This document discusses complementary and supplementary inheritance in genetics. It provides two examples of complementary inheritance - flower color in sweet peas, which is determined by two genes whose products interact, and pericarp color in barley. Both examples show a 9:7 ratio in F2 generations. Two examples of supplementary inheritance are also provided - comb type in chickens, which follows a 9:3:3:1 ratio, and coat color in mice, which follows a 9:3:4 ratio. Supplementary genes each produce an effect independently but combine to produce new traits.

1. COMPLEMENTARY INHERITANCE &
SUPPLEMENTARY INHERITANCE
SUBMITED BY,
M.THILAKAR,
BHARAHTIDSASAN
UNIVERSITY,
TIRUCHIRAPALLI
LS1154.

2. CELL : BASIC UNIT OF LIFE
 Cellls are the basic unit of
life.
 PROKARYTE : Less than
thousand of mm long and
lacks a complicated system
of internal membranes and
membranous organouls.
 EUKARYOTE : Larger then
prokaryotes. Contain
complicated internal
membranes.
 They contain Cytoplasm,
Nuleus, DNA, RNA, etc.,

3. CONT.....
 Hall mark of all Eukaryote cells is that their
Hereditary material is contained within a large
Membranes bounded strucuture called nucleus.
 Nuclei of Eukaryote cell is provoded a safe haven
for DNA, which is organised into discrete structure
called Cromosomes.
 Genes are located in Cromosome.
 Consisit of one Double Strand DNA molecule with
an assortment of Proteins.
 In Prokarytes : Plasmids – Circular.

4. Mendelism
 Father of Genetics.
 1822 – 1884.
 Gardening
 Pea plants.
 Natural History of
Society, Brunn.
 Correns,
 De vries,
 Tshermark @ 1900.

5. Pea Plant
 Pea plants are Self
Fertilizing plants.
 Cross ploniation is
not difficult.
 Artificial
Fertilzation is
almost success.
 Short Life cycles.

7.  Law of Dominance : Of the two alleles,
one Allele expresses its Character in F1.
 Law of Segregation : During Gamete
formation, the Genes of a pair separate in
Mieosis and each gamete receives only
one / gamete.
 Law of independent Assortment : genes
for each pair of character seperate
independently from those of other
characters during gamete formation.

8. COMPLEMENTARY INHERITANCE

9. COMPLEMENTARY GENES
 Two or More Allelic dominant genes
interact with each another to produce a
Character ;
 But one gene cannot produce that
character in the Absence of other.
 Action of these Independent genes are
Complementary.
 It’s a Non allelic gene Interaction.

10. Experiment 1 :
INERITANCE IN SWEET PEA PLANT
 Bateson and Punnet
 Flower color in Sweet pea plant,
Lathyrus odoratus.
 Two varieties of Flower colors.
1. Red color, 2. White color
Red color : due to te Pigment Anthocyanin,
from a colorless substance Chromogen by
the action of Enzyme.

11.  Parents : White x White
Ccaa x ccAA
GAMETES : Ca x cA
F1 : CcAa
Red
F1 x F1 :
Gametes : CA Ca ca ca
Chromogen + Enzyme = Anthocyanin.
 Gene C : Chromogen
 Gene A : Enzyme Ratio = 9 : 7

12. INHERITANCE OF FLOWER COLOR
IN SWEET PEA
 F2 :
GAMETES CA Ca Ca Ca
CA CCAA CCAa CCAa CcAa
RED RED RED RED
Ca CCAa Ccaa Ccaa Ccaa
RED WHITE RED WHITE
cA CcAA CcAa CcAa CcAa
RED RED WHITE WHITE
ca CcAa Ccaa Ccaa Ccaa
RED WHITE WHITE WHITE

13. RESULTS
 F2 GENERATIONS :
 RED = 9 WHITE = 7
 Ratio = 9:7
 Two or More Allelic dominant genes
interact with each another to produce a
SINGLE Character.
 But SINGLE gene cannot produce that
character in the Absence of other.
 Action of these Independent genes are
Complementary.

14. Experiment 2 :
PERICARP COLOR IN GRAINS OF
BARELY
 Two varieties of Pericarp colors in grains.
1. Red color, 2. White color.
 Red color : due to the Pigment
Anthocyanin, from a colorless substance
Chromogen by the action of Enzyme.
 If the enzyme absent, Anthocyanin can
not be synthesized in cells.
 So anthocyanin needs both of Chromogen
and enzyme.

