Twins actually varies?

well, regarding my previous post, i decide to not research on how r they delivered. but i can tell u tat most multiple births r usually delivered through c-section due to the risks involved(not sure wat they r though) this part of the research is still quite unsuitable for me. but if i hav the chance when im older, i would definitely look more into the topic.

anyway back to business. i m sure we all what twins r. but i nvr thought tat twins r split into a few categories. anyway here's the info i got off the web.

Identical twins are caused by one egg being fertilized by one sperm. Sometime after fertilization, the egg splits into two genetically identical halves. Identical twins are always of the same sex. They share 100% of their genes, and are in reality, natural clones.

Fraternal twins are formed when two eggs are released by the mother, and each egg is fertilized by a different sperm. Fraternal twins can be of the same or opposite sex. They share up to 50% of their genes, and are no more alike or different than any two siblings would be. It is also possible for fraternals to be of different races or parentage, or to be conceived at different times, resulting in a large weight difference at birth.

There is a third type of twinning that scientists are looking into, called polar body twinning, or "half identical" twinning. This occurs when the mother's egg splits before fertilization and then each half is then fertilized by a sperm. This may explain why some fraternal twins (such as the Olsen twins) look as alike as some identicals, but it hasn't been proven that it occurs, or that it would produce viable twins.

Conjoined twins form exactly like identical twins, but at some point during the stage where the single egg splits, the process stops, and the twins develop attached to one another. This occurs in about 1 out every 100,000 to 200,000 live births, but 60% of conjoined twins are either stillborn or lost in utero. Females are conjoined more than males, at a ratio of 3:1, and they are more likely to occur in India or Africa than China and the USA.

amyway, off for more research!

9/7/08

Wednesday

since when can fungi reproduce sexually???

oops...it seems tat i had made a big mistake. so far only very few fungi can reproduce sexually and they are not really considered sexual reproduction and the process is very complicated. so it seems i have to change my question again.....hmm....wat about how are two or more babies formed and how are they delivered? ya i can do tat, just tat maybe the videos i find may be not suitable for minors(and me), so i will try to find videos suitable for all.

now lets go!

p.s. forgot to update last week's research due to sch event, but u can bet on it tat i will work doublely hard on my research for the posts to come...

8/7/08
Tuesday

CHIM CHIM CHIM!!!!!!!!!!!!!!!

Ok, there's still no videos on the cow's digestive system, even the pictures found seems to be only in a samll amount. well, at least i got one naming the four stomachs and got some info of its digestion process though its not very detailed....


As for the digestion process, here are the few steps

1. The cow tears and chews the food briefly then swallows. She'll eat for more than six hours a day.
2. The food passes into stomach #1 to soften. When the food passes into stomach #2, it mixes and softens more into what is called cud.
3. When Ms. Cow feels full, she burps up a small amount of cud to chew it again. She'll chew her cud for eight hours each day.
4. When the cow swallows again, the cud passes into stomachs #3 and #4 where it is digested further and nutrients are absorbed.
5. Digested food passes through her intestines where more nutrients are absorbed. Waste materials exit the cow as manure.

woah, and according to the source, a cow had to chew at a rate of 50 times per minute. In one day, she move her jaw more than 40,000 times!
Tough life it must have....

2/7/08
Wednesday

Listening better than reading...

Firstly, i decided to split the research into one week for each question. So this week, i would be studying on the differences between a cow's digestive system and a human's digestive system.

Of course, the first thing i had to do is to find out more on the human digestive system. Mind u, it is not just covering our primary sch stuffs. anyway i went to wikipedia and OMG! all the words were greek to me, i dont even understand half of wat its saying. then i thought, wat if i go look for a video presentation, maybe it would be easier to understand.....

And it sure was! i enclose this post with that video tat i found on youtube.

Enjoy! ^^

30/6/08
Monday

This is worst than deciding my secondary school!

well, here's with my second entry and i had to make a choice of 2 out of 5 topics to research on. being given 1) Digestion, 2)Transport in Living Things, 3) Sexual Reproduction, 4) Issues on Sex, 5) Ecology and Nutrient Cycles in the Ecosystem, i am totally spoilt for choice! Now, which one should i pick? After thinking about it for a day n a night n a day n a night n a day again, i remembered how curious i was about the system tat keeps life going. thus i narrowed it down to 3 topics: digestion, transport in living things n sexual reproduction. still in the end, i decided to go with digestion and sexual reproduction.
Next, i had to think of something to reseacrh related to these 2 fields. the question on digestion was rather easy to think of. as i was drinking fresh milk at that time, i remembered tat a cow has 4 stomachs, so how will the digestion process be different from a human digestion process? and as for sexual reproduction, i nearly ran out of ideas when i suddenly ask myself: can a fungi reproduce sexually? after confirming that they actually can with my sci teacher, i made up my mind.

Now, i offically declare that my 2 research questions shall be:
1) What are the similarities n differences between a cow digestive system and a human digestive system?
2) How can a fungi reproduce sexually?

Those decisions r certainly harder than chosing my secondary sch.....

26/6/08
Thursday

Lets get on with the journal!

When i first learnt that we had to do biojournals again, I was like "what? not again!" However, when i learnt that not only is there less work this time, but even that we had to write it in a blog form, i totally had no more objections! Writing my biojournal in a blog is way better than the lame old "research and copy down in your exercise book" method. So, lets get on with the journal!

25/6/08
Wednesday