Genetics Unit – Lesson 8: Genetic Disorders & Mutation
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Genetics Unit – Lesson 8: Genetic Disorders & Mutation
Course: Monarch Park Grade IB Biology (SBI-4IB)
Teacher: Ms. FounkEmail: monarchpark.sbi4ib@gmail.com
Human maladies
Melanoma
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
Heart disease
Cold/Flu
HIV/AIDSKidney stones
Alzheimers
Parkinson’s disease
Huntington’s disease
Lou Gehrig’s Disease/ALS
Autism
Lung cancer
Crohn’s
Tuberculosis
Chicken poxMeasles
Cholera
Scurvy
STDs
Sickle cell anemia
Stroke
Malaria
Down syndrome
Do you make more errors than a cell?
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
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
Detecting chromosome abnormalities
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
Karyotyping
• Chromosome length• Chromosome structure
• Banding pattern• Position of centromere
Chromosomes are sorted according to several characteristics:
The X chromosome is much larger than the Y chromosome
• XX = female• XY = male
Karyotypes are used to assess the sex of a person
Detecting chromosome abnormalities
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
Karyotyping
TRIPLE X (XXX = female)
Varying numbers of sex chromosomes lead to a variety of different disorders
TURNER SYNDROME (XO = female)
KLINEFELTER SYNDROME (XXY = male)
Watch this talk:http://www.ted.com/talks/lang/en/alice_dreger_is_anatomy_destiny.html
Detecting chromosome abnormalities
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
Karyotyping
Look up
Varying numbers of autosomes lead to a variety of different disorders
DOWN SYNDROME (Trisomy 21) Look up
Do you make more errors than a cell?
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
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: ATCCGACGTTTGCGATCGATCGATGGGGTCGATAAAAGCT Copy of Sequence: ____________________________________________ Number of mistakes: _______________________
Complementary Sequence: ____________________________________________ Number of mistakes: _______________________
Point mutations are single nucleotide changes in the DNA
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
Point mutations can have varying effects within the cell
Missense mutation
TTA TAT ATC GTA
Silent mutation
TTA TAT CTT GTA TTA TTA TCT CGT A
Frameshift mutation
TTA TAA CTC GTA
Nonsense mutation
e.g. Transcribe and translate the following sense strand: TTA TAT CTC GTAUUA UAU CUC GUALeu Met Leu Val
UUA UAU AUC GUALeu Met Ile Val
UUA UAU CUU GUALeu Met Leu Val
UUA UAA CUC GUALeu Stop
UUA UUA UCU CGU ALeu Leu Ser Ala
A Case Study: Sickle Cell Anemia
Transcribe and translate a section of the genome that encodes for hemoglobin (Hb)
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
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.
sense
CCU GAG GAG
Pro Glu Glu
CCU GUG GAG
Pro Val Glu
Glutamic acid Valine
sense
Sickle cell anemiaNormal blood cell
Repair pathways within the cell
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
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
Genetics Unit – Lesson 8: Genetic Disorders & Mutation
Course: Monarch Park Grade IB Biology (SBI-4IB)
Teacher: Ms. FounkEmail: monarchpark.sbi4ib@gmail.com
Do you make more errors than a cell?
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
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
Detecting chromosome abnormalities
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
Karyotyping
• Chromosome _________• Chromosome _________
• ________________• ________________
Chromosomes are sorted according to several characteristics:
The X chromosome is much _______than the Y chromosome
• XX = ____________• XY = ____________
Karyotypes are used to assess the sex of a person
Detecting chromosome abnormalities
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
KaryotypingVarying 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
Detecting chromosome abnormalities
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
KaryotypingVarying numbers of _____________ lead to a variety of different disorders
Do you make more errors than a cell?
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
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: ATCCGACGTTTGCGATCGATCGATGGGGTCGATAAAAGCT Copy of Sequence: ____________________________________________ Number of mistakes: _______________________
Complementary Sequence: ____________________________________________ Number of mistakes: _______________________
Point mutations are single nucleotide changes in the DNA
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
Point mutations can have varying effects within the cell
TTA TAT ATC GTA TTA TAT CTT GTA TTA TTA TCT CGT ATTA TAA CTC GTA
e.g. Transcribe and translate the following sense strand: TTA TAT CTC GTAUUA UAU CUC GUALeu Met Leu Val
UUA UAU AUC GUALeu Met Ile Val
UUA UAU CUU GUALeu Met Leu Val
UUA UAA CUC GUALeu Stop
UUA UUA UCU CGU ALeu Leu Ser Ala
A Case Study: Sickle Cell Anemia
Transcribe and translate a section of the genome that encodes for _______________
Monarch Park SBI-4IB – Genetics Unit – Lesson 8: Genetic Disorders & Mutants
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.
sense
Glutamic acid Valine
sense
____________________________
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