which it will be needed for the next lesson’s activities.
The third aim is to practice orally presentations and peer evaluation.
Lesson Length: 2 hours
Activity 1.2.1. Working the pedigree chart
Resources: Student worksheet
Tell students how to read a pedigree chart and the meaning of the figures. (round:
females/square: males). When a genetic disease is present it should be marked, ie a
different colour. So in this pedigree students colour PAUL and TOM in red.
Students read the text and put the names of the family members. Compare the
information you have written on the pedigree chart in activity 1.1.1. Colour in a
different colour the members with haemophilia.
Activity 1.2.2. Making a “mind map” poster
Resources: Student worksheet and card, colours, pictures, (material to
make a poster…)
There are two descriptive texts blocs: one about haemophilia and the other about
AIDS. The information about each disease is divided into different parts (causes,
Rosa Macaya
IES Pobla de Segur
10
INTRODUCTION TO GENETICS
From Proteins to Mendel
Unit 1
Teaching Notes
Lesson 1.2. Making posters!
symptoms, types, therapy…). This information has to be summarized and put in a
mind map.
Procedure:
Teacher divides up the students into two groups A and B.
Working alone, students in Group A read the information about haemophilia and
highlight the main information. Then students in groups make a poster with
drawings, pictures and short texts describing the information in the text.
Group B will do the same but about AIDS.
When the posters are finished put them on the wall.
Each group will explain about the disease they have worked out. All members have
to speak.
At the end each group will give an oral feedback (peer evaluation) following these
criteria:
• Positive point’s poster layout, clearly explanations, voice, eye contact…
• To improve:
Rosa Macaya
“
“
“ “
“
”
“ ”
“
”
“
IES Pobla de Segur
11
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.2. Making posters!
Activity 1.2.1.
KEY
Read the following text and put the names of the family members.
Compare the information you have written on the pedigree chart in
activity
1.1.1.
Colour
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.
Rosa Macaya
IES Pobla de Segur
12
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
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
is placed in this chromosome, if the gene is present, then they will be
affected with the disease. Females have two X chromosome (XX) and 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 females are only carriers because this gene is recessive in front
of the normal gene. That is why they 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 lead to chronic arthritis;
bleeding in the rain. External bleeding could appear if the skin is broken by a
scrape, cut or abrasion.
• Therapy
There is no cure for haemophilia, but 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 on-demand. The first one involves the infusion of clotting
Rosa Macaya
IES Pobla de Segur
13
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.2. Making posters!
factor in order to keep clotting levels sufficiently high to prevent
spontaneous bleeding episodes. On-demand treatment involves treating
bleeding episodes once they arise.
•
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.
Rosa Macaya
IES Pobla de Segur
14
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
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.”
• 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 HIVRosa Macaya
IES Pobla de Segur
15
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.2. Making posters!
positive yet. The blood, vaginal fluid, semen, and breast milk of people 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.
Rosa Macaya
IES Pobla de Segur
16
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.3. Making live possible...from DNA to Proteins
INTRODUCTION AND RATIONALE
The main aim of this lesson is for students to be able to apply their previous
knowledge about Molecular Genetics to understand the causes of haemophilia.
Students already know from lesson 2 more about the disease and they have to find
out how it could happen from a deeper molecular point of view (DNA mutation) in
order to link the facts with Mendelian Genetics later on.
The activities progress from general and theoretical facts to the haemophilia as a
consequence of a mutation.
The used of the Scientific Method is an aim in this lesson as well.
Lesson Length: 3 hours
Resources: Power Point: Molecular Genetics and Student Worksheet
Pre-Activity:
Power Point to review Molecular Genetics: the topics and some examples.
Try to ENGAGE students’ interest through some interactive tasks (asking guessing
questions…)
Activity 3.1. and 3.2.
Give students the worksheets
Give students time to revise the mind map about “The Dogma Central of Molecular
Biology, and do the exercises.
Check the answers in plenary.
Rosa Macaya
IES Pobla de Segur
17
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.3. Making live possible...from DNA to Proteins
Activity 3.3.
Power Point/Sheet to explain about Scientific Method.
Try to ENGAGE students’ interest though some interactive tasks and make sure
that they understand what they are doing giving and asking for examples.
In plenary explain and then write all the steps of the Scientific Method used to
find out a possible cause of haemophilia.
