Hi Team!

Sharing your data with others is a really important part of the scientific process, so I hope you all enjoy making your slideshow!  To answer your questions:

Most plants don't need soil to germinate, since they get almost everything they need from their food stores and the water they absorb.  However, once a plant has germinated and it starts photosynthesizing, the plant will need lots of nutrients.  Usually, plants get these nutrients from the soil - things like nitrogen and phosphorus - so most plants need soil when they're a little bigger.  There are some weird plants that don't need soil at all, though.  For example, epiphytes are plants that grow on other plants instead of growing in the soil.  A lot of orchids are epiphytes; they grow on trees, and their roots grab the tree bark instead of digging into soil.

For your second question, Minna had a hypothesis early on that the seeds in the dark were germinating first because normally seeds are buried in soil where it's dark until they've grown enough to reach light.  That seems like a pretty good hypothesis to me!  I think many seeds probably do germinate better when it's dark, since a seed that germinates when it's not in the soil will have a hard time getting nutrients and water.  However, as you all know, plants do need light for photosynthesis.  At first, newly germinated plants can use up the food that was stored in their seed, but eventually that will run out and they will need light instead.  So I don't know how long your dark plants will last!  I noticed in your picture that the seeds are getting at least a little light, even if it's only when you're checking them each day.  That might be enough to keep your seedlings alive for a little while, but I doubt it will be enough for long.  One thing that plants do when they don't have enough light is grow really long and skinny.  They do this to try to reach farther and hopefully reach some light.  It's called etiolation.  Do you think your little plants growing in the dark are doing this - growing long and thin with really tiny leaves so they can try to find some light?  I does sound like they're growing fast!

Good luck with your slide show!  Let me know if you have other questions.

Hi Bernie - do you remember the parts of a seed?  There's the embryo, the endosperm (which is the food for the embryo), and the seed coat.  The embryo is what is growing into a plant now.  When it grows, it uses up ("eats") all of the endosperm for energy, so that's gone.  All that's left of the seed now is the seed coat.  Plants eventually grow leaves and push the seed coat off, so it's lost - it's not needed any more!  It looks like one of your seedlings (the one you're talking about) has done this, and the others will probably do the same thing soon.