Identification: Grapfruit tree?

For a while now I have been thinking of planting a grapefruit tree from seeds I had collected but never got around to planting. Therefore the seeds were quite dry when I planted them so I really didn't expect them to grow. However to my surprise a seed sprouted a few weeks ago, since then I have been trying to identify if it was in fact one of the grapefruit seeds I planted or some mystery seed, but I have yet to find any strong evidence that it is in fact a grapefruit tree. Thus here are some pictures I took of my plant. Let me know what you think. Also are those small white hairs on the upper part of the stem normal? Is it mould?

 

It does not appear to be a grapefruit seedling.

 

Any idea what you think it is? What types of plants have those white hairs?

 

Sorry, no idea what it might be.

 

Might be a Sunflower (Helianthus), whatever it is it's in desperate need of more sun.