Teacher should help students with the sentences used to hypothesize and predict.
Rosa Macaya
IES Pobla de Segur
18
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.3. Making live possible...from DNA to Proteins
Review of Molecular Genetics
Activity 1.3.1
Look at the following picture…
“The Central Dogma of Molecular Biology: From DNA to RNA to Protein,,
Rosa Macaya
IES Pobla de Segur
19
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.3. Making live possible...from DNA to Proteins
KEY
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’
3’ .. a t g a t t g c a a a c a t g t t t g g c c t t t a a .. 5’
then write the mRNA
mRNA
3’ .. a u g a u u g c a a a c a u g u u u g g c c u u u a a .. 5’
Look at the pictures below and write the correct name in each label
Aminoacid, tRNA, Ribosome, mRNA
Rosa Macaya
IES Pobla de Segur
20
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
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
Met-Ile-Ala-Asn-Met-Phe-Ala-Leu- STOP
You have made a protein!!!!
Rosa Macaya
IES Pobla de Segur
21
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.3. Making live possible...from DNA to Proteins
KEY
Activity 1.3.2
Mutations
What WILL happen IF....
.........we change a pair nucleotides from the DNA strand….
t ac 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
.
a tg a t t g c a a a c a t g t t t g g c c t t t a c g u
State a hypothesis telling what could happen if you write two “aa” instead
the two tt. You can start the hypothesis…
“If I write aa, in the place of tt then the mRNA will be aa and then
the mRNA would be changed and then the protein would be different.
Now think a “way”, to prove your hypothesis
(Students have to repeat all the process, duplication, transcription and
translation)
mRNA: aug auu gca uuc aug uuu gcc cuu uaa
Protein: Met-Ile-Ala-Phe-Met-Phe-Ala-Leu-STOP
Write down the conclusion.
If nucleotides’ sequence changes in the DNA strand then this change will
carry on during the transcription and the translation. The resultant protein
will be a different one.
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!
Rosa Macaya
IES Pobla de Segur
22
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.3. Making live possible...from DNA to Proteins
(Students have to repeat all the process, duplication, transcription and
translation)
It is an open answer (each student will choose the “mutation”)
Rosa Macaya
IES Pobla de Segur
23
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.3. Making live possible...from DNA to Proteins
KEY
Activity 1.3.2.
Let’s
Scientific Method
and to relate Haemophilia (lack of an appropriate
protein) and inheritance (DNA).
Let’s do 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.) Why doesn’t haemophiliacs’ clotting process happen as it should?
2. Hypothesis – (What do you think you are going to find out?
If the gene of the blood clotting protein is affected by a mutation, the
transcription will carry on the error and mRNA will translate a new protein
unable to do this function
3. Materials and procedure (List the materials you will use in the experiment.)
(In this case it is a theoretical exercise)
The students will have to write a “normal DNA sequence” and do all the
process: duplication, transcription and translation.
Below the same sequence but marking the mutation (some nucleotide changed
or deleted). Again, do all the process: duplication, transcription and
translation.
4. Results – What did you observe when you performed the experiment?
There are two different proteins, the “normal one” from the “normal” DNA
strand and the new one from the “mutated” DNA.
5. Conclusion – From what you observed, how would you answer your original
question? Haemophilia involves a mutation in the protein blood clotting factor DNA
(gene) and this mutation does not let the process of blood clotting happen.
Rosa Macaya
IES Pobla de Segur
24
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.4. Once upon a time playing with pea plants
INTRODUCTION AND RATIONALE
The aim is to end the unit and at the same time to introduce to Mendelian Genetics
through a text about Mendel. From this text students will gain information about
Mendel’s life. This text will also be linked to the start of the next unit. One of the
aims of this lesson is to place Mendel in his time and in the History of Biology.
Warm-up activity
Supplementary Material “Blending Theory”
Explain the “beliefs” about how traits were supposed to pass to the offspring
before Mendel’s findings (Blending Theory) (paper in supplementary material) Make
it clear that Mendel did not know anything about Molecular Genetics.
