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Tuesday, March 30, 2010

MUTATION ?


Today I learned about Mutation from my Science teacher. Mutation is an interesting science subject indeed.

What is a Mutation ?


1. A mutation is a spontaneous change in a gene or chromosomes, resulting in changes to the characteristic features (phenotype) of the organism.

2. An organism which has genes or chromosomes undergone mutation is called a mutant.

3. Mutations can occur in any cell at anytime, but fortunately mutations seldom happen.

4. Mutations which happen to gametes can cause :

- deformity in the foetus

- damage to the brain

- diseases such as Haemophilia and Down's syndrome.

5. A mutant gene or chromosome can be passed on to future generations.



By Sasbadi Nexus Vista SPM Form 4.5 Science.



Mutation = 突變
Gene = 基因
Chromosomes = 染色體
Deformity in the foetus = 胎兒畸形
Damage to the brain = 大腦損害
Haemophilia = 血友病
Down's syndrome = 唐氏綜合徵


http://ghr.nlm.nih.gov/handbook/illustrations/xlinkrecessivemother

突變在生物學上的含義,是指細胞中的遺傳基因發生的改變。它包括單個鹼基改變所引起的點突變,或多個鹼基的缺失、重複和插入。原因可以是細胞分裂時遺傳基因的複製發生錯誤、或受化學物質、輻射或病毒的影響。
突變通常會導致細胞運作不正常或死亡,甚至可以在較高等生物中引發癌症。但同時,突變也被視為物種進化的「推動力」:不理想的突變會經天擇過程被淘汰,而對物種有利的突變則會被累積下去。中性的突變對物種沒有影響而逐漸累積,會導致間斷平衡。


http://zh.wikipedia.org/zh-hk/%E7%AA%81%E5%8F%98

.....吸煙者平均每吸15支煙,DNA發生1次突變,其中的部分突變會造成基因永久性損傷,甚至患上癌症並可代代相傳.....

http://big5.gov.cn/gate/big5/www.gov.cn/fwxx/kp/2010-03/01/content_1544409.htm

http://mag.epochtimes.com/b5/147/7131.htm

Wednesday, March 24, 2010

Welcome to my blog

Greetings everyone,

Sorry that my blog has been idle for a long time. After subscribing to Streamyx Internet, I will now be able to relaunch my blog and spend more time on it with new contents.

Hope you all enjoy!

Monday, March 22, 2010

Streamyx

Streamyz is now installed to our home telephone line on 22-3-2010. Telecom's streamyx contractor came at 6:00pm

We can access the internet now.