The document is a seminar presentation on mutation by Keerti Gupta from St. John's College Agra, covering the definition, history, classifications, and types of mutations. It details the impact of mutations on survival, the distinction between spontaneous and induced mutations, and their applications in crop improvement. Additionally, it describes various gene and chromosomal mutations along with examples, illustrating how mutations can be neutral, harmful, or beneficial.

1. ST. JOHN’S COLLEGE AGRA
DEPARTMENT OF BOTANY
SEMINAR PRESENTATION ON
MUTATION
PRESENTED BY- KEERTI GUPTA
SUBMITTED TO- DR. SAKSHI WALKER
CLASS- MSC(P)
SESSION- 2020-21

3. MUTATION IS THE CHANGE OF NUCLEOTIDE SEQUENCE
OF THE GENOME OF AN ORGANISM
OR CHROMOSOMAL DNA OR OTHER GENETIC ELEMENTS.

4. HISTORY
 SETH WRIGHT RECORDED CASE OF MUTATION FIRST
TIME IN 1791 IN MALE LAMB WITH UNUSUAL SHORT
LEGS.
 HUGO DE VRIES COINED THE TERM MUTATION IN 1900
BY HIS OBSERVATION IN OENOTHERA.
 MORGAN GENETICALLY ANALYSED WHITE EYE MUTANT
OF DROSOPHILA IN 1910.
 H.J. MULLER INDUCED MUTATION IN DROSOPHILA BY
USING X-RAYS IN 1927, HE WAS AWARDED WITH
NOBEL PRIZE IN 1946.

5. CLASSIFICATION OF MUTATION
BASED ON THE SURVIVAL OF AN INDIVIDUAL
1. LETHAL MUTATION- CAUSES DEATH OF ALL INDIVIDUALS
2. SUB LETHAL MUTATION- CAUSES DEATH OF 90%
INDIVIDUALS
3. SUB VITAL MUTATION- KILLS LESS THAN 90% INDIVIDUALS
4. VITAL MUTATION- DON’T AFFECT THE SURVIVAL OF AN
INDIVIDUAL
5.SUPER VITAL MUTATION- ENHANCES THE SURVIVAL OF
INDIVIDUAL

6. BASED ON CAUSES OF MUTATION
1. SPONTANEOUS MUTATION- OCCUR NATURALLY BY
CHANGES IN DNA SEQUENCE DURING REPLICATION.
E.g.- METHYLATION FOLLOWED BY DEAMINATION
OF CYTOSINE.
2. INDUCED MUTATION- CAUSED BY CHEMICALS OR
ENVIRONMENAL FACTORS CALLED MUTAGENS.
E.g.- UV LIGHT, X-RAYS, GAMMA RAYS ETC.
USE OF INDUCED MUTATION FOR CROP IMPROVEMENT
PROGRAM IS CALLED MUTATION BREEDING.
E.g.- X-RAYS CAUSING MUTATION IN CEREALS.

7. BASED ON TISSUE OF ORIGIN
1. SOMATIC MUTATION- OCCUR IN SOMATIC CELLS &
AREN’T PASSED TO OFFSPRING.
2. GERMINAL MUTATION- OCCUR IN GAMETIC CELLS
OR REPRODUCTIVE CELLS (EGGS & SPERM) & ARE
PASSED TO OFFSPRING.

8. BASED ON DIRECTION
1. FORWARD MUTATION- OCCURS FROM THE NORMAL
ALLELE TO MUTANT ALLELE.
2. REVERSE MUTATION- OCCURS FROM THE MUTANT
ALLELE TO NORMAL ALLELE.

9. BASED ON TRAIT AFFECTED
1. VISIBLE MUTATION- AFFECTS ON PHENOTYPIC CHARACTER
& CAN BE DETECTED BY NORMAL OBSERVATION.
2. BIOCHEMICAL MUTATION- AFFECTS ON PRODUCTION OF
BIOCHEMICALS & NOT ON PHENOTYPIC CHARACTER.

10. ARE MUTATIONS HELPFUL OR HARMFUL?
• MUTATIONS HAPPEN REGULARLY
• ALMOST ALL MUTATIONS ARE NEUTRAL.
• MANY MUTATIONS ARE REPAIRED BY ENZYMES.
• MOST MUTATIONS HAVE HARMFUL EFFECT BUT SOME
ARE BENEFICIAL.
• SOME TYPE OF SKIN CANCERS & LEUKEMIA RESULT
FROM SOMATIC MUTATIOS.
• SOME MUTATIONS MAY IMPROVE AN ORGANISM’S
SURVIVAL (BENEFICIAL).

