The topic of discussion here is about Mutation & different types of mutation in organism, their effects & Mutational theory of evolution. Further the changes in the Number of chromosomes due to mutation and its effects & Mendelian disorders & their patterns of inheritance including the numerical abberations in chromosomes & the disorders associated with it.

2. GENETIC VARIATIONS

3. RECOMBINATION

4. RECOMBINATION
• The organisms which express characters of both the parents are known as recombinants. The
events responsible for mixing maternal and paternal characters in sexually reproducing organisms
are called Recombinations.
• New combinations appear in three ways :
• By independent assortment of chromosomes at the time of gamete formation.
• By random fertilization.
• By reciprocal recombination of linked genes in chromosomes by crossing over in Prophase-I of
meiosis.

5. MUTATION

6. MUTATION
Mutation theory was put forward by Huge de Vries.
The mutation can be defined as sudden, stable discontinuous and inheritable variations which appear in organism
due to permanent change in the phenotype.
The product of mutation is called Mutant. Mutations are responsible for the origin of new traits in the race and
therefore the mutation are the source of all variations.
Mutations occur in different type of cells
• Somatic mutation : In somatic cells
• Germinal Mutation : Occur in germ cells.

7. MUTATION
• Mutations produce different types of effects e.g : deleterious, lethal, advantageous and neutral,
visible or invisible.
• Most of the mutations occur in recessive genes and are not expressed, while some take place in
dominant genes and appear in mutants.
• Mutations have been occurring in nature also and are called Spontaneous mutations, when
numerous physical and chemical agents are used to increase the frequency of mutations, they are
called Induced mutations.

8. MUTATION
• Two types of mutations are recognised
• Gene or Point mutations
• Chromosomal mutations

9. GENE MUTATION/POINT MUTATION
• Gene or Point mutations are stable changes in genes i.e. DNA chain. The point or gene
mutation means the process by which new alleles of a gene are produced.
• The smallest part of gene that can mutate is called a Muton, the smallest muton in a gene is a
single base pair of DNA.

10. CHROMOSOMAL MUTATIONS OR ABERRATIONS
• A gene mutation alters the information conveyed by a gene, it alters the message. Chromosomal
mutation alters the number or position of existing genes.
• They may involve a modification in the morphology of chromosome or a change in number of
chromosomes.

11. CHROMOSOMAL MUTATIONS
• Morphological modification of Chromosome
• Such modifications may be intrachromosomal or interchromosomal. Following types can be
identified.
• Deletion : Sometimes a segment of chromosome breaks off and get lost. Deficiency generally
proves lethal or semilethal. If the terminal segment of the chromosome is lost it is called
deficiency and if intercalary segment is lost it is called deletions.

12. CHROMOSOMAL MUTATIONS
• Duplication : In this deleted chromosome segment is attached to its normal homologous
chromosome. Here a gene or many genes are repeated twice or more times in the same
chromosome. Duplication is more significant than deficiency and has been noticed in giant
chromosomes of salivary glands of Drosophila.
SALIVARY GLAND CHROMOSOME

13. CHROMOSOMAL MUTATIONS
• Translocation : If the broken end of a chromosome joins to another non-homologous
chromosome it is referred to as Translocation. An exchange of parts between two non-
homologous chromosomes is called reciprocal translocation.
• In simple translocation a segment of one chromosome breaks and is transferred to another non-
homologous chromosome as a result one chromosome represents deletion, while other has an
additional segment.

14. CHROMOSOMAL MUTATIONS
• Inversion : In case if there is a break in the chromosome , the centre piece may get inverted.
• Deletions & Duplications usually take place due to defect in crossing over i.e, a part lost by a
non-sister chromatid may be gained by the other chromosomal mutations causes the genes to be
lost or moves them in new location.

15. PEDIGREE ANALYSIS

16. PEDIGREE ANALYSIS
Study of the family history about inheritance of a particular trait provides information about the
flow of traits in successive generations. Such an analysis of traits in a several of generations of
a family is called the pedigree analysis.

17. SYMBOLS USED IN PEDIGREE ANALYSIS

18. AUTOSOMAL DOMINANT & RECESSIVE
DISORDERS

19. AUTOSOMAL DOMINANT & RECESSIVE
DISORDER

20. SOME MENDELIAN DISORDERS

21. HAEMOPHILIA

22. BLOOD CLOTTING

23. BLOOD CLOTTING CASCADE

24. HAEMOPHILIA

25. TYPES OF HAEMOPHILIA

26. INHERITANCE PATTERN

27. SICKLE CELL ANEMIA

28. SICKLE SHAPED RBC’s

29. AMINO ACID CHANGE CAUSE SICKLE CELL ANEMIA

30. INHERITANCE PATTERNS

31. PHENYLKETONURIA

32. NORMAL METABOLISM OF PROTEINS

33. PHENYLKETONURIA
Phenylpyruvic acid

34. INHERITANCE PATTERN

35. NUMERICAL CHANGES IN CHROMOSOMES

36. NUMERICAL CHANGES IN CHROMOSOMES

37. CHROMOSOMAL DISORDERS

38. DOWN’S SYNDROME

39. KLINEFELTER’S SYNDROME

40. TURNER’S SYNDROME

41. THANK YOU