Genetics

ASEMINAR

ONGENETICS AND HUMAN AFFAIRS

PROF. J. P. SHARMA ( DIRECTOR)

DR. R. .K. RAO ( PRINCIPAL)

Guided by - AJAY SINGH (HOD)

PRESENTED BY..

NIKITA DEWANGAN

M.Sc.1STSEM

BIOTECHNOLOGY

G.D. RUNGTA COLLEGE OF SCIENCE & TECHNOLOGY

KOHKA-KURUD,BHILAI DURG (C.G.)

GENETICS AND HUMAN AFFAIRS

Introduction

Definition

Terminology

What is human affairs?

Genetics and health

Human genome project

Gene therapy

Conclusion

References

SYNOPSIS

1


The branch of biology that deals with heredity,

especially the mechanisms of hereditary transmission

and the variation of inherited characteristics among

similar or related organisms.

INTRODUCTION

2


Chromosomes.

Gene.

Alleles - Homozygous.

- Heterozygous.

Nucleotides.

Codon.

Genetic Code.

TERMINOLOGY

3


Chromatin: DNA, RNA & proteins that make up chromosome.

Chromatids: one of the two identical parts of the chromosome.

Centromere: the point where two chromatids attach

46 chromosomes. 22 pairs Autosomes and 1 pair Sex chromosomes.

CHROMOSOMES

4Fig 1 chromosome structure

NUCLEOTIDE : Group of molecules that when linked together, form

the building blocks of DNA and RNA; composed of phosphate group,

the bases : adenosine, cytosine, guanine and thymine and a pentose

sugar. In case of RNA, thymine base is replaced by uracil.

CODON : Series of three adjacent bases in one polynucleotide

chain of a DNA or RNA molecule which codes for a specific

amino acid.

GENETIC CODE : The sequence of nucleotides in a DNA or RNA

molecule that determines the amino acid sequence in the synthesis

of proteins.

CHROMOSOMES

GENETICS AND HUMAN AFFIRS

5


Biological unit of heredity.

Gene hold the information to build and maintain their cells and pass genetic traits to offsprings.

In cells, a gene is portion of DNA.

GENE

6Fig. 2 gene structure


Is one member of a pair or series of different forms of a gene.

Homozygous - An organism in which 2 copies of genes are

identical i.e. have same alleles.

Heterozygous - An organism which has different alleles of the

gene.

ALLELE

7

GENETICS AND HUAMN AFFAIRS

Genetics seems to hold a special place in human affairs.

Not only is it relevant in the same sense that other

scientific disciplines are but it also has much to tell us

about the nature of our humanity and in this sense the

biological science.

HUMAN

AFFAIRS

8


Congential Disease. Diseases which are present at birth.

Hereditary/Familial Disease. Diseases which are derived from one’s parents and trasmitted in the gametes through the generations.

GENETICS

AND

HEALTH

9


Classification of diseases based on their genetic basis :

Monogenic (Mendelian) disorders

Chromosomal aberrations

Polygenic disorders

GENETIC

DISEASES

10


4 general patterns of inheritance are observed :

Autosomal recessive

Autosomal dominant

X-linked recessive

X-linked dominant

MENDELIAN

DISORDER

11


Autosomal recessive The disease appears in

male and female children

of unaffected parents.

e.g., Sickle cell anaemia,

Phenylketonuria

MENDELIAN

DISORDER

12

Fig. 3 autosomal recessive


Autosomal dominant

Affected males and females

appear in each generation of the

pedigree.

Affected mothers and fathers

transmit the phenotype to both

sons and daughters.

e.g., Neurofibromatosis, Adult

polycystic kidney disease.14

MENDELIAN

DISORDER

13Fig . 4 autosomal domonant


X-linked recessiveMany more males than

females show the disorder.

All the daughters of an

affected male are

“carriers”.

None of the sons of an

affected male show the

disorder or are carriers.

e.g., Hemophilia , Colour

blindness 15

MEDELIAN

DISORDER

14Fig.5 x- linked recessive


X-linked dominant Affected males pass the

disorder to all daughters but

to none of their sons.

Affected heterozygous

females married to

unaffected males pass the

condition to half their sons

and daughters

e.g. Vitamin D resistant

rickets.

16

MENDELIAN

DISORDER

15Fig. 6 x – linked dominant


Alternations in the number or structure of chromosomes

Autosomes or sex chromosomes

Numerical abnormalities –

o Euploidy

o Trisomy (2n+1) : Klienfelter’s syndrome

o Monosomy (2n-1) : Turner’s syndrome

Structural abnormalities - breakage followed by loss or rearrangement

deletion, translocation.

CHROMOSOMAL

ABERRATIONS

16


Point Mutation:o Substitution of a single

nucleotide base by a different base.

Silent Mutation. Missense Mutations.

Nonsense Mutations.

CHROMOSOMAL

MUTATION

17Fig.7 point mutation


Frameshift mutation

Insertion or deletion

of one or two base

pairs alters the

reading frame of the

DNA strand.

CHROMOSOMAL

MUTATION

18Fig.8 frameshift mutation


Trinucleotide repeat mutation

Set of genetic disorder caused by trinucleotide repeat in certain genes exceeding normal, stable threshold e.g. Fragile X Syndrome.

CHROMOSOMAL

MUTATION 19Fig.9 trinucleotide repeat mutation


HGP primarily found by the Us government, department of energy, genome centre and the goals of project are as follows.

To develop a genetic linkage map of human genome by identifying thousands of genetic material and mapping them in the genome.

To obtain a physical map of human genome by cloning genomic DNA into cosmids.

To sequence the entire human genome.

GENOME MAPPING

Molecular marker have been used to produce maps of all the human chromosomes in which markers are locate only one centimorgen(cM) apart . Therefore new DNA sequence can be easily linked with these markers.

HUMAN

GENOME

PROJECT 20


GENOME SEQUENCING

The DNA fragments used for sequencing are generally obtained by

shotgum approach; In which DNA fragments generated from a

given source e.g. whole genomic DNA, or a cosmid clone are cloned

and sequenced at random. As a result a DNA fragment is ordinarily

sequenced more than one and the various fragments belong to random

locations in the DNA source.

HUMAN

GENOME

PROJECT

21


Gene Therapy Introduction of normal genes into

cells that contain defective genes to reconstitute a missing protein product.

Gene therapy is used to correct a deficient phenotype so that sufficient amounts of a normal gene product are synthesized to improve a genetic disorder.

Modification of cells by transferring desired gene sequences into the genome.

Two types of gene therapy - 1) Somatic gene therapy

2) Germ line gene therapy

G ENE

THE R A P Y

22Fig . 10 gene therapy


Genetics is the study of how living things receive common traits from

previous generation. These trait are described by the genetic

information.

Human genetics is concerned with the inheritance of human traits and

their relationship to human health. It deals with the hereditary disorders

and provide key to their prevention and control.

CONCLUSION

23


B. D. SINGH 2010 GENETICS

P. K. GUPTA 2007 GENETICS

SOME CONTAIN FROM NET -

byjus.com/biology/genetics

REFRENCES

24

THANK YOUTHANK YOU

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Genetics

Healthcare