Why is our blood red?

Question

why is blood among mammals naturally red?

why has nature and evolution choosed red as the colour of our blood?

What benefits does this have in having red as the colour of our blood?

Is it too stand out?

Why not yellow, blue or green?

Answer 1

The haem group in the haemoglobin that carries oxygen around the body (in red blood cells) is what gives the red blood cells (and therefore blood) the red colour.

Answer 2

i heard it's a bit blue and when it comes out of your body it turns instantly red because it comes in contact with oxygen, something like that.

EDIT

errr forget what i just said... look: http://www.globalclassroom.org/blublud.h...

Answer 3

colours are the absorption (and reflection ) of frequencies of light. The composition of material determines the frequencies that are reflected to create colours. There are frequencies that we cant see!

I guess the fact that red blood carries oxygen has something to do with it (blood is blue before it carries oxygen ie your veins are blue).

Answer 4

It is simply the consequence of having an abundance of heamoglobin (inside countless millions of red blood cells) which contains iron ions that as it happens absorb all colours except red which they emmit hence the colour of blood. Had copper ions been there instead of iron ions our blood colour would have been blue.

As it happens blood which is also a symbol of life energy has the colour of fire. Life energy is thought by some to be some kind of fire. The red colour is a common denominator between the two.

Answer 5

blood is red because of the presence of hemoglobin and red cell's nature took the red color because red is easily identified from a long distence if a mamel or a living form is in denger the others can get alert from a few distence to see the red colour that their is some problem over their, with the same concept red is used to in trafic, or showing the mark of denger, it's a different issue that love is also the colour of red !!!!!!!!!!!!!!!!!!!

Answer 6

the red blood cells make it red

Answer 7

. .it's because of the hemoglobin. . .

Answer 8

It's caused by the iron in our haemoglobin. In comparison, some smaller animals have blue/green blood because they have copper in their blood cells rather than iron.

Answer 9

im not sure, why its red. But listen to this, PLEASE LISTEN! No matter what anyone tells you, Our blood is not blue.

IT never is.

People will tell you, that blood is blue untill it hits oxygen (air).

Scientist have prooved that your blood isn't blue. Its always red. Always.

Also , the question your asking has no reason. You'd be asking the same question if it was green, yellow, blue. It just is that colour. Think about it. If it was green, you would ask "Why is it that green, what benifets from being green and is it to make it stand out. Why cant it be red, yellow or blue"

Answer 10

Hemoglobin content of the red blood cells make the blood pigmented as red. Hemoglobin is made up of iron which causes the erythematous (red) pigmentation.

Answer 11

BECAUSE OF HEMOGLOBIN  

Answer 12

If it was green, we would be Vulcans.

Answer 13

evolition is not based on benefits, only slightly... if you mutate in a way that helps you have more chances of survival, however some evolutionary traits are just random and don't help or change anything.

i imagine its color is to do with the fact that's its full or red blood cells, the pigmentation for this is probably due to a commune ground all mammals share, like the air we breath and oxygen, not too sure.

Answer 14

does that even make sence? "evolution dose'nt usually make benifits"!

Then how do we have all this benificiall life? even over BILLIONS of year...I mean...COME ON!!!!  

Answer 15

due to the presence of hemoglobin in it.