Mendelian GeneticsGregor Mendel is recognized as the

father of genetics.

Mendel, who was not scientifically

trained, developed his theories in the

1850’s and 1860’s, without any

knowledge of cell biology or the science

of inheritance.Photo courtesy of Wikipedia.

In later years, genes, chromosomes, and DNA were

discovered and people began to understand how and why

Mendel’s theories worked.

Robert Bakewell1700sEnglish Breeder of:

Shire horsesLeicester sheepLonghorn cattle

Usedinbreedingprogeny testing

Gregor Mendel

basic genetic principlesused pea plantsnot well understood

during his life

Mendel, G. 1866. Experiments on Plant Hybridization. Transactions of the Brünn Natural History Society.

1 Introduction: History and Development of Genetics .

2. Mendelism :Monohibryd and dihibryd Inheritance,

3. Exception of Mendelsm : intermedier, linkage ,, sex

limited, sex inlfluenced

4. Genetic Material I: Chromosome, DNA and Gen ,

Abberation

5. Multiple Allel

6. Class Discusion: Proup of 5: Paper and PPT, Presentation.

Topic 1-5.

7. Class Discusion: Proup of 5: Paper and PPT, Presentation.

Topic 1-5.

8. MIDTEST

Topic of Discussion :Genetics of Animal

9. Probability in Genetics Inheritance

10. Sex Determination , linked and crossing over

11. Introduction to Genetics Population

12. Factors influencen in Population

13. Introduction to Genetics Engineering

14. Class Discusion: Proup of 5: Paper and PPT, Presentation.

Topic 1-5.

15. Class Discusion: Proup of 5: Paper and PPT, Presentation.

Topic 1-5.

16 FINAL TEST

Mendel’s experiments dealt with the

relationship between an organism’s genotype

and its phenotype.

Genotype – the genetic composition of an organism.

Phenotype – the observable or measurable characteristics

(called traits) of that organism.

The relationship between phenotype and genotype is

expressed as the following equation:

P = G + E

P = phenotype,

G = genotype, and

E = environment.

To understand Mendel’s principles and

the relationships between phenotype and

genotype, it is necessary to understand what makes

up the genetic material of animals and how this is

transferred from one generation to the next.

1. Nucleolus 5. Rough Endoplasmic Reticulum 9. Mitochondria

2. Nucleus 6. Golgi Aparatus 10. Vacuole

3. Ribosome 7. Cytoskeleton 11. Cytoplasm

4. Vesicle 8. Smooth Endoplasmic Reticulum 12. Lysosome

13. Centrioles

Genetics Vocabulary

• Homozygous- when both alleles of a pair are the

same for a gene• Homozygouse Dominant- PP

• Homozygous Recessive- pp

• Heterozygous- when the 2 alleles in the pair are

different for a gene• Heterozygous for flower color: Pp

Fertilization• Takes place when a sperm cell from a male reaches the egg

cell of a female

• The two haploid cells (the sperm and the egg) unite and form

one complete cell or zygote

• Zygote is diploid, it has a full set of chromosome pairs

• This results in many different combinations of traits in

offspring

Chromosomes

• Occur in pairs in the nucleus of all body cells except the sperm

and ovum

• Each parent contributes to one-half of the pair

• The number of pairs of chromosomes is called the diploid

number

• The diploid number varies species to species but is constant

for each species of animal

Cattle 30, Swine 19, Sheep 27, Goat 30, Horse 32,

Donkey 31, Chicken 39, Rabbit 22

Common Livestock Diploid Number

MENDELISME

Mendel proposed three principles to describe the transfer of genetic

material from one generation to the next.

• The Principle of Dominance : in a heterozygous organism,

one allele may conceal the presence of another allele.

• The Principle of Segregation: in a heterozygote, two different

alleles segregate from each other during the formation

• The Principle of Independent Assortment : the alleles

of different genes segregate, or assort, independently of each

other.

Later studies have shown that there are some important

exceptions to Mendel’s Principle of Independent Assortment, but

otherwise, these principles are recognized as the basis of

inheritance.

Dominant and Recessive Genes• In a heterozygous pair the dominant gene hides the effect

of its allele

• The hidden allele is called a recessive gene

• When working problems involving genetic inheritance the

dominant gene is usually written as a capital letter and the

recessive gene is written as a lowercase letter (PP,pp,pp)

• Black is dominant to red in cattle

• White face is dominant to color face in cattle

• Black is dominant to brown in horses

• Color is dominant to albinism

• Rose comb is dominant to single comb (chicken)

• Pea comb in chickens is dominant to single comb

• Barred feather pattern in chickens is dominant to nonbarred feather—the dominant gene is also sex-linked

• Normal size in cattle is dominant to ―snorter‖ dwarfism

Teories of Inheritance (Conventional)

Ovisma: pemilik sifat keturunan adalah ovum (♀ ),

fungsi jantan menghasilkan cairan untuk perkembangan ovum

Animalkulisma: pada cairan jantan ditemukan hewan2 kecil (Spz),

sbg pembawa sifat keturunan

Preformasi: Loewenhook: (mikroskop) ada MH kecil dalam spermatozoa atau ada manusia kecil dlm ovum

Epigenesis: Ovum terfertilisasi oleh Spz, kmd. tumbuh sedikir demi sedikit

Pangenesis (Darwin): dalam sel kelamin ♀ ♂ terdapat tunas 2 tumbuh

menjadi MH baru setelah fertilisasi

Plasma benih (Weisman): Gamet ♀ ♂ dibentuk oleh jar.khusus,

bukan jar. tubuh

Penelitian dan Peneliti Genetika

Mendel:•From Result of Mendel

•Then, What Is Genetic Factor ?

