In a typical angiosperm, what is the sequence of structures encountered by the tip of a growing pollen tube on its way to the egg?
1. micropyle
2. style
3. ovary
4. stigma
A) 4 ? 2 ? 3 ? 1
B) 4 ? 3 ? 2 ? 1
C) 1 ? 4 ? 2 ? 3
D) 1 ? 3 ? 4 ? 2
E) 3 ? 2 ? 4 ? 1
Answer: a