The condition where a pteridophyte produces two kinds of spores and sporangia is termed as

Give scientific reasons: In pteridophytes,the development of the zygote inside the female gametophyte is considered an important phase.

In $Selaginella$,the embryo develops into:

Heterosporous condition and ligulate leaves are found in

The seed habit was first established in .........

In which group of the following would you place the plants having vascular tissue and lacking seeds?