Write or display the following questions for students to discuss:
• “Why do you think Mendel is known as the Father or genetics?” (Because he
discovered the basic underlying principles of heredity)
• “Do you think that using mathematics to work out the data was usual in
Mendel’s time? (No, he was the first one to made use to this scientific
language)
• What do you think Mendel carried out his breeding experiments with pea
plants? (Because he could observe inheritance patterns in up two generations
a year)
• Think and compare how scientific findings are communicate and published
today and in Mendel’s time. (Here can be told that today the language of
Rosa Macaya
IES Pobla de Segur
25
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.4. Once upon a time playing with pea plants
science is English and that should help the communication. Remember Mendel
published his work in German. Relate this fact with other cases, like
Wegener…)
Rosa Macaya
IES Pobla de Segur
26
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.4. Once upon a time playing with pea plants
Lesson Length: 2 hours
Resource: Student Worksheet: text, table.
Activity 1.4.1. Comprehension text test. Dictionary
• Give out Worksheet 1.4.
• Divide the class into 3 sections (A, B, C).
• Students in Section A receive text A, those in Section B receive text B and
those in section C receive text C.
• Make Section B a group of stronger students.
• Students read their section and fill in the relevant information on their
worksheet.
• Students discuss their answers within their groups.
• Be available to help with vocabulary.
• Students make groups of 3 (one A, one B, one C) and orally exchange
information to fill in the whole chart.
• Check the answers in plenary.
Activity 1.4.2.
• Students are given worksheet 1.4.
• Students work individually to answer the questions referring to their own
texts.
• Students discuss in groups of three to get answers to all of the questions.
• Feedback in plenary.
Discussion:
Go back to the questions in the warm-up and ask students to add their idea
Rosa Macaya
IES Pobla de Segur
27
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.4. Once upon a time playing with pea plants
KEY
Activity 1.4.1
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?
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?
How many basis laws of heredity did he
uncover?
Did he become famous in his life?
Why (not)?
When did he die?
What happened in 1900?
Rosa Macaya
22 July 1822
Farmer
Gardener
Because of financial problems
In the monastery of Brunn
Studied Zoology, Botany, Chemistry and
Physics
Pea plants
They produced tall and short offspring
They only produced short offspring
Tall plants
Over 30,000
More than 8
The law of segregation
The law of independent assortment
six
No
Statistics were unusual at that time
and he was not well known enough
6 January 1884
IES Pobla de Segur
28
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 1
Lesson 1.4. Once upon a time playing with pea plants
KEY.
Activity 1.4.2 Testing the text
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
Rosa Macaya
IES Pobla de Segur
29
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.1. Diving into the pool of genetic terminology
INTRODUCTION AND RATIONALE
The aim of this lesson is to focus on the main concepts of Mendelian Genetics,
using a ppt presentation, during which students will be invited to participate,
answering questions that the teacher will ask, i.e. giving examples.
Prior to this, the hot-seat activity (2.1.1) links the biographies used in lesson 1 to
the teacher’s explanations on Mendelian Genetics.
Lesson Length: 2 hours
Resources: Student
Worksheets 2.1.2 & Student Vocab Pronunciation
Sheet & Word cards (SM)
Activity 2.1.1. Hot Seat
An “able” student sits and adopts the role of Mendel and answer questions asked
by the rest of students (he/she can have a copy of Mendel’s biography)
Students will already have the questions from the last homework from Lesson 1.4.
Activity 2.1.2. Genetic World Words
Through this activity students consolidate the genetic terminology needed.
The activity is divided into four sub-activities, going from easy to more difficult.
This activity is a mixture of writing, oral and listening skills.
A Vocabulary-phonetics transcription sheet (Supplementary Material) should be
given so that students write down (again) the words and their phonetic
transcription.
a) Word puzzle. Students work on their own. After 5 minutes give them the
key.
b) Definition Team Game
Rosa Macaya
IES Pobla de Segur
30
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.1. Diving into the pool of genetic terminology
1. Divide up students into two teams: 1 & 2
2. Give each team a set of 15 words. Give them time to look at them.
3. Teacher reads out the definition and gives students time to find the
matching word.
4. Students shout out the answer when they think they know.
5. Each correct answer: 1 point.
c) Genetic terminology crossword. Students work on their own. After 5 minutes
give them the key.
d) Filling in the gaps: students work on their own and then check their answers
in pairs before a plenary checking plenary. Each student reads out an answer.
Teacher says if it is correct or not.
