1. Online Counseling Resource YCMOU ELearning Drive… School of Architecture, Science and Technology Yashwantrao Chavan Maharashtra Open University, Nashik – 422222, India 1

2. OC-SBT083-CP1-01 Introduction Programmes and Courses  SEP – SBT083 – Unit 01 2

3. School of Science and Technology, Online Counseling Resource… Credits  Academic Inputs by Arun Punaji More. M.Sc. (Microbiology) ‏ Experience: 11 Years arunmesh@hotmail.com 3

4. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.4 How to Use This Resource  Counsellor at each study centre should use this presentation to deliver lecture of 40-60 minutes during Face-To-Face counselling.  Discussion about students difficulties or tutorial with assignments should follow the lecture for about 40-60 minutes.  Handouts (with 6 slides on each A4 size page) of this presentation should be provided to each student.  Each student should discuss on the discussion forum all the terms which could not be understood. This will improve his writing skills and enhance knowledge level about topics, which shall be immensely useful for end exam.  Appear several times, for all the Self-Tests, available for this course.  Student can use handouts for last minutes preparation just before end exam. 4

5. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.5 Learning Objectives  After studying this module you should be able to Describe contribution of Mendel in the development of classical genetics Describe the basic terminology in genetics Describe the basic concepts in genetics 5

6. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.6 Introduction - 1  Genetics is study of inheritance of variations in characteristics of organisms.  To understand how this variations are passes from generation to generation one need to understand the biological molecule called as Deoxyribonucleic acid, genes and their forms called as alleles, different mechanisms of occurrences of variations either due to mutations or genetic recombinations.  In this module the basic concepts and terminology of genetics are explained. 6

7. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.7 Introduction to Genetics-1  The thinking on inheritance of characteristics of parents to their offspring and emergence of variations in offspring began by the 1859 when Charles Darwin published his thinking on inheritance of characteristics in his book “Origin of Species ”.  Darwin presented the model of inheritance based upon his assumption of blending of inheritance in this book.  According to Darwin's theory offspring obtain the blend of their parents' characters 7

8. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.8 Introduction to Genetics-2  Mendel in 1856 carried out numerous experiments on pea plants to study the passing of characters from parents to their offspring  He concluded that a character is passed intact from parents to their offspring as a discrete particle to which he used to referred as factor.  Thus Mendel clearly disproved the blending inheritance theory put forth by Darwin. 8

9. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.9 Terminology of Genetics-1  Gene:- Gene is nucleotide sequence of DNA molecule which encode a single functional peptide chain. A single gene exist in two forms called as alleles of that gene. One allele is dominant among the pair of alleles of the gene. 9

10. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.10 Terminology of Genetics-2  Genotype :- Genotype is total set of genes received from parents. Genotype of a particular species always remain same. Genotype can be described as homozygous and heterozygous. Homozygous genotype contain the same type of alleles of a gene. Heterozygous genotype contain the two different types of alleles of a gene. 10

11. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.11 Terminology of Genetics-3  Phenotype:- Phenotype is collection of biological characteristics including appearances, chemical, biological and behavior attributes expressed by a organism.  Character is a feature e.g flower color.  Whereas the trait is a particular form of a character e.g. yellow color.  There are two genes (alleles) for a single trait.  For example character height has two traits, tall and short.  Thus the trait tall has two genes and can be represented s “Tt” where “T” is dominant gene and “t” is called as recessive gene. 11

12. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.12 Terminology of Genetics-4  Chromosomes:- a Chromosome is DNA molecule which is highly folded into a compact structure associated with number of proteins molecules such as histones. 3=4= chromatids 2= centromere 12

13. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.13 Terminology of Genetics-5  Chromosomes:- structure of DNA 13

14. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.14 Terminology of Genetics-6  Autosomal chromosomes:- The chromosomes other than sex chromosomes are called as autosomal chromosomes. Human genome consist of 44 autosomal chromosomes. They are present in all cells. The autosomal chromosomes control the somatic characteristics.  Sex chromosomes:- The X and Y chromosomes are called as sex chromosomes. 14

15. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.15 Terminology of Genetics-7  Homologous chromosomes:- The chromosomes which have similar but not identical nucleotide sequences are called as homologous chromosomes. Homologous chromosomes are also similar in their structure, length. The homologous chromosomes pair with each other during meiosis due to their similarity in structure, length and nucleotide sequences. Due to this pairing among homologous chromosomes crossing over take place between them producing recombinant chromosomes. 15

16. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.16 Terminology of Genetics-8  Homologous chromosomes:-  Crossing over between homologous chromosomes during meiosis 16

17. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.17 Terminology of Genetics-9  Heterologous chromosomes:- The chromosomes having dissimilar nucleotide sequences are called as heterologous chromosomes. 17

18. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.18 Terminology of Genetics-10  Meiosis :- Meiosis is the process of gamete formation in which one member of chromosome pair is transmitted to gamete cells. In meiosis the diploid set of chromosomes is reduced to haploid set in the gametes. When the gametes or sex cells (egg and sperm cell) fertilized to form zygote, diploid cell. During meiosis a single diploid cell give rise to four haploid cells. Meiosis involve DNA replication. 18

19. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.19 Terminology of Genetics-11  Mitosis:- Mitosis is the process of cell division involving DNA replication. In mitosis diploid set of chromosomes of cell is maintained. 19

20. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.20 Terminology of Genetics-12  Mutation:- Abrupt change in the nucleotide sequence in DNA molecule which may or may not results into any phenotypic change. 20

21. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.21 Central Dogma of Molecular Biology  The genetic information stored in the sequences of DNA flow from DNA to RNA 21

22. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.22 Transcription  The process of synthesis of mRNAs from nucleotide sequences in DNA. 22

23. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.23 Translation  The process of synthesis polypeptide chain using nucleotide sequences in mRNA. 23

24. School of Science and Technology, Online Counseling Resource… What We Learn…..  Basic terms useful to understand the subject Genetic.  Contribution Mendel to the classical genetics.  The central dogma of molecular biology.  Meiosis and mitosis.  Recombination and mutation. 24

25. School of Science and Technology, Online Counseling Resource… Critical Thinking Question  What was the significance of discovery of factors governing the phenotypes? 25

26. School of Science and Technology, Online Counseling Resource… Hints for Critical Thinking Question Concept of meiosis Concepts of genes 26

27. School of Science and Technology, Online Counseling Resource… Study Tips  Book Title: Genetics Title: Genetics Author: Monroe W. Strickberger Author: Monroe W. Strickberger Publication: prentice-Hall of India private Limited Publication: prentice-Hall of India private Limited  Book Title: Principles of Genetics Author: Tamarin Author: Tamarin Publication: Tata Mcgrawhills Publication: Tata Mcgrawhills 27

28. End of the Presentation Thank You ! 28