Mini tomato plant?

[cloz]

I started some tomato seeds that I had saved last fall from 2 tomatoes off the same plant. They were started about mid January using the coffee filter method. I transplanted the germinated seeds to this 6 pack and they have been growing under flourescents until about a week ago. All is well with 3 of them but one plant is noticeably smaller and a different color than the other 3. Any idea what could cause the difference? Just a weak plant? The little one seems to be growing just fine , although very slowly compared to the others. The variety is Red Cherry Large (I am guessing the Ferry Morse seeds). I purchased the plants last year at a garden center. I will try to upload a picture.
I may not plant these because I have more than I need started in the trays in the second picture. I will have plenty to give away to friends and relatives as I will be planting about 60 plants.
I am just curious as to the difference in growth since I know the seeds came from the same plant.

[dice]

It looks nitrogen deficient, but assuming that all were treated
the same way as far as light, planting mix, fertilizer, etc,
it could be a genetic difference in that one plant.

[bullish]

Wow - that is a big difference!

[cloz]

Originally Posted by dice

It looks nitrogen deficient, but assuming that all were treated
the same way as far as light, planting mix, fertilizer, etc,
it could be a genetic difference in that one plant.

All the plants have been treated exactly the same. Same watering, same lighting, same seed staring mix and the tomatoes from which the seed came were picked from the same plant. The "runt" has always had the odd color and been much smaller than the others. Now I am curious. I may have to grow it to see what it turns into. The only reason I started these was to use them to test my improvised heating system (a 12' rope light underneath four 12" ceramic tiles).