Rosa Macaya
IES Pobla de Segur
31
INTRODUCTION TO GENETICS
From Proteins to Mendel
Unit 2
Teaching Notes
Lesson 2.1. Diving into the pool of genetic terminology
Activity 2.1.2.
a) Warming up!
KEY
Find the 15 words hidden in the puzzle.
R
D
O
U
W
W
V
O
S
G
E
T
O
I
U
H
K
U
G
J
W
J
R
U
M
E
L
I
K
G
G
N
I
R
P
S
F
F
O
G
L
N
E
H
X
E
V
Q
K
K
H
Z
S
G
S
D
S
E
H
I
S
T
Q
Q
T
J
O
E
Y
I
I
E
H
H
N
G
F
E
R
G
M
J
E
Z
S
K
S
R
M
I
E
P
A
M
O
F
P
M
O
O
I
D
E
B
C
Y
I
T
R
A
P
A
I
M
T
J
K
C
W
S
T
J
H
P
N
G
E
W
O
I
W
A
E
E
P
N
C
D
N
H
M
G
Q
H
M
C
F
S
L
E
H
E
T
E
R
O
Z
Y
G
O
U
S
S
T
R
W
I
D
O
M
I
N
A
N
T
T
Z
I
N
M
K
W
B
Q
K
Z
A
V
I
J
R
E
V
I
V
J
L
K
H
G
Z
L
I
D
I
N
Z
E
X
E
P
U
R
E
T
Q
F
E
D
I
R
B
Y
H
L
CHROMOSOME DOMINANT EGG GAMETE
GENE
HETEROZYGOUS
HOMOZYGOUS
HYBRID
MEIOSIS
MITOSIS OFFSPRING PURE RECESSIVE
SPERM TRAIT
Rosa Macaya
IES Pobla de Segur
32
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.1. Diving into the pool of genetic terminology
b) Definition Team Game
KEY
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
Offspring that are the result of mating between two genetically
different kinds of parents (opposite of purebred)
The study of gene structure and action and the patterns of inheritance
of traits from parent to offspring. This is the branch of science that
deals with the inheritance of biological characteristics.
A XIX century central European monk scientist who published his ideas
about genetics in 1866 but largely went unrecognized until 1900, which
was long after his death. He acquired his understanding of genetics
mostly through pea plant breeding experiments.
A theory that inherited traits blend from generation to generation.
Most of the leading scientists in the XIX century accepted it. However,
Gregor Mendel proved that it was not correct.
Offspring that are the result of mating between genetically similar
kinds of parents (the opposite to hybrid)
Units of inheritance usually occurring at specific locations or loci, on a
chromosome. These units are responsible for hereditary
characteristics in plants or animals.
Alternate forms of the same gene. Because they are different, their
action may result in different expressions of a trait.
The genetic makeup of an individual for a trait or for all of his/her
inherited traits ( no observable or detectable characteristics)
A genotype consisting of two identical alleles of a gene for a particular
trait.
A genotype consisting of two different alleles of a gene for a particular
trait.
The observable or detectable characteristics of an individual organism.
The detectable expression of a genotype.
The general term for an allele that is masked in the phenotype by the
presence of another allele (opposite to dominant allele)
The general term for an allele that masks the presence of another in
the phenotype.
Gregor Mendel ‘s principle of genetic of inheritance stating that, for
any particular trait, the pair of genes of each parent separate (during
meiosis or formation of sex cells) and only one gene from each parent
passes on to an offspring.
Gregor Mendel’s principle of genetic inheritance stating that that
different pair of genes are passed to offspring independently so that
new combination of genes, present in neither parent, are possible. In
other words, the distribution of one pair of alleles does not influence
Rosa Macaya
Hybrid
Genetics
Gregor Mendel
Blending
theory
Purebred
Genes
Alleles
Genotype
Homozygous
genotype
Heterozygous
genotype
Phenotype
Recessive
allele
Dominant allele
Principle of
segregation
Principle of
independent
assortment
IES Pobla de Segur
33
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.1. Diving into the pool of genetic terminology
the distribution of another pair (the genes controlling different traits
are inherited independently or one another.
c)
Genetic Terminology Crossword
KEY
Across
1. Opposite of recessive: DOMINANT
4. Section of DNA: GENE
5. Rewriting DNA's message: TRANSCRIPTING
7. The first cell: ZIGOT
9. Humans have 23 pairs: CHROMOSOMES
Down
2. Different form of a gene: ALLELES
3. Opposite to pure-breeding: HYBRID
4. Combination of alleles: GENOTYPE
6. Proteins Factory: RIBOSOMES
8. Appearance of an organism's trait: PHENOTYPE
10 of 10 words were placed into the puzzle.
