2007-06-13 05:15:33 · 6 answers · asked by FENIL P 1 in Science & Mathematics ➔ Biology
two
2007-06-13 06:01:16 · answer #1 · answered by g2hn 3 · 0⤊ 0⤋
Simple answer: 2
Interesting answer: 2 1/2 (Two real eyes, and the evolutionary remains of a third)
The pineal gland in the brain is derived from the same tissue that gives rise to the retinas, and its cells resemble the cells that are in the retina. It also helps control the body's sleep/wake cycle.
In fossils and some "primitive" animals (like tuataras and lampreys), it is much more developed. There is an opening in the skull, and it is close to the surface of the head, where it is covered by a thin scale. While it can't really see like a normal eye, it can detect light and darkness, and may help tell the reptile whether it is night or day.
In mammals, it no longer has this function. Since it is buried deep in the skull, and no longer senses light, evolution has phased out this ability.
2007-06-13 10:20:52 · answer #2 · answered by andymanec 7 · 0⤊ 0⤋
You have 2 eyes, 1 pair of eyes
2007-06-13 05:20:36 · answer #3 · answered by Tsumego 5 · 1⤊ 0⤋
Are you serious?
Well, it depends - are you considering every little bug and parasite that may be in or on you? Some of those can have eyes. I assume you consider a fetus a body of its own and don't count those.
2007-06-13 05:20:31 · answer #4 · answered by ? 5 · 1⤊ 0⤋
Just a pair of eyes.
In case of any doubt, jus catch a glimpse of your face upon a mirror!
2007-06-13 05:28:59 · answer #5 · answered by Vytheeshwaran V 4 · 0⤊ 0⤋
there are no "i"s in "human body" there are only 3 vowels u,a and o but no "i"s. A silly question gets a silly answer
2007-06-13 05:23:33 · answer #6 · answered by Jerrry H 3 · 0⤊ 1⤋