For cryopreservation, plant materials are frozen at
$-196^{\circ} C$
$-150{ }^{\circ} C$
$-80^{\circ} C$
$-40^{\circ} C$
Pollens are be stored at which temperature
Flower is intersexual in
A typical angiosperm embryo sac at maturity, is
Entry of pollen tube with two male gametes and tube nucleus through micropyle, is
One celled suspensor is found in