Rosa Macaya
Created by Puzzlemaker at DiscoveryEducation.com
IES Pobla de Segur
34
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.1. Diving into the pool of genetic terminology
And to end……..
d) Fill in the gaps: choose the correct word
KEY
1.
Gregor Mendel, the "father of genetics". (Mendel/Darwin)
2. The first hybrid/heterozygous generation is the offspring of a cross
between parents that are pure for a given trait. (Hybrid/Herozygous/
filial)
3. The principle of dominances and recessiviness. (blending/dominances)
4. The outward expression or appearance:
Phenotype (phenotype/genotype)
5. Cross that involves parents that differ in TWO traits.
Dihybrid Cross (dihybrid cross/ Monohybrid cross)
6. The study of heredity: Genetics (heredity/genetics)
7. An alternate form of a gene: Allele (allele/factor)
8. The Principle of Independent Assortment (dependent/independent)
9. Having non identical alleles (not pure; ex. Aa):
Heterozygous (heterozygous/homozygous)
10. Having identical alleles (pure, ex. AA):
Homozygous (heterozygous/homozygous)
11. Square used to determine probability and results of cross:
Punnett (Punnett/Mendel)
12. The allele that is masked or covered up by the dominant allele: recessive
(recessive/dominant)
13. The genetic make-up or an organism (Tt):
Dominant (recessive/dominant)
14. A cross that involves ONE pair of contrasting traits:
Test cross (test cross/ dihybrid cross)
Rosa Macaya
IES Pobla de Segur
35
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.1. Diving into the pool of genetic terminology
15. The plants Mendel did his studies on: Pea Plants (pea plants/peas plants)
16. The likelihood that an event will happen: Probability (probability/chance)
17. When neither allele is dominant (they are both expressed) Codominant
(codominant/recessiviness)
18. Principle of Segregation states that alleles separate when gametes are
formed. (segregation/separation)
Rosa Macaya
IES Pobla de Segur
36
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
INTRODUCTION AND RATIONALE
Through different kinds of exercises students study and apply genetics concepts
(Mendel’s Laws) they already know from lesson 1. The complexity of the problems
grows throughout the lesson, from easy (simple) to more complex exercises (two
traits). Students have to translate the statement to the mendelian nomenclature
following the steps given. At the end of the lesson, students should be able to
solve genetics problems. Also, they have to practise building Punnett squares.
As checking will be done orally, language “of” to help students to explain the
results will be given as scaffolding. (Supplementary material: results sentences)
Lesson Length: 2 hours
Resources: Student Worksheet with the exercises & How to solve
genetics problems (SM) & Results sentences
Procedure: Teacher gives out Worksheet 2.2. with the problems and gives
students time to solve the problems individually. Teacher provides help if
necessary.
The exercises will be checked orally later in plenary.
Rosa Macaya
IES Pobla de Segur
37
INTRODUCTION TO GENETICS
From Proteins to Mendel
Unit 2
Teaching Notes
Lesson 2.2. Swimming with Mendel’s laws
Activity 2.2.1. Simple Genetics Practice Exercises
KEY
1. For each genotype, indicate whether it is heterozygous (HE) or homozygous
(HO)
AA HO
Bb HE
Cc HE_
Dd HE
Ee HE
ff HO
GG HO
HH HO
Ii HE
Jj HE
kk HO
Ll HE
Mm HE
nn HO
OO HO
Pp HO
2. For each of the genotypes below, determine the phenotype.
Purple flowers are dominant to white
flowers
Brown eyes are dominant to blue eyes
PP ___PURPLE___
Pp ___PURPLE___
pp ___WHITE___
BB ___BROWN___
Bb ___BROWN___
bb ___BLUE___
Round seeds are dominant to wrinkled
Short tails are recessive (long tails
dominant)
RR ___ROUND___
Rr ___ROUND___
rr ___WRINKLED___
TT ___LONG TAILS___
Tt ___LONG TAILS___
tt ___SHORT TAILS___
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.
