Pollen grains are released from
Macrosporangium
Microsporangium
Megaspore mother cell
Archegonium
Identify $'a'$ in given figure :
The cell that divides to form two male nuclei in angiosperms is
Identify labelled part $'X'$ from the figure :
Microsporangia develops in to
Describe internal structure of anther by mentioning about typical stamen.