Question

8. The spike is
(a) Collection of sporangia
(b) Collection of spores
(c) Tip of a dichotomous branch
(d) Collection of sessile sporophylls​

Answer 1

Answer:

Structure of Ophioglossum:

Sporophyte:

The sporophyte is differentiated into a sub­terranean rhizome with roots and spirally arranged leaves bearing sporangiferous spike.

ADVERTISEMENTS:

Stem:

The stem is represented by a short, erect, subterranean rhizome. But in epiphytic species, it is horizontal and dorsiventral structure. The upper surface of the rhizome produces numerous leaves in an irregular spiral. The rhizome is anchored to the soil by numerous fairly stout adventitious roots growing from the under- surface of rhizome .

A T.S. of the rhizome is somewhat irregular in outline due to the presence of persistent leaf bases and roots . Internally, it is differentiated into an outer epidermis, middle cortex and inner stele. The outermost layer is epidermis which is single layered, suberised and devoid of any stomata.

The cortex is composed of undifferentiated (homogenous) thin-walled parenchymatous cells and is characterised by the absence of sclerenchyma.

Answer 2

Answer:

nice dp

Explanation:

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