___SS___ straight
___Ss___ straight
___ss___ curly
___PP___ pointed
___Pp___ pointed
___pp___ round
Rosa Macaya
IES Pobla de Segur
38
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
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)
What percentage of the
offspring will be round?
50%
Rr
Rr
rr
rr
Rr x Rr
RR
rR
Rr
rr
What percentage of the
offspring will be round?
75%
RR x Rr
RR
RR
Rr
Rr
What percentage of the
offspring will be round?
100 %
Rr x rr
Practice with Crosses.
5. A TT (tall) plant is crossed with a tt (short plant).What percentage of the
offspring will be tall?
Cross: TT x tt: 100% will be tall
6. A Tt plant is crossed with a Tt plant. What percentage of the offspring
will be short?
Cross: Tt x Tt: 25% 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)?
Cross: Rr x RR: 50% will be homozygous
Rosa Macaya
IES Pobla de Segur
39
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
8. A homozygous round seeded plant is crossed with a homozygous wrinkled
seeded plant. What are the genotypes of the parents?
The parents’ genotype is: RR x rr
What percentage of the offspring will also be homozygous?
None homozygous offspring 0%
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?
PP: purple
pp: white
pp x pp (white x white)
100 % will be white
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?
Pp: (purple)
Pp x pp = 50 % of the offspring will be purple
pp: (white)
___________
11. Two plants, both heterozygous for the gene that controls flower colour are
crossed. What percentage of their offspring will have purple flowers?
Cross: Pp x Pp : 75 % will have purple flowers
What percentage will have white flowers? 25 % 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?
S = short hair
A heterozygous guinea pig will have Ss genotype
S = long hair
What genotype would a pure breeding short haired guinea pig have?
SS
What genotype would a long haired guinea pig have? S
13. Show the cross for a pure breeding short haired guinea pig and a long
haired guinea pig
Rosa Macaya
IES Pobla de Segur
40
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
S
S
s
sS
sS
s
sS
sS
Cross:
P:
F1:
SS x ss
Ss
What percentage of the offspring will have short hair? 0 %
14. Show the cross for two heterozygous guinea pigs.
S
s
S
SS
Ss
s
sS
ss
Cross:
P:
F1:
Ss x Ss
SS Ss ss
What percentage of the offspring will have short hair? 75 %
What percentage of the offspring will have long hair? 25%
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? _Ss_ x _Ss_ Show the cross to prove it!
Rosa Macaya
IES Pobla de Segur
41
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
S
s
Cross:
S
SS
Ss
s
sS
ss
P: Ss x Ss
Gametes S s S s
F1: SS Ss sS ss
Rosa Macaya
IES Pobla de Segur
42
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
Activity 2.2.2. Two traits genetics crosses
KEY
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
Gg = grey hair
Bb = black eyes
gg = white hair
bb = red eyes
These letters represent the genotypes
of the rabbits:
1. What are the phenotypes (descriptions) of rabbits that have the following
genotypes?
Ggbb _Grey hair and red eyes_ ggBB _White hair and black eyes_
ggbb _White hair and red eyes_ GgBb _Grey hair and black eyes_
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
gGBb
gGBb
gGbb
gGbb
Gb
gGBb
gGBb
gGbb
gGbb
Gb
gGBb
gGBb
gGbb
gGbb
Gb
gGBb
gGBb
gGbb
gGbb
How many out of 16 have grey fur and black eyes? 8/16
Rosa Macaya
IES Pobla de Segur
43
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.2. Swimming with Mendel’s laws
How many out of 16 have grey fur and red eyes? 8/16
How many out of 16 have white fur and black eyes? 0
How many out of 16 have white fur and red eyes? 0
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.
GgBb: GB Gb gB gb (four different gametes)
4. A female rabbit has the genotype ggBb. Determine the gametes (eggs)
produced by this rabbit.
ggBb:
gB gb gB gb (two different gametes)
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
GgBB
GgbB
ggBB
ggbB
gb
GgBb
Ggbb
ggBb
ggbb
GgBB: Grey fur and black eyes: 3/8
Ggbb: Grey fur and red eyes: 1/8
ggBB: White fur and black eyes: 3/8
ggbb: White fur and red eyes: 1/8
Rosa Macaya
IES Pobla de Segur
44
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.3. Swinging with Mendel’s laws exceptions
INTRODUCTION AND RATIONALE
In this lesson students will practise the non-mendelian patterns of inheritance
such
as
codominance
and
intermediate
expression,
multiple
alleles,
sex
determination and sex-linked traits.