15. PARENTS : WHTIE GRAIN x WHITE GRAIN
ReRejj x rereJJ
GAMETES : Rej x reJ
F1 : RereJj
Red Grain
F1 x F1 :
GAMETES : ReJ reJ ReJ reJ

16. INHERITANCE OF PERICARP COLOR IN
BARELY
F2
Ratio = 9 : 7
GAMETE ReJ Rej reJ Rej
S
ReJ ReReJJ ReReJj RereJj RereJj
RED RED RED RED
Rej ReReJj ReRejj RereJj Rerejj
RED WHITE RED WHITE
reJ RereJJ RereJj rereJJ rereJj
RED RED WHITE WHITE
Rej RereJj Rerejj rereJj rerejj
RED WHITE WHITE WHITE

17. RESULTS :
 F2 GENERATIONS :
 RED = 9 WHITE = 7
 Ratio =9:7
 Two or More Allelic dominant genes
interact with each another to produce a
SINGLE Character.
 But SINGLE gene cannot produce that
character in the Absence of other.
 Action of these Independent genes are
Complementary.

18. SUPPLLEMENTARY INHERITANCE

19. SUPPLLEMENTARY GENES
 Two independent pairs of dominant genes,
which interact in a such way that each
dominant gene produces its effect whether
the other is present or not.
 But even second dominannt gene is added
to first, a new character is expressed.
 Non allelic interactions

20. Experiment – 1
INERITANCE OF COMBS IN FOWLS
 Bateson and Punnet in 1908.
 In Fowls, Four types of Combs.
1. Rose, 2. Pea, 3. Walnut,
4.Single
 Rose – R, Pea – P.
 Rrpp Produces Single Comb type.
 If R + P = Walnut.

21.  PARENTS :
RED COMB MALE x PEA COMB FEMALE
RRpp x rrPP
GAMETES : Rp x Rp
F1 : RrPP
WALNUT
F1 X F1 :
GAMETES : RP Rp rP rp

22. INHERITANCE OF COMBS IN FOWLS
F2 :
GAMETES RP Rp rP rp
RP RRPP RRRp RrPP RrPp
Walnut Walnut Walnut Walnut
Rp RRpp RRpp RrPp Rrpp
Walnut ROSE Walnut ROSE
rP RrPP RrPp rrPP rrPp
Walnut Walnut PEA PEA
Rp RrPp Rrpp rrPp Rrpp
Walnut ROSE PEA Single

23. RESULTS :
 F2 GENERATIONS :
 WALNUT = 9 ROSE = 3
 PEA = 3 SINGLE = 1
 Ratio = 9 : 3 : 3 : 1
 Two independent pairs of dominant genes
interact in a such way.
 Each dominant gene produces its effect
whether the other is present or not.
 But even second dominant gene is added
to first, a new character is expressed.

24. Experiment – 2
Coat color in Mice
 Studied by Castle.
 3 Types of Mice :
1. Agouti, 2. Black, 3. Albino.
Agouti - Dominant to Black and Albino.
Albino - Recessive to Agouti and Balck.
Black - Dominant ot Albino and
Recessive to Agouti.

25.  PARENTS : BLACK MALE x ALBINO FEMALE
Bbaa x bbAA
 GAMETES : Ba x Ba
 F1 : BbAa
Agouti
F1 x F1 :
GAMETES : BA Ba bA ba

26. INHERITANCE IN COATS OF
MICE
GAMETE BA Ba bA ba
F2 : S
BA BBAA BBAa BbAA BbAa
AGOUTI AGOUTI AGOUTI AGOUTI
Ba BBAa Bbaa BbAa Bbaa
AGOUTI BLACK AGOUTI BLACK
bA BbAA BbAa bbAA bbAa
AGOUTI AGOUTI ALBINO ALBINO
ba BbAa Bbaa bbAa Bbaa
AGOUTI BLACK ALBINO ALBINO

27. RESULTS :
 F2 GENERATIONS :
o AGOUTI = 9 BLACK =3 ALBINO = 4
Ratio = 9 : 3 : 4
o Two independent pairs of dominant genes
interact in a such way.
 Each dominant gene produces its effect
whether the other is present or not.
 But even second dominant gene is added to
first, a new character is expressed.

28. REFERENCES
1. GENETICS By Dr. P MEYYAN,
SARAS PUBLICATION.
2. PRINCIPLES OF GENETICS By D PETER SNUSTAD
AND MICHAEL J SIMMONS
JOHN WILEY & SONS.

29. thank you……….