Genetic Materials ?

W. ROUX (1883): Cromosome

T. Bovery (1902): Gen bagian dari kromosom

Faktor Penentu (Gen/Kromosom) di wariskan lewat GAMET

(pada Anafase Meiosis I saat Separasi Kromosom homolog)

HIPOTESA SUTTON-T. BOVERY

HIPOTESA WS SUTTON-T . BOVERY:

1. Gen dibawa oleh kromosom

2. Satu pasang kromosom asal maternal+paternal

3. Pemindahan 1 ps kromosom saat meiosis

4. Sel benih mengandung kombinasi gen jantan dan betina

5. Kromosom homolog secara genetis berbeda,

sehingga sel benih scr genetis berbeda

6. Tiap kromosome terdiri lebih dari 1 gen,

gen-gen dalam kromosom pindah bersama-sama

Animal Chromosomes

TEORI : DOMONANSI-RESESIF

Sifat Tinggi : Dominan (gen T)

Sifat rendah/kerdil: Resesif (gen t)

Parents (P) TT

Gamet:T

X tt

Gamet: t

Filial 1 (F1)

Tt

HIBRIDA

♂/ ♀ T t

T TT Tt

t Tt tt

F2Fenotip: 3:1

Genotip : 1 : 2: 1

tt: homosigot

TT: homosigot

Tt: heterosigot

F2 ?

Monohibrid: 1 sifat beda

Di hibrid : 2 sifat beda

Tri hibrid : 3 sifat beda

HK.MENDEL I: Pemisahan Gen se alel

Dominansi penuh dan semi dominant

Dominansi Penuh

Parents (P) TT

Gamet:T

(Tinggi)

X tt

Gamet: t

(rendah)

Filial 1 (F1)

Tt

(Tinggi)

Bedanya ???

RR x rr

Merah putih

Rr

Roan/coklat

Semi Dominant:

Bunga pk 4.

Merah X Putih

Merah Muda

Kodominan

MONOHIBRID HEWANWarna rambut hitam (gen dominan A, pigmentasi melanin)

AA

Hitam

X aa

albino

F1 Aa

Hitam

Pada F2:

Fenotip : 3: 1

Genotip : 1 : 2 : 1

Macam sistim Persilangan1.Resiprok: Kebalikan ♀/

♂ ♂ HH x ♀ hh

Hh

Hasil sama

2. Back cross:

F1 dng parent ♂/

♀

Hasil:

Fenotip/genotip ttt.

3. Test Cross:

F1 dng P resesif

Pembuktian F1

homosigot

/heterosigot

Dihidrid pada hewan

Pada marmot:

•Rambut Hitam (gen H) vs putih (gen h)

•Rambut Kasar (gen K) vs rambut halus (gen h)

HH KK x hh kk

Gamet HK Gamet : hk

F1: Hh Kk x Hh Kk

Gamet HK Hk hK kk

HK * * * *

Hk * + * +

hK * * = =

kk * + = O

F2

Rasio fenotip : 9 : 3 : 3 : 1

Perhitungan Matematis (Rumus estimasi)

Juml.

Sifat

beda

Macam

gamet

F1

Kombi

nasi F2

Fenotip

F2

Kombi

nasi F1

Kombi

nasi

homosi

got

Genoti

p F2

n 2 n (2n)2 2n 2n 2n 3n

1 2 4 2 2 2 3

2 4 16 4 4 4 9

3 8 64 8 8 8 27

Macam Gamet:

Monohibrid (Aa) : 2 n = 2 1 = 2 = (A/a)

Dihibrid (AaBb) = 2 2 = 4 = (AB, Ab, aB, ab)

Tri hibrid (AaBbCc) 2 3 = 8 = (ABC, ….., abc)

Kombinasi:

Mono hibrid : (AaxAa)=(21)2 =4 =

(AA,Aa,Aa,aa)

Dihibrid (AaBbxAaBb) = (22)2 = 16

Trihibrid (23)2 = 64

Perkawinan Intermedier

(Dominansi tak sempurna)

Pd Mirabilis jalapa

P mm X MM

putih merah

Mm X Mm

Merah muda ( pink)

MM 1

Mm

Mm 2

mm 1

Perkawinan Kodominan

(dominansi parsial)

Pada sapi Shorthorn

P : RR X rr

Merah putih

Rr X Rr

Coklat

RR 1

Rr

Rr 2

rr 1

Implementasinya pada ternak: Jika jumlah gamet (gen)

sama dengan jumlah kromosom

Maka Kombinasinya*

Sapi 2 n = 2 30 kombinasi gamet = 1.07 x 10 9

Kuda 2 n = 2 32 kombinasi gamet = 4.29 x 10 9

Manusia 2 n = 2 23 kombinasi gamet = 8.3 x 10 6

So, What is the conclussion: -

Note : More than a 100 or 1000 gens/ Chromosome

S u m m a r y• Gregor Mendel is considered the father of genetics

• The amount of difference between parents and offspring is caused by genetics and the environment P= G+ E

• Fertilization occurs when the sperm cell penetrates the egg and the chromosome pairs are formed again when fertilization takes place

• Genes control an animals traits

• Some genes are dominant and some are recessive

• Animals may carry two dominant or two recessive genes for a trait. They are called homozygous pairs

• Animals may also carry a dominant and recessive gene pair. They are called heterozygous pairs

• Livestock improvement is the result of using the principles of genetics