MUTATION-SCIENCE 8 POWERPOINT PRESENT

MUTATION

1. M U T A T I O N S

2. MUTATIONS Are changes or alterations in DNA sequences. They usually manifest on our physical characteristics.

3. Adverse effects of Mutations: Genetic disorders – caused by mutations in one or more genes. (e.g. cystic fibrosis) Diseases like cancer – cancer cell are cells that grow out of control, forming tumors that destroy healthy cells around the tumor. Cancer cells can also cause an excess of abnormal cells in the blood. (e.g. leukemia)

4. TWO TYPES OF MUTATIONS BASED ON CAUSES: Hereditary / Germline mutations these are inherited from parents. They are present in almost all the cells (including the germ cells or the reproductive cells) in bodies because they are inherited. Acquired / Somatic mutations these occur usually because of lifestyle or environmental factors like exposure to chemicals or diseases.

5. TWO TYPES OF MUTATIONS Gene Mutation – is a permanent change in the DNA sequence that makes up a gene. Chromosomal Mutation – occurs at the chromosome level resulting in gene deletion, duplication or rearrangement that may occur during the cell cycle and meiosis. It maybe caused by parts of chromosomes breaking off or rejoining incorrectly.

6. Different Types of Chromosomal Mutations:

7. 1.DUPLICATION occur when part of a chromosome is abnormally copied(duplicated ).

8. 2.INVERSION occurs when a chromosome breaks in two places; the resulting piece of DNA is reversed and re-inserted into the chromosome.  

9. 3.DELETION occur when a chromosome breaks and some genetic material is lost.

10. 4.INSERTION Occurs when extra pairs are inserted into a new place.

11. 5.TRANSLOCATION occurs when a piece of one chromosome breaks off and attaches to another chromosome. 

12. NORMAL HUMAN KARYOTYPE

13. COMMON EFFECTS OF MUTATIONS Cri – du chat Down Syndrome Edward’s Syndrome Kinefelter’s Syndrome Turner’s Syndrome Albinism Pallister Killian Syndrome Jacobsen Syndrome

14. EFFECTS OF MUTATION

15. CRI – DU – CHAT SYNDROME is caused by the deletion of part of the short arm of chromosome 5. Symptoms vary greatly, but common characteristics include a high-pitched cat-like cry, slow growth, and microcephaly, small head size.

16. DOWN SYNDROME is usually caused by an extra copy of chromosome 21(trisomy 21). Characteristics include decreased muscle tone, stockier build, asymmetrical skull, slanting eyes and mild to moderate mental retardation.

17. EDWARD’S SYNDROME is the second most common trisomy after Down’s syndrome, is a trisomy of chromosome 18. Symptoms include mental and motor retardation and numerous congenital anomalies causing serious health problems.

18. JACOBSEN SYNDROME is also called terminal 11q deletion disorder. This is a very rare disorder. Those affected have normal intelligence or mild mental retardation, with poor or excessive language skills.

19. Pallister Killian Syndrome

20. ALBINISM D eletion mutation can lead to albinism. It is an autosomal recessive disorder in which the formation of melanin is reduced or absent in skin, hair, and eyes due to the lack of activity of tyrosinase . This is caused by the deletion of the tyrosinase gene.

21. KLINEFELTER’S SYNDROME (XXY) and TURNER’S SYNDROME

22. CYSTIC FIBROSIS Another is the Cystic Fibrosis (CF). It is a recessive inherited disorder. Although there are many different mutations that can cause cystic fibrosis, deletion mutation is the most common cause. It affects the cystic fibrosis transmembrane conductance regulator (CFTR) gene that leads to the deletion of the amino acid phenylalanine. This causes an incorrect protein .

23. GENETIC ENGINEERING A modern biotechnology that produce tran s genic or GM crops. Recombinant DNA – DNA from two different specie s are joined together. T ransgenic are able to manufacture genetic products foreign to them using recombinant DNA. Genetic Engineering has been applied to bacteria, plants and animals.

24. QUIZ