Download Key Area 2 – Pupil Booklet

Williamwood High School
Biology Department
KA
1.2
Biology National 4
Unit 1 – Cell Biology
Key area 1.2
DNA, genes and chromosomes
Name ______________________________
Unit 1 – Cell Biology
Key area 2 – DNA, genes and chromosomes
Learning Objectives
Learning Outcomes
1:2 DNA, genes and chromosomes.
I can…
1. state that genes are located on chromosomes in the nucleus of every cell.
2. state that a gene is a section of DNA which controls an inherited
characteristic.
3. state that genes are passed on from parents to offspring in the egg and
sperm
4. state that every individual’s DNA is unique except for identical twins.
5. state that DNA carries the instructions to make proteins and this is
termed the genetic code.
6. state that DNA is made up of building blocks made of sugar, phosphate and
the four bases A,T C and G
7. give the opposite bases in a genetic code with the letters A,T C and G
8. explain that by testing a DNA sample, this information can be used to
identify a person’s father, or can be used to link people to a crime scene.
10. state that testing for a particular gene can identify a genetic disorder.
11. discuss examples of inherited characteristics
Page 2
INHERITANCE


Characteristics are passed down from parents to their children.
This is called inheritance.
Activity 1 The Simpsons
Look at the Simpson characters on the card.
Write down the names of 3 people who are related to each other.
___________________ __________________ ___________________
How could someone who has never seen the Simpsons tell who are related?
Name 2 characteristics that you think you have inherited from your parents.
_________________________ ______________________________
Page 3
How are characteristics inherited?



The information to make our characteristics is found in every cell of the
body.
It is found in our chromosomes, which are tightly packed inside the
nucleus of each cell.
We inherit our 46 chromosomes from our parents during fertilisation of
the egg by the sperm.
Chromosomes

The nucleus of all cells contains chromosomes that carry ___________
information.

Chromosomes are made from long coiled molecules called _________

A ____________ is a short region of DNA that carries the code for a
particular characteristic.
Page 4
Genes

Genes are sections of ___________ found on our chromosomes.

Each person inherits a different combination of genes from their
parents. This makes each person unique.
The only people who are not genetically unique are ______________

________________. This is because they have come from the same
_________________
_______________ which split in two. This
means that they have identical DNA.
To do
Explain why non-identical twins are not genetically the same.
DNA profiling

Everyone’s DNA is unique. It is because of this property that we are
able to catch criminals using DNA samples, and determine who is the
father of a child.
Activity 2 Watch the video clip on DNA profiling and answer the questions.
1. How many bases are there in human DNA? _____________
2. What % of human DNA is the same in all humans? _________
3. What % of our DNA is unique to us? ___________
4. In what year was DNA first used to match an individual to a
crime? _________________
5. Hairs from a crime scene can be used in DNA profiling. Name two
other substances from a crime scene that can be used.
_______________________
Page 5
______________________
DNA structure
Your teacher will show you a model of DNA.

DNA is made of ________ strands joined together.

DNA looks like a twisted ladder and is called a _________ _________.
A SHORT LENGTH OF
A DNA MOLECULE
Detailed structure of DNA


DNA is made up of smaller building blocks which are all joined together
in a double row.
These building blocks each contain a sugar, a phosphate and a base.
To do
Label the diagram showing one of these building blocks of DNA.
A building block
of DNA
Page 6


There are four different bases that are found in a DNA molecule.
These are known by their initial letters.

These letters are _______ ______ ______ and ______

The bases in opposite strands of DNA always pair up in the same way.

A always pairs with ______.
G always pairs with ______.

These bases make up the _____________ code.

This means that if the genetic code of one strand is
A T T C G G T A C then the opposite strand will be
T A A G C C A T G.
Activity 3 Crack the code

In the top line of the box below, use the letters A,T G and C to
create a code 15 letters long.

Pass it to your partner to work out the code on the opposite strand.
Activity 4 DNA model

Your teacher will give you a cut-out sheet which you can use to make
a model of a DNA molecule.
Page 7
CHECK TEST 1 – Circle the correct answer.
1. Chromosomes are found in the
A
cytoplasm
B
cell membrane
C
nucleus
D
all of these
2. Chromosomes are made of
A
cells
B
DNA
C
chloroplasts
D
glucose
3. What is a gene?
A
a human egg cell
B
a human sperm cell
C
a micro-organism
D
a length of DNA
4. The genetic code on one strand of DNA is TAACTGGAC. What is the code
on the opposite strand?
A
ATTGACCTG
B
TAACTGGAC
C
GCCAGTTCA
D
CAGGTCAAT
5. DNA is made of building blocks. What three parts are found in these
building blocks?
A sugar, water and base
B phosphate, sugar and base
C base, phosphate and oxygen
D sugar, base and nitrate
Page 8
6. Which of the following describes identical twins?
A
B
C
D
genetically different, coming from one egg and one sperm
genetically different, coming from two eggs and two sperms
genetically identical, coming from one egg and one sperm
genetically identical, coming from two eggs and two sperms
TOTAL __/6
DNA Scientists

Several scientists were involved in discovering the structure of
DNA.
Activity 5
Watch the video clip and answer these questions.
1. What did Watson and Crick use to discover the shape of DNA?
2. What did photograph 51 reveal?
_______________________________________________
3. How is the shape of a DNA molecule described?
_______________________________________________
4. Which 3 scientists received a Nobel Prize in 1953 for their work on
DNA?
__________________ __________________ _______________
5. Why did the fourth scientist not receive a Nobel prize?
______________________________________________________
Page 9
Activity 6
Who am I?
• Your teacher will take you to an ICT room.
• Select a DNA scientist and research their work and life. Choose from
the following list:
Francis Crick
James Watson
Rosalind Franklin
Maurice Wilkins
•
Create a Facebook page for this scientist using the template for Word.
Inherited diseases


Some human conditions and diseases are inherited, and can pass on
from one generation to the next.
Sometimes this is caused when people lack the gene to make a
particular protein.
To do
Complete the table to show the information about these inherited diseases.
Name of condition
Symptoms of condition
Protein missing
Diabetes
Melanin
Page 10
Case studies of inherited diseases
Ethical issues



Your teacher will give each group a card about an inherited disease.
Discuss in your group the ethics questions on the powerpoint slide.
Share your ideas with the class.
Research task


Research your inherited disease on the internet.
Do the task at the bottom of the card.
Page 11
DNA COLOURING
Page 12
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