11. TYPES OF MUTATION
CHROMOSOMAL
MUTATION
1. STRUCTURAL
ABNORMALITIES
i. DELETION
ii. DUPLICATION
iii. INVERSION
iv. TRASLOCATION
2. NUMERICAL DISORDERS
i. NONDISJUNCTION
GENE MUTATION
1. POINT MUTATION
i. NONSENSE
ii. MISSENSE
iii. SILENT
2. FRAMESHIFT
MUTATION
i. INSERTION
ii. DELETION

12.  MAY INVOLVE:
- CHANGING IN STRUCTURE OF
CHROMOSOME
- LOSS OR GAIN OF PART OF CHROMOSOME

13. DELETION
• DUE TO BREAKAGE
• A PIECE OF CHROMOSOME IS LOST

14. DUPLICATION
OCCURS WHEN A GENE SEQUENCE IS
REPEATED

15. INVERSION
• CHROMOSOME SEGMENT BREAKS OFF
• SEGMENT FLIPS AROUND BACKWARD
• SEGMENT REATTACHES

16. TRANSLOCATION
• INVOLVES TWO CHROMOSOMES THAT AREN’T
HOMOLOGOUS
• PART OF ONE CHROMOSOME IS TRANSFERRED TO
ANOTHER CHROMOSOME

18. NONDISJUNCTION
• FAILURE OF CHROMOSOME TO SEPARATE DURING
MEIOSIS OR MITOSIS
• CAUSES GAMETE TO HAVE TOO MANY OR TOO FEW
CHROMOSOMES
• DISORDERS-
• KLINEFELTER’S SYNDROME –XXY
• DOWN SYNDROME –THREE 21ST CHROMOSOMES
• TURNER SYNDROME –SINGLE X CHROMOSOME

20. GENE MUTATION
IT IS A PERMANENT ALTERATION IN THE
DNA SEQUENCE THAT MAKES UP A GENE
OR CHANGE IN NUCLEOTIDE SEQUENCE
OF A GENE.
THEY CAN AFFECT ANYWHERE FROM A
SINGLE DNA BUILDING BLOCK(BASE PAIR)
TO A LARGE SEGMENT OF A
CHROMOSOME THAT INCLUDES MULTIPLE
GENES.

21. POINT MUTATION
INCLUDES A SINGLE NUCLEOTIDE BASE SUBSTITUTION
OF THE GENETIC MATERIAL,DNA OR RNA.
SICKLE CELL DISEASE IS
THE RESULT OF ONE
NUCLEOTIDE SUBSTITUTION
OCCURS IN HEMOGLOBIN GENE

22. NONSENSE MUTATION
CODE FOR A STOP,WHICH CAN TRUNCATE
THE PROTEIN.A NONSENSE MUTATION
CONVERTS AN AMINO ACID CODON INTO
A TERMINAL CODON.THIS CAUSES THE
PROTEIN TO BE SHORTENED BECAUSE OF
THE STOP CODON INTERRUPTING ITS
NORMAL CODE.

23. MISSENSE MUTATION
CODES FOR A DIFFERENT AMINO ACID.
IT IS A TYPE OF NONSYNONYMOUS
SUBSTITUTION.
SILENT MUTATION
CODE FOR THE SAME AMINO ACID.A
SILENT MUTATION HAS NO EFFECT ON THE
FUNCTIONING OF THE PROTEIN.IT IS A
TYPE OF SYNONYMOUS SUBSTITUTION.

25. FRAMESHIFT MUTATION
• INSERTING OR DELETING OF A NUMBER OF
NUCLEOTIDES IN A DNA SEQUENCE THAT IS NOT
DIVISIBLE BY 3.
• CHANGES THE READING FRAME LIKE CHANGING A
SENTENCE
• PROTEINS BUILT INCORRECTLY
• ORIGINAL
• THE FAT CAT ATE THE WEE RAT.
• FRAMESHIFT MUTATION(“T”DELETED FROM CAT)
• THE FAT CAA TET HEW EER AT.

26. INSERTION MUTATION
INSERTION MUTATION IS THE ADDITION
OF ONE OR MORE NUCLEOTIDE BASE
PAIRS INTO A DNA SEQUENCE.
INSERTIONS CAN BE PARTICULARLY
HAZARDOUS IF THEY OCCUR IN AN
EXON,THE AMINO ACID CODING REGION
OF A GENE.

28. DELETION MUTATION
A SEQUENCE OF DNA IS LOST DURING
DNA REPLICATION.
SMALL DELETIONS ARE LESS LIKELY TO BE
FATAL,LARGE DELETIONS ARE USUALLY
FATAL.