1. Multiple Alleles Remember: Chromosomes occur in pairs.
(homologous pairs)
the different alleles of a gene occupy the same positions on each chromosome

2. About 30% of the genes in humans are di-allelic, that is they exist in two forms, (they have two alleles)
About 70% are mono-allelic, they only exist in one form and they show no variation
A very few are poly-allelic having more than two forms
This is a controlled by a tri-allelic gene
It can generate 6 genotypes
The alleles control the production of antigens on the surface of the red blood cells
Two of the alleles are codominant to one another and both are dominant over the third
Allele IA produces antigen A
Allele IB produces antigen B
Allele i produces no antigen
The ABO blood system
© 2007 Paul Billiet ODWS

3. BASIC: ALEL DAN GEN GANDA
MonoHibrid pada Hewan:
Warna Rambut Hitam: (gen A):
AA (hitam) x aa (albino)
Aa (Hitam)
However, it is possible to have several different allele possibilities for one gene.
Multiple alleles is when there are more than two allele possibilities for a gene.
Gen A:
1 Kali mutasi : -- >alel a
Gen Ganda:
Bbrp kali mutasi---) bbrp alel: a1,a2,a3, dst

4. A L E L G A N D A Pengertian:
Gen (virgin) kalau bermutasi membentuk Alel ( A -- a)
Banyak Gen mengalami mutasi berulang-ulang, menimbulkan
banyak macam alel (lebih dari 2, disebut alel Ganda)
Contoh: Gen pigmentasi bulu kelinci (Gen C, pigmentasi hitam),
memiliki 3 alel:
c : albino (tak ada pigmentasi)
cch: pigmentasi terang, bulu pigmentasi gelap pada ujung (Chinchilla)
ch: pigmentasi bagian ujung-ujung tubuh, bagian lain putih
(H= himalaya)
Urutan dominasi alel : C>cch>ch>c

5. Certain types of rabbits…
…can either be brown, white, have a chinchilla pattern, or have a himalayan pattern
C causes fully brown coat
cc causes albino (white)
cch causes a chinchilla pattern
ch causes a Himalayan pattern
The alleles are arranged in the following pattern
 C > cch > ch > c
Full color rabbit – alleles are dominant to all others; CC, Ccch, Cch, or Cc
Chinchilla rabbit – partial defect in pigmentation
cch allele dominant to all other alleles except C; cchch, cchcch, or cchc
Himalayan rabbit – color in certain parts of the body; dominant only to c; chc or chch
Albino rabbit – no color – allele is recessive to all other alleles; cc

6. Kelinci lebih terang; Chinchila:
cch cchh; cch, ch; ccchc
Kelinci Gelap:
CC, Cc, Ccch, Cch
Kelinci Albino: cc
Kelinci Himalaya:
c h ch; ch,c
P ; CC x Cch Cch
F1 : C Cch x c c
F2: Cc
Cch c
P; Cch Cch X Ch Ch
F1: Cch Ch X Cch Ch
F2: Cch Cch
Cch Ch
Ch Ch

7. Multiple alleles dominance sex linkage multiple alleles d
Each gene locus can have more than 2 alleles.
An allele may be dominant to some alleles but recessive to others.
This situation produces more than 2 different phenotypes.
Each individual has 2 alleles present in their cells at any one time.
BB or Bb or Bbl
bb or bbl
blbl

8. Multiple gene inheritance
Cat coat colour is the result of the inheritance of a large number of different genes.

9. Blood Type In this case both A and B are dominant to O (recessive).
A and B are codominant (both expressed)
So... there are four human blood types
AA, AO A blood type
BB ,BO B blood type
AB AB blood type or
OO O blood type
Genotypes
Phenotypes (Blood types)
IA IA A
IA IB AB
IAi
IB IB B
IBi ii O

11. Sistem Golongan Darah A-B-O. (K. Landsteiner, 1868 – 1943)
Gen Asli I (Isoagglutinogen), :
Alelnya : Ia, Ib, I
Urutan dominan: Ia = Ib >i
Golongan (Fenotip)
Genotip A
Ia Ia atau Ia i B
Ib Ib; atau Ib i AB
Ia Ib O ii
Contoh: Gol A x Gol B
(Ia Ia; Ia I) x ( Ib Ib; Ib I)
Ia Ia x Ib Ib  AB
Ia Ia x Ib I  AB; A
Ia I x Ib I  AB; B
Ia I x Ib I  AB; A, B, O

12. Donor-recipient compatibility
Type A B AB O
Donor
Note:
Type O blood may be transfused into all the other types = the universal donor.
Type AB blood can receive blood from all the other blood types = the universal recipient.
= Agglutination
= Safe transfusion
© 2007 Paul Billiet ODWS

13. Crossing Over dan Rekombinan
Sometimes in meiosis, homologous chromosomes exchange parts in a process called crossing-over.
New combinations are obtained, called the crossover products.

14. Structure of Chromosomes
Homologous chromosomes are identical pairs of chromosomes.
One inherited from mother and one from father
made up of sister chromatids joined at the centromere.
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15. Chromosomes are matched in homologous pairs
MEIOSIS AND CROSSING OVER
Chromosomes are matched in homologous pairs
Each synapsis is made up of 2 pairs of sister chromatids
This matched set of 4 chromatids is called a tetrad
Chromosomes
Centromere
Sister chromatids
Figure 8.12

16. Crossing Over Basics
Occurs at One or More Points Along Adjacent Homologues
Points contact each other
DNA is Exchanged
Menaikkan var.Genetik
21 Apr 2002

17. Crossing over further increases genetic variability
Crossing over is the exchange of corresponding segments between two non-sister chromatids of homologous chromosomes
Genetic recombination results from crossing over during prophase I of meiosis
This increases variation further

18. Recombination During Meiosis
Recombinant gametes
The exchange of pieces
of homologous chromosomes
during formation of gametes.
A recombination between
2 genes occurred if the
haplotype of the individual
contains 2 alleles that resided in different haplotypes in the
individual's parent.
(Haplotype – the alleles at different loci that are received by an individual from one parent).

21. Two Loci Inheritance A A a a B B b b A a B b 4 b b 6 Recombinant 1 2 35 6
Recombinant

22. How crossing over leads to genetic recombination
Coat-color genes
Eye-color genes
How crossing over leads to genetic recombination
Nonsister chromatids break in two at the same spot
The 2 broken chromatids join together in a new way
Tetrad (homologous pair of chromosomes in synapsis) 1
Breakage of homologous chromatids 2
Joining of homologous chromatids
Chiasma
Separation of homologous chromosomes at anaphase I 3
Separation of chromatids at anaphase II and completion of meiosis 4
Parental type of chromosome
Recombinant chromosome
Recombinant chromosome
Parental type of chromosome
Gametes of four genetic types

23. Coat-color genes
Eye-color genes
A segment of one chromatid has changed places with the equivalent segment of its nonsister homologue
If there were no crossing over meiosis could only produce 2 types of gametes
Tetrad (homologous pair of chromosomes in synapsis) 1
Breakage of homologous chromatids 2
Joining of homologous chromatids
Chiasma
Separation of homologous chromosomes at anaphase I 3
Separation of chromatids at anaphase II and completion of meiosis 4
Parental type of chromosome
Recombinant chromosome
Recombinant chromosome
Parental type of chromosome
Gametes of four genetic types