Reproductive science

Jordan has had a lot of science questions about reproduction lately.

J: What happens when a robin has puberty with a blue jay?
R: Um.  Can you tell me what you mean by puberty?
J: Like when a robin is the mom and a blue jay is the dad.
R: Oh, that's called mating.  Actually, different animals don't mate.  First of all they don't want to, and second of all if they did, nothing would happen.
J: Nothing?
R: Nothing.
J: You wouldn't get partly blue jay and partly robin?
R: If the animals are only a little bit different, then the mating could work and you could get a mix of the parents.  Like with different kinds of dogs.
J: But could science do it?  Like, instead of mating, could you do it with chemicals?
R: Actually Daddy does that at work.  You remember how the genes are the information in your body that tells your body how to grow?  Daddy takes genes from one thing and puts them in another thing, and that mixes them a little bit.  He especially likes to take genes from a jellyfish that glows in the dark and put them into his zebrafish, so then his zebrafish glow in the dark.
J: That is SO COOL.

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J: Do plants mate?
R: Some of them do, yes.  It depends on the plant.  You know how flowers have different parts?  There are girl parts and boy parts in a flower.  The pollen is the boy part, and the, um. the other part that the pollen sticks to, that's kind of like the girl part.
[This is already more botany than I had at the tip of my tongue, and was starting to make me wonder what I mean by "boy parts" and "girl parts" for plants.]
J: What about grass?
R: I'm pretty sure grass is different than flowers.  I think maybe it just makes seeds, but without mating?  I don't really remember.  This is a really good question.
[The conversation changed, and I texted Dale.]
R:  Jordan wants to know if plants mate.  I said angiosperms, basically - not all plants.  Is that right?
D: Actually they pretty much all do.  Some ferns have mobile sperm that swim.  No joke.

*    *    *

J: Do crabs lay eggs?

R: Yes, they do.

J: I would not think they would do that because I don't see that they have any private parts.

R: Actually they do have private parts.  Get this:  They keep them on the inside.

J [laughing]: Whaaat!

R: Yep.  A lot of animals do that.  They keep them inside, and just bring them out when they need them.  Then when they're done they slide them back in.

J: [laughing hysterically]

R: It's a very good system because they're protected in there.  

J: Wow.  I did not know about that at all.