Can you define "kinds" for me?
No, I don't think I can. We can take the modern scientific definition of the word kind, but that doesn't mean that's how the author of Genesis was using it. We could look up the Hebrew for the word kind, and maybe get some insight, but if that doesn't work, I don't think there's a way we could really know what the author meant by the word kind unless we were there ourselves.
What we can do is talk about the dimensions of the ark and how much space there was for the animal. Given the dimmensions in the Bible, the experts have estimated there was space for 16,000 animals on the ark. I also read some excerpts from a book all about Noah's ark being plausable, which discusses every question you could think of. The had some numbers for how many animals they had, and specifically how many reptiles, how many birds, and how many mammals. I'll see if I can find that book again if you're interested.
Ok. How did the penguins and polar bears get from their natural habits to the ark.. And back again?
Well, the animals got there because God sent them there. As for how they got back after the flood, I'm really not sure about the penguins and polar bears. In the book I was referencing above, it talked about the animals that got to north/south America and Astralia after the flood. To give a brief answer, the animals could have been taken there when people went there. The penguins and polar bears does seem like a more interesting question, and one I'd like to investigate more (and here I was thinking I had answered all of my Noah's ark questions already). While it's true those animals wouldn't last long in the climate of the middle east, I would hypothesize that immediately after the flood, the climate was no where near back to normal yet, giving the animals ample time to migrate themselves back to their normal habitats, but that's just a guess at this point. I wonder if that book I've been refernsing discusses that?