Gene structure and function involves terminology like genes, alleles, genotypes and phenotypes. A gene is a segment of DNA that determines a trait and occupies a locus on a chromosome. It consists of coding exons and non-coding introns. Genes control DNA and RNA functions and consist of instructions for specific functions. Genes are passed from parents to offspring in dominant, recessive, autosomal or sex-linked inheritance patterns, which can result in genetic disorders. Single gene disorders are caused by mutations in a single gene.

1. Gene structure
and function

3. Terminologies in genetics

4. Terminology

5. Gene
• Gene is the hereditary determining factor and it consists of a
continuous segment of DNA.
the gene occupies in a specific
position on the chromosome
called locus (plural loci).

7. Structure of gene
• Made up of a long strand of DNA
• With coding sequences called
Exons and intervening non
coding sequences called introns

8. Allele

11. Allele

12. Dominant and recessive allele

17. Homozygous

20. Heterozygous

21. Dominence

22. Recessiveness

23. Hybridization

24. Monohybrid

25. Dihybrid

26. Function s of gene
• Genes control the functions of DNA and RNA.
• Genes consist of a particular set of instructions or specific
functions

28. Genotypeand phenotype

31. Pedigree

32. Genetic disorders
•a gross chromosomal abnormality involving the
addition or subtraction of an entire chromosome
or set of chromosomes.
•A genetic disease is any disease caused by an
abnormality in the genetic makeup of an
individual.

33. Inheritance
• Passing of genetic informations from one generation to other
generation
• Types
1. Dominent inheritance
2. Recessive inheritance
Autosomal
Sex linked
3. Sex linked inheritance

34. •Single gene inheritance is also called Mendelian
or monogenetic inheritance.
•Changes or mutations that occur in the DNA
sequence of a single gene cause this type of
inheritance.
•single-gene disorders. These disorders are
known as monogenetic disorders (disorders of a
single gene).

35. Dominant inheritance
•A dominant gene for a given character always get
inherited
•Or affected person have an affected parent

36. Autosomal dominant inheritance
• in which only one copy of a defective gene (from either parent)
is necessary to cause the condition;

38. Common genetic disorders

46. Autosomal recessive inheritance
• in which two copies of a defective gene (one from each parent)
are necessary to cause the condition;

49. Common autosomal recessive disorders
•Hemochromatosis
•Glycogen storage disease
•Thalassemia
•Alkaptonuria
•Muscular dystrophy
•Adrenal hyperplasia

50. Hemochromatosis

51. Glycogen storage disease

52. Thalassemia

53. Alkaptonuria

54. Muscular dystrophy

55. Adrenal hyperplasia

56. X-linked inheritance
• in which the defective gene is present on the female, or X-
chromosome. X-linked inheritance may be dominant or
recessive.

61. Mutation

63. Chromosomal aberrations

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