Feature
Tanjina Haque Toma
If two or more infants are born in a single pregnancy then it is called twinning. There are two types of twins -
1. Dizygotic twins
2. Monozygotic twins
Approximately 2/3 of twins are dizygotic or "fraternal" and their incidence of 7-11 per 1000 births increases with maternal age. They result from simultaneous shedding of two zygotes that have totally different genetic constitutions; the twins have no more resemblance than any other brothers and sisters. They may or may not be of different sex. Usually the zygotes implant individually and develop it's own placenta. Sometimes, the two placentas are so close to each other that they fuse.
The monozygotic twins develop from a single fertilized ovum; also called "identical twins". The rate for monozygotic twins is 3-4 per 1000 births. They result from splitting of the zygote at various stages of development. The earliest separation is believed to occur at the two-cell stage; in which case two separate zygotes develop. Implantation occurs separately and each embryo has its own placenta. Dizygotic twins can be recognized as partners of a monozygotic pair by their strong resemblance in blood groups, fingerprints, sex and external appearance such as eye and hair colour. Splitting zygote usually occurs at early blastocyst stage. Inner cell mass splits into two separate groups of cells within same blastocyst cavity.
Although, triplets are rare (about 1/7600 pregnancy), birth of quadruplets, quintuplets and so forth is rarer. In recent years multiple births have occurred more frequently in mothers given fertility drugs (gonadotropins) for ovulate failure.
2nd Year
Ibrahim Medical College
[ Reference: Langman's Medical Embryology]
The power of youth and the power of the Internet
Asrarul Chowdhury
The cover story, "Online social networking" in the Star Campus (21 Oct 2007) is a timely issue featuring the ever-growing online social network community. The three pieces by Mahdin Mahboob, Sarah ZH, and Binoy Barman introduce readers to this recent phenomenon. Unfortunately, in none of the three pieces there's any reference to groups and causes related to Bangladesh.
Bangladeshis are slowly and gradually making their presence felt in these networks. I'm not a 'net generation' as Barman terms the youth. I don't see anything wrong with the youth in experimenting with the Internet. After meeting this wonderful 'net generation' recently, I can only see and envy the vast potential the 'net generation' has in letting the world know the good things of Bangladesh.
Department of Economics
Jahangirnagar University
asrarul@gmail.com
Oscar Wilde Quotes
* A cynic is a man who knows the price of everything but the value of nothing.
* A dreamer is one who can only find his way by moonlight, and his punishment is that he sees the dawn before the rest of the world.
* A gentleman is one who never hurts anyone's feelings unintentionally.
Answers (Test your IQ)
1 A: In 72 hours it would be midnight again, so it could not be bright and sunny.
2 A: In a roll of toilet paper.
3 A: GENERATION
1234 carries heredity - gene
456 - is a period of time - era
567- is a pest - rat
890 is a charged particle ion
4 A: Stop imagining!
5 A: Ambulances do not put out fires.
6 A: The cobbler and his wife gave each of his nine children a pair of shoes. That left one pair in the box. They then gave this tenth child the box with the shoes in it.
7 A: An envelope!
8 A: Ass ass i nation
Assassination
(Compiled by Amanat Ahmed)
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