The basics of Genetics are explained in the presentation.

1. By: Kuljit kaur
(kuljitk03@gmail.com)

2. What is Mendalian genetics ?
Mendelian inheritance is a type
of biological inheritance that follows the
principles originally proposed by Gregor
Mendel in 1865 and 1866, re-discovered in 1900
and popularised by William Bateson.

3. Gregor Johann Mendel
• Austrian monk.
• Born on 22 July 1822.
• His father was peasant and his
grandfather was gardener.
• Was initially taught by local
priest but later on he was
admitted in an Institute of
Philosophy.
• He was not financially well to
do therefore in 1843, he
terminated his studies and went
back to monastery in Brunn.
• He was made incharge of
garden at the monastery and
named himself Gregor.

4. Gregor Johann Mendel
• He became priest in 1847
• After 4 years he went to
University of Vienna
where he studied physics,
mathematics , chemistry
and botany.
• When he returned to
monastery after completing
his studies , he took the
position as a teacher of
natural sciences at the
Technical School.

5. Why Mendel chose peas ?
• Mendel first started with mice. He
thought he would take mice with
different characters and make them
mate , look at their offsprings and
see if some pattern is there.
• He did the same thing in honeybees.
• Both experiments didn’t work out.
• The problem is you can’t control
when animals mate, right?
• Eventually Mendel turned towards
garden peas.
• He found peas were perfect for his
experiment.

6. Why Mendel chose peas ?
• Why peas exactly ?
• First it’s a plant he could control
mating/ fertilization.
• Peas have very short life cycle.
Only take 3 months to grow to full
height. Apple tree take 10 years so
apple tree would be the worst
candidate if you want to do a lot of
experiments.
• Pea plant have a lot of observable
contrasting characters to
experiments. Characters had only 2
contrasting traits.

7. 7 characters of pea plant

10. Conclusion

11. Terminology
• GENE:Gene is the shortest segment of DNA responsible for
the expression of its specific character.
• Gene is also called as the basic unit of heredity. It is small
DNA segment that determines a biological character of an
organism. Gene is situated on chromosomes.
• GENOME:It is the total genetic composition of an organism.
• ALLELE:Allele is an alternate form of the same gene in
which one is parental and other is maternal. In case of plant
height, tallness and dwarfness are the two alleles of a gene.

12. • DOMINANT ALLELE:Out of two alleles, the one that is
capable of expressing itself by hiding or suppressing its
contrasting allele is known as dominant allele.
• RECESSIVE ALLELE:Out of two alleles, the one that is being
suppressed by its alternative allele is called as recessive
allele.
• Recessive is an allele that does not express itself when
present with the dominant allele (in heterozygous form).
• HOMOZYGOUS:A diploid individual carrying two identical
alleles is known as homozygous.
• It is pure for a trait or character.

13. • HETEROZYGOUS:A diploid individual carrying two different
alleles is known as heterozygous or hybrid.
• It is impure for a trait (T t)
• GENOTYPE:A genotype is a genetic expression of an
organism.
• For plant height, TT, Tt and tt are the different genotype
• PHENOTYPE:It is the physical or the observable expression
of an organism.
• It is the observable characteristic of an individual.

14. • CHARACTER:It refers to a general feature of an
organism such as eye color, plant height etc.
• HYBRID:The product of a cross between two
genetically different individual belonging to the same
genus or species or between two different genera is
called hybrid.
• MONOHYBRID CROSS:A cross between the two
parents that are differing in one pair of alternating
(contrasting) character is called monohybrid cross.
• In this type, single character is used.

15. • DIHYBRID CROSS:A cross between the two parents that are
differing in two pairs of alternating character is called
dihybrid cross.
• In this type, two contrasting characters are used. For
example, seed shape and seed color (round yellow versus
wrinkled green)
• FILAL GENERATION:The progeny obtained as a result of
crossing between parents is a hybrid progeny and is called
First filial generation, represented by F1 (filial=offsprings).
• The progeny obtained as a result of self-fertilization among
F1 plants represents second filial generation represented as
F2.

16. Mendel’s Laws
Law of Dominance
Law of Segregation
Law of Independent
Assortment

17. Law of Dominance

18. Law of segregation
Law of segregation states
that allele pairs separate or
segregate during gamete
formation and randomly
unite at fertilization.

20. Law of Independent Assortment
• Mendel's law of independent
assortment states that the alleles of two (or
more) different genes get sorted into gametes
independently of one another. In other words,
the allele a gamete receives for one gene does
not influence the allele received for another
gene

23. Kuljit kaur
Lecturer
Kanya maha vidyalaya
(kuljitk03@gmail.com)