Do I have a penis?

This morning:

Me..walking past Jonas's room to get his clothes together for the day.

"Mommy!"
"Yes dear..good morning"
"Good Morning Mommy!"
"Come lay down with me Mommy!"
"Ok"

So I go in and snuggle up with him. Ok, first I asked him if he was wet and passed my hand over the sheet...then I got in bed.
We lay there quietly, enjoying the snuggly quiet of the morning. After a few moments...

"Mommy?"
"Yes, son"
"Do I have a penis?"
"Yes, you do have a penis"
"Does daddy have a penis"
"Yes, daddy has a penis"

a pause

"Does Miss Elisha have a penis?"

Ok. here's where it gets funny to be me. Cause I am all... Miss Elisha PROBABLY doesn't have a penis. But if she did that would be ok. (Miss Elisha is his daycare teacher and a hot little blonde number). Now really if she has a penis that would be her private business, so should we really be discussing this anyway? So I ponder if I should say, boys have penises and girls have vagina's? Well, what about those people who have the wrong parts...you know, transgendered folks. Its hard work being me and being so open an accepting. I don't want to give him the impression that it would be wrong for Miss Elisha to have a penis... or to automatically ASSUME she has a vagina.

"I don't think Miss Elisha has a penis honey, maybe you should ask her today at school".