Genetics Unit – Lesson 8: Genetic Disorders & Mutation
Course: Monarch Park
Grade IB Biology (SBI-4IB)
Teacher: Ms. Founk
Email: monarchpark.sbi4ib@gmail.com

Human maladies
STDs
Cholera
Stroke
Measles
Chicken pox
Tuberculosis
Sickle cell anemia
Crohn’s
Malaria
Lou Gehrig’s Disease/ALS
Lung cancer
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants

Do you make more errors than a cell?
Errors during meiosis: Non-disjunction
Meiosis is a process that uses cellular division to produce the sex cells or gametes that are used for reproduction. During meiosis, the cell identifies chromosome pairs and sorts them to opposite sides of the cell. Sometimes, errors occur during this sorting process resulting in extra or missing chromosomes.
INSTRUCTIONS
• Cut out chromosomes pairs
• Mix the shapes in a pile on your desk. Imagine that this represents the nucleus of a cell
• When instructed, sort the 23 chromosome pairs as fast as you can so that 1 copy of each chromosome is on either side of your desk.
• You will have 1 minute to sort.
• After 1 min, record the number of pairs you were able to successfully sort
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants

Karyotyping
Detecting chromosome abnormalities
Chromosomes are sorted according to several characteristics:
• Chromosome length
• Chromosome structure
• Banding pattern
• Position of centromere
Karyotypes are used to assess the sex of a person
The X chromosome is much larger than the Y chromosome
• XX = female
• XY = male
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants

Detecting chromosome abnormalities
Karyotyping
Varying numbers of sex chromosomes lead to a variety of different disorders
TURNER SYNDROME (XO = female) TRIPLE X (XXX = female)
Watch this talk: http://www.ted.com/talks/lang/en/alice
_dreger_is_anatomy_destiny.html
KLINEFELTER SYNDROME (XXY = male)
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants

Detecting chromosome abnormalities
Karyotyping
Varying numbers of autosomes lead to a variety of different disorders
DOWN SYNDROME (Trisomy 21) Look up
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
Look up

Do you make more errors than a cell?
Errors during DNA replication: Point mutations
DNA replication occurs before mitosis and meiosis so that a new copy of DNA is created.
The cell is very good at copying the 3 billion base pairs of DNA present in every human cell, but sometimes it makes mistakes.
Sequence:
Copy of Sequence:
ATCCGACGTTTGCGATCGATCGATGGGGTCGATAAAAGCT
____________________________________________
Number of mistakes: _______________________
Complementary Sequence: ____________________________________________
Number of mistakes: _______________________
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants

Point mutations are single nucleotide changes in the DNA
Point mutations can have varying effects within the cell e.g. Transcribe and translate the following sense strand: TTA TAT CTC
GTA UUA UAU CUC GUA
Leu Met Leu Val
TTA TAT A TC GTA
UUA UAU A UC GUA
Leu Met Ile Val
TTA TAT CT T GTA
UUA UAU CU U GUA
Leu Met Leu Val
TTA TA A CTC GTA
UUA UA A CUC GUA
Leu Stop
TTA T TA TCT CGT A
UUA U UA UCU CGU A
Leu Leu Ser Ala
Missense mutation Silent mutation Nonsense mutation Frameshift mutation
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants

A Case Study: Sickle Cell Anemia
sense sense
Glutamic acid
CCU GAG GAG
Pro Glu Glu
Valine
CCU G U G GAG
Pro Val Glu
Normal blood cell
Sickle cell anemia
Changing a single nucleotide changes the mRNA sequence which changes the codon which changes the amino acid. Glutamic acid and valine have very different chemical and physical properties which affects the ability of the hemoglobin to form proper quaternary structure resulting in sickle looking cells that have decreased ability to carry oxygen in the blood.
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants

Repair pathways within the cell
SIDE NOTE: The cell has proteins that work to repair DNA
BRCA1 – gene linked to breast cancer
-Repairs cell from double strand breaks
Repair proteins can be identified using DNA damage foci
BLAST tool from NCBI can be used to align sequences and detect sequence differences
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants

Genetics Unit – Lesson 8: Genetic Disorders & Mutation
Course: Monarch Park
Grade IB Biology (SBI-4IB)
Teacher: Ms. Founk
Email: monarchpark.sbi4ib@gmail.com

Do you make more errors than a cell?
Errors during meiosis: Non-disjunction
Meiosis is a process that uses cellular division to produce the sex cells or gametes that are used for reproduction. During meiosis, the cell identifies chromosome pairs and sorts them to opposite sides of the cell. Sometimes, errors occur during this sorting process resulting in extra or missing chromosomes.
INSTRUCTIONS
• Cut out chromosomes pairs
• Mix the shapes in a pile on your desk. Imagine that this represents the nucleus of a cell
• When instructed, sort the 23 chromosome pairs as fast as you can so that 1 copy of each chromosome is on either side of your desk.
• You will have 1 minute to sort.
• After 1 min, record the number of pairs you were able to successfully sort
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants

Karyotyping
Detecting chromosome abnormalities
Chromosomes are sorted according to several characteristics:
• Chromosome _________
• Chromosome _________
• ________________
• ________________
Karyotypes are used to assess the sex of a person
The X chromosome is much
_______than the Y chromosome
• XX = ____________
• XY = ____________
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants

Detecting chromosome abnormalities
Karyotyping
Varying numbers of ________________ lead to a variety of different disorders
Watch this talk: http://www.ted.com/talks/lang/en/alice
_dreger_is_anatomy_destiny.html
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants

Detecting chromosome abnormalities
Karyotyping
Varying numbers of _____________ lead to a variety of different disorders
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants

Do you make more errors than a cell?
Errors during DNA replication: Point mutations
DNA replication occurs before mitosis and meiosis so that a new copy of DNA is created.
The cell is very good at copying the 3 billion base pairs of DNA present in every human cell, but sometimes it makes mistakes.
Sequence:
Copy of Sequence:
ATCCGACGTTTGCGATCGATCGATGGGGTCGATAAAAGCT
____________________________________________
Number of mistakes: _______________________
Complementary Sequence: ____________________________________________
Number of mistakes: _______________________
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants

Point mutations are single nucleotide changes in the DNA
Point mutations can have varying effects within the cell e.g. Transcribe and translate the following sense strand: TTA TAT CTC
GTA UUA UAU CUC GUA
Leu Met Leu Val
TTA TAT A TC GTA TTA TAT CT T GTA
UUA UAU
Leu Met
A UC GUA
Ile Val
UUA UAU CU U GUA
Leu Met Leu Val
TTA TA A CTC GTA
UUA UA A CUC GUA
Leu Stop
TTA T TA TCT CGT A
UUA U UA UCU CGU A
Leu Leu Ser Ala
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants

A Case Study: Sickle Cell Anemia
sense sense
Glutamic acid Valine
______________ ______________
Changing a single nucleotide changes the mRNA sequence which changes the codon which changes the amino acid. Glutamic acid and valine have very different chemical and physical properties which affects the ability of the hemoglobin to form proper quaternary structure resulting in sickle looking cells that have decreased ability to carry oxygen in the blood.
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants