POST KHAS UNTUK ATIQAH RAZAK

yer Atiqah Razak~~
Selamat Datang yer~~


duk umah mkn tdo mkn mkn da chubby mcm ni ke erk??

jeng jeng jeng.....

HAHAHAks

GENETIC INHERITANCE : Cross That Deviate From Mendelian Inheritance

Baiklah marilah kita teruskan dengan beberapa lagi cross yang tersisih daripada Mendelian Inheritance, mean larilah dan xmematuhi pun mononybrid ke dihybrid ke atau law of segregation and law of independent assortment..ini sudah lain yer..
baiklah kita ada Codominant Alleles, Incomplete Dominant Alleles, Multiple alles, Polygenes dan Lethal Alleles and Link Genes.

Sengaja buat yang besar dan yang kecil. Yang besar tu maksudnya selalu menjadi tajuk untuk keluar exam dan yang kecil tu kureng~ dan kita belajar pun sikit je, so just go to the definition~~

Codominant Alleles

2 alleles are codominant when both alleles are fully expressed in heterozygous form.

(contohnya mcm ABO Blood Group)

Genotypic and phenotypic ratio = 1:2:1

Incomplete Dominant Allele

Maksudnya "one allele is not fully dominant over its partner, so in heterozygous condition, total product is intermediate between that of dominant and recessive alleles".

So genotypic and phenotypic ratios = 1:2:1

Multiple Alleles

"One gene having more than two alleles OR all alleles control the same character"

contohnya macam ABO blood tyepe in human.

ada 3 different alelles: IA , IB  &  I .

BLOOD A boleh jadi : IAIA @  II

  BLOOD B: IBIB @ IBI

BLOOD AB : IAIB

BLOOD O : II

Polygenes

Poly = banyak

so mean polygenic inheritance, a characteristics is controlled by many genes.

~cukup~

Lethal Alleles

•Lethal alleles is a allele that may cause death

•

•2 types: - dominant lethal gene (cause death even in heterozygous condition)

               - recessive lethal gene (cause death only in homozygous condition)

~diagram nanti yer~

GENETIC INHERITANCE: Dihybrid

Helo~~ Hai..
oleh kerana mata ini masih belum mengantuk (2.02 a.m., 20 Jan 2010 opps 2011),  
maka diteruskan pula dengan DIHYBRID...

"The inheritance of 2 characterics, each one controlled by a different gene at different locus"

(haa~~yg ini lawan kpd mono td...sbb ia ada 2 characteristics misalnya Tinggi dan warna and controlled by diff. gene la..Tinggi: TT @ Tt @ tt then warna PP@Pp@pp..

tp dua ciri ini digabungkan terus laa~~

Mendel's Second Law = "Law of Independent Assortment"

: " Each allele of one gene is assorted independently with any allele of another gene during meiosis

ATAU LAGI SIMPLE

: Allele located on different chorosome assort independently during meiosis"

So phenotype ratio utk dihybrid ialah; 9:3:3:1

GENETIC INHERITANCE : Monohybrid

Sebelum mendalam lg jom fahami apa itu
True Breeding: Organism that are homozygous for any given genotype and therefore pass it on to all their progeny in a cross with a similar homozygote.
(xpaham?? haha~maksudnya xksah la monohybrid ke dihybrid ke syarat kacut dia mesti dua2 tu homozygous~~mksudnya boleh jadi TT X tt @ TT X TT @ tt @ tt...err gitu la..kalo Tt X tt xnak la sbb Tt tu da hetero~~faham yer adek2? hehe)

Now kita pergi kepada Mendel's Experiment

Agak2 kan kenapa beliau memilih Garden Peas (Pisum sativum) ??

1) Easy to grow

2) Had short life cycle

3) Pollination could be controlled

4) Easily observable characteristics.

Now letds go to MONOHYBRID (eah excited plak)

Ok~ This one just "involve a single characteristics determined by one gene".. maksudnya pada satu2 masa ia cuma kaji satu faktor jer.. Contohnya ketinggian atau warna atau lokasi bunga~~

MENDEL's FIRST LAW = "LAW OF SEGREGATION"

"Each hereditary characteristics is controlled br two alles and segregate then pass into separate gamete"

~wink3..maksudnya contohnya hereditary characteristics lets say kita amik Height kan..ia dicontrol oleh dua allele iaitu sama ada TT @ Tt @ tt then bila cross masing2 akan berpisah kepada gamete lain kan.. Kalo TT jd T, T kalo Tt jd T , t

so paham yer~~

So phenotype ratio utk monohybrid ialah; 3:1

GENETIC INHERITANCE : Type of Cross

Baiklah sekarang mari memahami bahawa type of cross ada empat iaitu Test Cross(popular), Back Cross, Self Cross dan Reciprocal Cross.


Test Cross : cross between a recessive homozygous(tt) with an organis of dominant phenotype but unknown genotype (maksud xtau tu, boleh jadi genotypenya TT@Tt as long it is dominant)

Back Cross : A mating between individuals of the P and F1


Self Cross(sumbang mahram yer disitu) : Cross between male and female from same generation.


Reciprocal Cross: A cross reversing the roles of males and females to confirm the result obtained from an ealier cross. (kalo nak paham yg ini ia juga untuk determine that a particular gene is sen-linked or not. Contohnya yg popular masa kita nak crosskan berkaitan haemopholia tu ataupun color blind).

GENETIC INHERITANCE

Baiklah...Setelah berfikir pendek, akhirnya saya memutuskan utk discuss about Genetic Inheritance... Sebagai Bakal Pensyarah Biologi(aiyyoo mrepek lg) saya akan menyimpulkan secara ringkas bab ini...

Terlebih dahulu mari kita belajar mengenai semua terms dan definisi yang perlu diketahuilah~~

1) Gamete : Mature male or female reproductive cell with a haploid set of chromosomes

2) Genes : Small section of DNA that codes for a particular protein.

3) Alleles : Alternative form of gene that occupy same location in homologous chromosome.

4) Locus : Specific location of genes on a chromosome.

5) Genotype : Genetic constitution of an organism. (e.g : TT @ Tt)

6) Phenotype : The physical appearance of organism. (e.g. Tall/swarft)

7) Dominant allele : Gene that express it phenotype even in presence of recessive genes.(e.g. TT@Tt =tall)

8) Recessive allele : Gene that expresse only when it present in homozygous. (e.g : tt = swarft)

Next Post

Assalamualaikum, salam sejahtera dan salam 1Malaysia~~

Apa khabar semua? Harap2 sihat yerr~~Alhamdulllah..
Sebelum itu bagi Muslim marilah kita bersyukur kepada Allah dan berzikir Subhanallah Alhamdulillah Allahuakhbar. Lailailallah Muhammad Rasulallah. Selawat ke atas junjungan besar Nabi Muhammad S.A.W.


Saya sedang mempertimbangkan untuk post seterusnya sama ada berkaitan my friends ATAU berkaitan haid dan masalahnya~
By the way, Dr akan study dulu beberapa perkara yang bersesuaian dengan silibus matrikulasi untuk informasi sains biologi dan kimia agar anda membaca sambil belajar.

Segala yang baik datang dari Allah S.W.T. dan diletakkan kepada saya sebagai manfaat semua manakala yang buruk juga datang dari Allah S.W.T tetapi disandarkan kepada saya sebagai sempadan da iktibar semua.

Ok...daaa~~

*wink* +___+