Question

The exceptional character of fern leaf tips are
A. Circumnutation
B. Nutation
C. Circinate ptyxis
D. All of the above

Answer 1

Fern leaves are called megaphylls. The leaf tip of fern remains curled. Fern stems, also called rhizomes, are said to be inconspicuous because they grow below the surface of the substrate in which the fern grows.

Complete answer:
Ferns have complex leaves called megaphylls, which are more difficult than clubmoss microphylls. A trophophyll and a sporophyll are split into two kinds of leaves. A trophophyll frond is a vegetative leaf similar to the usual green leaves of seed plants that, instead of producing spores, only photosynthesis produces sugars. A sporophyte frond is a fertile leaf that develops spores that are typically clustered in sporangia to form sori. In its developmental stages, ptyxis is the way a leaf is folded. Circinate vernation, known as fronds in fiddleheads of ferns, is a coiled arrangement of leaves. They are tightly curled when fronds are developed in ferns so that the tips of young leaves are covered within the coil. Ferns are vascular plants. Ferns first appeared in the fossil record about 360 million years ago in the middle Devonian period, but many of the current families and species did not appear until roughly 145 million years ago in the early Cretaceous period.

So, the correct answer is option C.

Note: A fern is a member of a group of vascular plants which have neither seeds nor flowers and reproduce through spores. As these are vascular plants, they have specialised tissues to conduct water and nutrients. They have life cycles in which the dominant phase is the sporophyte, this is how they differ from mosses.