Although the theoretical background has been already explain through a ppt
presentation, students can read a short summary of the content before the
exercises. Through these problems and questions students will consolidate the way
to solve and deepen their understanding of content and English knowledge.
The teacher should tell the students that these points are necessary to end the
project and to have background in order to write the report answering Mrs
Drinkwater’s question.
As checking will be done orally, language “of” to help students to explain the
results will be given as scaffolding. (Supplementary material: results sentences)
Lesson Length: 3 hours
Resources: Student Worksheet with the exercises & How to solve genetics
problems (SM) & Results sentences (already given in lesson 2)
Procedure: Teacher gives out Worksheet 2.3. with the problems and gives
students time to solve the problems individually. Refer students to the text
above each part to give them extra support to complete the tasks. Teacher
provides help if necessary.
The exercises will be checked orally later in plenary.
Rosa Macaya
IES Pobla de Segur
45
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.3. Swinging with Mendel’s laws exceptions
Activity 2.3.1
Codominance, 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.
KEY
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.
Blue BB White WW Blue-tipped: BW
b) Flowers can be white, pink, or red.
Red: CRCR White: CWCW Pink: CRCW
c) A
can have curly hair, spiked hair, or a mix of both curly and spiked.
(H=hair)
Curly Hair HCHC
d) A
Spiked Hair HSHS Mix (curly&spiked) Hair HCHS
can be tall, medium, or short. (S=size)
Tall: STST
Medium: STSS
Short: SSSS
Rosa Macaya
IES Pobla de Segur
46
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.3. Swinging with Mendel’s laws exceptions
e) A
can be spotted, black, or white. (colour)
Black: CBCB
White: CWCW
Spotted: CBCW
2. Now, can you figure out in the above list, which of the examples represent
codominant traits and which are incomplete.
Codominant: _c,e_
Incompletely Dominant: _a, b, d_
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 than 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.
If Mrs Drinkwater’s mother is o, her genotype is ii and we can state that Mrs.
A
Drinkwater’s genotype is I i. Children’s phenotypes: 0 A B
P: IAi
x ¿?
F1: ii // iIA or IAIA // iIB or IBIB
With this information we can state that the father could be
B B
B
B
B A
(genotype: I I or I i) or AB (genotype I I )
Rosa Macaya
IES Pobla de Segur
47
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
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
X-chromosome. 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.
KEY
a) What will be the sex of a child produced when an egg is fertilized by a
sperm that has a Y chromosome? Male
What type of sperm must fertilize an egg to result in a female child?
A sperm that has an X chromosome
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.
Rosa Macaya
IES Pobla de Segur
48
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.3. Swinging with Mendel’s laws exceptions
X
Y
X
XX
XY
X
XX
XY
c) Based on this Punnett Square, what percent of children would you expect to
be male?
MALE: 50%
FEMALE: 50%
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
KEY
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)
Rosa Macaya
IES Pobla de Segur
49
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.3. Swinging with Mendel’s laws exceptions
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.
XhY
P:
Gametes: X
F1 :
h
x
XhXH
Xh XH
Y
XhXh XHXh XhY
Xh
Y
Xh
XhXh
XhY
XH
XHXh
XHY
XH Y
What is the probability that their children will have the disease?
50% probability of having a haemophilic girl and the same probability if it is
a boy
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?
Rosa Macaya
IES Pobla de Segur
50
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.3. Swinging with Mendel’s laws exceptions
H
Woman genotype: X X
h
H
Man genotype: X Y
Phenotype: normal
XHXh x
P:
F1 :
Phenotype: normal
XHXH XHY
XH Y
XhXH XhY
Probability of having a haemophilic SON 50% from the male children.
No GIRLS suffered from haemophilia, so 0% for female children.
A woman who has haemophilia marries a normal man. How many of their
children will have haemophilia, and what is their sex?
h
Woman genotype: X X
H
Man genotype: X Y
P:
F1 :
h
Phenotype: haemophilic
Phenotype: normal
XhXh x XHY
XhXH XhY XhXH XhY
All their male children will be haemophilic.
