Red Jackdaw

"Multicellularity has evolved independently dozens of times in the history of Earth, for example in plants and animals"

Wikipedia - http://en.wikipedia.org/wiki/Multicellular_organis...

Are there any recent examples of this?

In the taxonomic rank, there are ranks like order, family, genus, species...

Roughly how many different genera (plural of genus) of animals are there? I can't seem to find this anywhere on the interent :(

I was wondering, If I wanted to say 'I lived with my friends for one week'

Would I say:

1. Ich bin fur eine Woche mit Freunden geblieben.

or

2. Ich habe fur eine Woche mit Freunden gewohnt.

Which one makes more sense if you were to bring it up in an account of a holiday? Thanks :)

"A snail is at one corner of the top face of a cube with side length 1 m. The snail can crawl at a

speed of 1 m per hour. What proportion of the cube’s surface is made up of points which the

snail could reach within one hour?"

Now I've got the answer to be pi/4 by:

(pi * 2)/4 = 0.5pi.

0.5pi * 3 = 1.5pi.

1.5pi/6 = pi/4.

But the mark scheme says the following:

In one hour, the snail can reach points within 1 m of the corner

at which it starts. So it can reach some of the points on the

three faces which meet at that corner, but none of the points on

the other three faces. On each of the three reachable faces, the

points which the snail can reach form a quarter of a circle of

radius 1 m.

So the required fraction is:

3 * 1/4pi * 1 * 1

_____________ = pi/8

6 * 1 * 1

Where have I gone wrong/is the mark scheme wrong?

Is it better to wear 3 layers of thinner clothing, or 1 layer of heavy and thick clothing? Is there an explaination as well? Thanks.

In a battery, potential difference moves electrons from the positive terminal to the negative one. But what causes this potential difference?

Are there more electrons on one side of the battery? Also, why don't the chemicals in a battery react when the two terminals aren't linked together by a conductor? Why do they suddenly start an electron flow only when the two terminals are attached, surely they react anyways?

Its probably one of the basic circle theorems which I have failed to spot, but I have spent ages on this question, and I would just like some help, explaining how you arrive at the answer, and what the answer is for this question:

http://i52.tinypic.com/14siq1v.jpg

Well, my physics teacher was talking about speed units. I understand it can be written as m/s, but my physics teacher also showed us that it could be written as m speed^-1. For example:

300m/1 second = 300m/s or 300m second^-1.

He did talk about x/x and powers, but could someone please explain to me how you get from:

300m/1 second

to

300m second^-1.

in terms of algebraic examples or wording?

I heard my friend use this ringtone, and I love the the lyrics and melody...Unfortunatley, I dont understand a word of it, as it is in mandarin or cantonese, but I would like to find the full length of this piece + the artists. Any ideas what this short piece is?

If this isn't possible, could a fluent speaker give me the pinyin so I could search it on google?

http://www.zedge.net/ringtones/450114/chinese-ring...

As a child, I had always assumed that the cold air around me gave me colds. However, as I grew up, I learnt about bacteria and viruses etc, causing common colds and other illnesses.

Despite this, I still wear a coat to keep warm when its chilly, to avoid catching colds.

So whats the link between temperature and the cold virus? Is there one?