Final answer:
The indusium provides a protected microenvironment for sori and sporangium in ferns, and it is true that it helps in spore development. Regarding the life cycle of ferns, the incorrect statement is that sporangia form on the underside of the gametophyte; they actually form on the sporophyte.
Step-by-step explanation:
The statement that an indusium creates a microenvironment for the sori/sporangium under it is true. An indusium is a flap of tissue that covers and protects the young sporangia which are where spores are produced on plants such as ferns. In the case of ferns, sporangia are indeed produced on the underside of leaves in clusters called 'sori', and the indusium helps to create a suitable environment for the development of spores.
Fern Life Cycle Incorrect Statement
In relation to the fern life cycle, the false statement is "d. Sporangia form on the underside of the gametophyte." In the life cycle of ferns, the sporangia form on the underside of the leaves of the sporophyte generation, not the gametophyte. The sporophyte is diploid and produces haploid spores within its sporangia, while the gametophyte generation is haploid and produces gametes for sexual reproduction.