Rosa Macaya
IES Pobla de Segur
51
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.4. Let’s have children!...and something else
INTRODUCTION AND RATIONALE
The aim of the last part of the project is for students to apply most of the
knowledge they have gained during the project.
It includes a game in which
students simulate the “production” of children with certain traits using
chromosomes with samples of all kinds of inheritance patterns done in prior
lessons.
Students then revisit the question posed by Mrs Drinkwater at the beginning of
the project. Again, by using all their knowledge, the students write a report to
answer her question.
Students are asked to show how they are able to make use of the content they
have acquired, applying different skills.
As a final activity it is also an assessment activity where the whole content has to
be used.
To finish the project, there is an oral discussion on science & technology & society.
The overall aim of these activities is to consolidate all the content and the use of
the target language in a very integrated task and close the project as a loop.
Lesson Length: 3-4 hours
Resources:
Student Worksheets 2.4.1
Student Vocab Pronunciation Sheet
Set of 4X2 chromosomes for each student
Sheet “How to write a genetic Report” and the sheet “How to create a
pedigree chart”
Previous Students’ Worksheet to review.
Access to the internet or books.
PP Presentation (Let’s have children, in SM)
Rosa Macaya
IES Pobla de Segur
52
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
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?
Procedure
Students work in pairs.
They follow the instructions on the student’s worksheet (say which
number worksheet it is)
Analyse the results in plenary: students read out the results and
explain the conclusions they have reached.
Pick out some of the student’s opinions about their results Help them to
summarize the conclusions and focus them on the main goals, for
instance the role of chance in heredity, the importance of sexual
reproduction, the independence of the events …
Activity 2.4.2. Genetic Report
Procedure
Students work in groups of 3-4 students.
Teacher gives each group a sheet with the instructions saying what the
report should include (Supplementary Material “How to write the
Genetic Report).
PART I: Students will probably need to re read the story about the
Drinkwater family. They can look at the pedigree done in lesson 1.2. and
from that and with the help of the sheet “how to create a pedigree
chart” they can create the new one. This pedigree has to show:
Rosa Macaya
IES Pobla de Segur
53
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.4. Let’s have children!...and something else
All family members mentioned
All affected individuals
All known carriers and suspected carriers.
PART II: Students use the questions on the sheet to guide them
PART III: In order to complete this section the student can revise the
poster they did in lesson 1.2.
Explain how Haemophilia is inherited and what a sex-linked trait is
Explain the difference between haemophilia A and haemophilia B*
Explain the signs and symptoms of haemophilia
Explain the treatment options for haemophilia, including future
treatments being researched (hypothetical) or genetic screening…
Each group writes a genetic report for the Drinkwater family
When the report is finished students share in plenary their report.
Teacher collects in the reports to check them and give feedback.
(To continue this genetic cabinet feedback a further discussion about if sex
selection should or should not be recommended.
Students will/should be able to make decisions on sex selection cases, rationalize
their decision/choices on sex selection and understand the ethical/moral
implications of their decisions.)
KEY
..
Part II: Paragraph about the Drinkwater Family's Haemophilia
Explain who has the disorder and who does not
Mrs. Drinkwater’s dead brother, Paul Pennymann and her youngest son, Tom
Drinkwater
Explain who in the family is a carrier and who could be a carrier
Rosa Macaya
IES Pobla de Segur
54
INTRODUCTION TO GENETICS
From Proteins to Mendel
Teaching Notes
Unit 2
Lesson 2.4. Let’s have children!...and something else
Mother Pennymann, Mrs Drinkwater. Mrs. Drinkwater’s daughter could be a
carrier.
Explain the risk of the next child having the disorder or being a carrier
of the disorder (a Punnett square may be used to help explain this
section)
If the next child is a girl, she has a 50% probability of being a carrier. If
boy, 50 % probability of being a sufferer
What chromosome is the mutation is located in? (chromosome X)
What protein is affected by the mutation? (Blood clotting protein)
Activity 2.4.3 Role Play game: Let’s discuss!
Procedure:
Divide the class into two groups.
Give out worksheet no. XXX
Designate one group as for and one group as against.
Give the groups time to think of ideas and note them down.
Give students the sentence banks to help with language (XXX)
Conduct a debate, with one student from each group acting as
secretary.
Rosa Macaya
IES Pobla de Segur
55