Pairs and pairs

Question

I'm absolutely full of pairs,
And that's why I'm important.
If my owner's used to describe me,
I'd be like just a pair of letters.

With the first pair, I'm from a plant or animal.
With the second pair, you won't see me at all.
With the third pair, you'll hear me instead.
With the fourth pair, I'm out in the open.

What am I?

Hint:

I'm glad that someone (Tom) fell for the red herring of assuming the answer must be an eight-letter word with each of the last four lines referring respectively to its pairs of letters. But that's not the right solution method.

Edit: nearly two years down the line, I'm ashamed to admit that I've actually forgotten my own solution to this. So here's some hints/guesses based on what little I can remember or what I know about my own riddling style:

Line 2 must be just fluff, but line 3 has got to have some very specific (but possibly very obscure) meaning. Line 4 probably refers to a homophone of a pair of letters (e.g. MT ~ empty, that kind of thing).

I'm racking my brains to remember what I meant by the "first pair", "second pair", etc. The only thing I'm coming up with, possibly, is that it might have been somehow intended to relate to numbers, like multiples or powers of two. Maybe the 2nd, 4th, 6th, 8th or 2nd, 4th, 8th, 16th letters of the alphabet???

Answer 1

I'm absolutely full of pairs, And that's why I'm important.

Latin (English) letters, twenty-six pairs which are upper and lower case.

If my owner's used to describe me, I'd be like just a pair of letters.

The word alphabet comes from alpha and beta, the first two letters of the Greek alphabet.

With the first pair, I'm from a plant or animal.

AA, a battery or cells, which are the basic units of plants and animals.

With the second pair, you won't see me at all.

BB, Big Brother is watching you, but no one seems to have ever seen him.

With the third pair, you'll hear me instead.

cc, motor engines are given in cc as cubic centimetres, and these are noisy.

With the fourth pair, I'm out in the open.

DD, due diligence reveals the hidden, and puts matters out in the open.

---

First fo(o)lio attempt:

Shall I compare thee to a summer's day? Thou art more lovely and more

Sonnetry

I'm absolutely full of pairs, And that's why I'm important.

Fourteen lines with rhyme scheme abab cdcd efef gg

If my owner's used to describe me, I'd be like just a pair of letters.

T.T. - Thomas Thorpe, the publisher of Shakespeare's sonnets

With the first pair, I'm from a plant or animal.

so - a type of usually dairy - but maybe from soy milk - product from Japan

With the second pair, you won't see me at all.

nn - $N_2$ as nitrogen gas is invisible

With the third pair, you'll hear me instead.

E.T. - this song was Katy Perry's fifth number one in the U.S. Billboard

With the fourth pair, I'm out in the open.

Ry - a railway, or a Danish town :)

Answer 2

Are you a:

WORD LADDER?

I'm absolutely full of pairs, And that's why I'm important.

A word ladder consists of pairs of words separated by a changed letter.
The 'important' part is fluff, but we know word ladders are important because the puzzling community wouldn't be the same without them.

If my owner's used to describe me, I'd be like just a pair of letters.

You were invented by Lewis Carrol, who called you "Doublets". That is just like "Double T's; TT, a pair of letters.

What follows is an example of an actual word ladder that changes GENE to GOGO:

With the first pair, I'm from a plant or animal.

GENE - found in living things. @Reve's original guess of DNA alludes to this unexpectedly.

With the second pair, you won't see me at all.

gene > GONE - If you are gone, you are not seen.

With the third pair, you'll hear me instead.

gone > GONG - A gong is noted for being a loud, often sudden, noise.

With the fourth pair, I'm out in the open.

gong > GOGO - Gogo is defined as 'unrestrained and provacative dancing' or 'assertively dynamic'; both meaning "very out in the open."

There may be another top or bottom step to the word ladder but I didn't find anything. Or it may be something like WORD... to WOLF, GOLF, golf being 'in the open', but I can only get half of it

What am I?

You are a WORD LADDER!

Answer 3

I'm thinking that the answer is:

your face

With the first pair, I'm from a plant or animal:

could have been ears as in an ear of corn, or ears on an animal; or could have been eyes e.g. eyes of a potato and eyeballs. After completing the next two though, I'm thinking this is the mouth, which is divided down the center and has pairs of teeth. You can have teeth on leaves, and leaves also have tiny pores called stomata (stoma being mouth in greek).

With the second pair, you won't see me at all:

This one is probably eyes, which cannot see your face (without a mirror).

With the third pair, you'll hear me instead:

Which makes this one ears.

With the fourth pair, I'm out in the open:

Lastly would be your nose is in front of your face, and has a pair of nostrils.

Answer 4

I doubt this is the right answer, but maybe you are:

Iron

Rationale:

Each of the four pairs are anagrams of the symbol for iron (Fe) plus the symbol for one other element.

With the first pair, I'm from a plant or animal.

Life = Iron (Fe) and Lithium (Li), because they're both alive.

With the second pair, you won't see me at all.

Face = Iron (Fe) and Actinium (Ac), because you can't see your own face.

With the third pair, you'll hear me instead.

Fete = Iron (Fe) and Tellurium (Te), because you'll for sure hear a party.

With the fourth pair, I'm out in the open.

Defy = Iron (Fe) and Dysprosium (Dy), because to defy is to resist openly and boldy.