Genetics

A
SEMINAR
ON
GENETICS 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.)

 Introduction
 Definition
 Terminology
 What is human affairs?
 Genetics and health
 Human genome project
 Gene therapy
 Conclusion
 References
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 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.
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 Chromosomes.
 Gene.
 Alleles - Homozygous.
- Heterozygous.
 Nucleotides.
 Codon.
 Genetic Code.
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 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.
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Fig 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.
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GENETICS AND HUMAN AFFIRS
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 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.
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Fig. 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.
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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.
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 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.
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Classification of diseases based on their genetic basis :
 Monogenic (Mendelian) disorders
 Chromosomal aberrations
 Polygenic disorders
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4 general patterns of inheritance are observed :
 Autosomal recessive
 Autosomal dominant
 X-linked recessive
 X-linked dominant
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Autosomal recessive
 The disease appears in
male and female children
of unaffected parents.
 e.g., Sickle cell anaemia,
Phenylketonuria
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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.
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13Fig . 4 autosomal domonant

X-linked recessive
 Many 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
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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.
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Fig. 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.
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 Point Mutation:
o Substitution of a single
nucleotide base by a
different base.
 Silent Mutation.
 Missense Mutations.
 Nonsense Mutations.
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Fig.7 point mutation

 Frameshift mutation
Insertion or deletion
of one or two base
pairs alters the reading
frame of the DNA
strand.
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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.
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Fig.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.
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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.
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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
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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.
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 B. D. SINGH 2010 GENETICS
 P. K. GUPTA 2007 GENETICS
 SOME CONTAIN FROM NET -
byjus.com/biology/genetics
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