MUTATION,CHROMOSOMAL MUTATION &GENE MUTATION

CHROMOSOMAL MUTATION &GENE MUTATION
ITS EFFECT ON CHROMOSOME&SYNDROME DISEASE
EFFECT ON PLANT

1. WELCOME PRESENTED BY HEMANT DARJI

2. GOVIND GURU TRIBLE UNIVERSITY,BANSWARA SUBMITTED TO: DR.JAYANA UPADHYAY SUBMITTED BY: HEMANT DARJI M.SC.(BOTANY) 2 nd SAMASTER TOPIC=MUTATION

3. mutation INTRODUCTION The term “MUTATION” was first coined by scientist Hugo De Vries in 1901. A mutation is a change in the genetic material . This means changes to the DNA or to the chromosomes which carry the DNA. These changes are heritable (can be passed on to the next generation) unless they have lethal effects.

4. ROLE OF MUTATION Ultimate source of all genetic variation and it provides the raw material for Evolution Some mutations lead to newer versions of proteins and help the organisms to adapt to changes in the environment. As the first step of evolution, the mutation is important as it creates a new DNA sequence for a specific gene which creates a new allele .

5. CHANGE IN THE STRUCTURE OF A CHROMOSOME May Involve: Changing the structure of a chromosome The loss or gain of part of a chromosome

6. Chromosome Mutations Four types exist: Deletion Inversion Duplication Translocation

7. Deletion Due to breakage A piece of a chromosome is lost.

8. 2 .Inversion Chromosome segment breaks off Segment flips around backwards Segment reattaches

9. 3.Duplication Occurs when a gene sequence is repeated.

10. 4.Translocation Involves two chromosomes that are NOT homologous. Part of one chromosome is transferred to another chromosome..

11. CHANGE IN THE NUMBERS OF CHROMOSOME

12. EUPLOIDY Euploidy is a chromosomal variation that involves the entire set of chromosomes in a cell or an organism. Euploidy is more tolerated in plants than in animals. There may be a single set ( monoploidy ), two sets ( diploidy ), or multiple sets (polyploidy, i.E. Triploid, tetraploid , pentaploid , hexaploid , etc.)

13. 1.MONOPLOIDY Monoploids have a single basic set of chromosomes. E.G.- Barleyand 10in corn. Monoploidy is common in plant and raer in animal. Monoploids can be produced by artificial mean by the following methods:- X-rays treatment Delayed pollination Temperature shock (cold treatment) Colchicine treatment Distinct hybridization

14. 2.POLYPLOIDY Polyploidy occurs in cells and organisms when there are more than two homologous sets of chromosomes. Very common in plants – associated with origin of new species – may positively correlate to size of individual. There are two classes of polyploids based on the number of chromosome sets: • . Even-number polyploids are more likely to be at least partially fertile, because the potential exists for equal segregation of homologs during meiosis. . Odd-number polyploids will always have unpaired chromosomes. Balanced gametes are rare and these organisms are usually sterile or have increased zygote death. Triploids, pentaploids (all with odd number of chromosome sets) are often sterile due to pairing problems during meiosis.

15. Polyploidy occurs in two types in plants . Types of polyploidy in plants.. 1.Autopolyploidy -Autopolyploids results when all sets of chromosomes are from the same species, usually due to meiotic error. Examples include: – (1) “Seedless” fruits like bananas (3n = 33), grapes and watermelons. – (2) Grasses, garden flowers, crop plants and forest trees 2.Allopolyploidy – hybrid of two or more closely related species – partially homologous chromosomes ( homeologous ) Allopolyploidy is caused by the presence of several genomes of different species in a cell, a tissue or a whole organism.

16. ANUEPLOIDy This is a condition where the chromosome number is not an exact multiple of the normal diploid number, with either fewer or more than the normal number of chromosome in the cell. A condition of aneuploidy may occur due to loss of one or more chromosomes during mitosis or meiosis.

17. In diploid organisms aneuploid variations take four main forms that can be classified under two main groups: Hypoploidy : loss of one or more chromosomes from basic set.(called monosomy ).(2n-1) or due to the lose of one pair of chromosome called nullysomy (2n-2). Hyperploidy : presence of one or more chromosomes in the basic set.(called trisomy ).(2n+1).or a pair of chromosomes called tetrasomy (2n+2)

18. GENE MUTATIONS Change in the nucleotide sequence of a gene May only involve a single nucleotide May be due to copying errors , chemicals , viruses , etc.

19. 1.POINT MUTATION Point mutations are the most common type of gene mutation. Also known as base pair substitution. Change in a single nucleotide base pair. Point mutation can be categorized into three types: SILENT MUTATION MISSENSE MUTATION NONSENSE MUTATION

20. a. SAILENT MUTATION A silent mutation is a change in the sequence of nucleotide bases which constitutes DNA , without a subsequent change in the amino acid or the function of the overall protein. Sometimes a single amino acid will change, but if it has the same properties as the amino acid it replaced, little to no change will happen .

21. b.MISSENSE MUTATION : a base is substituted that alters a codon in the mRNA resulting in a different amino acid in the protein product TCA AGT UCA T T A A A T U U A Ser Leu

22. c.NONSENSE MUTATION : changes a sense codon into a nonsense codon . Nonsense mutation early in the mRNA sequence produces a greatly shortened & usually nonfunctional protein TCA AGT UCA T G A A C T U G A Ser Stop codon

23. A frameshift mutation is a genetic mutation caused by a deletion or insertion in a DNA sequence that shifts the way the sequence is read . 2FRAMESHIFT MUTATION

24. REPLACEMENT OF NUCLEOTIDE Transition : Purine is replaced with a purine Pyrimidine is replaced with a pyrimidine BASE SUBSTITUTION ARE MUTATION IN WHICH ONE BASE PAIR IS REPLACED BY ANOTHER . A G G A C C T T

25. Transversions : A purine is replaced by a pyrimidine A C A T G G C T C G C A T G T A or a pyrimidine is replaced by a purine

26. According to the survival (effects), mutations are classified into following four types: Lethal : A mutation which kills the individual that carries it . Sub-lethal: When mortality is more than 50% of individuals that carry mutation Sub-vital : When morality is less than 50% of individuals that carry mutation Vital: When all the mutant individual survives

27. According to the mode of origin mutation may be… A. SPONTANEOUS MUTATION : The mutation that occurs spontaneously is termed as spontaneous mutation. Most of the mutation that originally studied occurs spontaneously . B. INDUCED MUTATIONS: When mutations occur by treating an organism with mutagenizing agent is termed as induced mutation.

28. A mutagen is any substance or agent that can cause a mutation, or change in the sequence or structure of DNA. MUTAGEN Physical mutagens • Ionizing radiations such as X-rays, gamma rays causes DNA breakage and other damages. • Ultraviolet radiations with wavelength above 260 nm are absorbed strongly by bases, producing pyrimidine dimers , which can cause error in replication .

29. CHEMICAL MUTAGENS

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