Alternation of generations, also called metagenesis or heterogenesis, in biology, the alternation of a sexual phase and an asexual phase in the life cycle of an organism. The two phases, or generations, are often morphologically, and sometimes chromosomally, distinct. The life cycle of the fern.

In nonvascular plants, the gametophyte generation is dominant. The tiny sporophyte grows on the gametophyte plant. In vascular plants, the sporophyte generation is dominant. In seedless vascular plants such as ferns, the sporophyte releases spores from the undersides of leaves.

The life cycle of the fern has two different stages; sporophyte, which releases spores, and gametophyte, which releases gametes. Gametophyte plants are haploid, sporophyte plants diploid. This type of life cycle is called alternation of generations.

The life cycle of both the plants are same, that means both types of plants go through the alternation of generations, but in vascular plants dominating phase is sporophyte, which is diploid and in non-vascular plants dominating generation is gametophyte, and second is sporophyte.

Vascular vs Nonvascular Plants The main difference between vascular and nonvascular plants is that a vascular plant has vascular vessels to carry water and food to all the different parts of the plant. Instead, a nonvascular plant has rhizoids, small hairs that keep the plant in place.

Organs & organ systems of the plant body The vascular plant sporophyte (hereafter, simply called the plant) includes three basic categories of non-reproductive, or vegetative, organs. These are the roots, stems, and leaves.

The difference between seed plants and seedless plants is that seedless plants do not bear seeds for propagation, whereas seed plants bear seeds for multiplication. The plant kingdom is traditionally divided into four main divisions, i.e Thallophyta, Bryophyta, Pteridophyta and Spermatophyta.

The components of the plant vascular system. Vascular system, in plants, assemblage of conducting tissues and associated supportive fibres. Xylem tissue transports water and dissolved minerals to the leaves, and phloem tissue conducts food from the leaves to all parts of the plant.

The ferns, gymnosperms, and flowering plants are all vascular plants. Because they possess vascular tissues, these plants have true stems, leaves, and roots.

bryophytes

Ferns, like all tracheophytes, have vascular systems to bring water up to their leaves. fern, (class Polypodiopsida), class of nonflowering vascular plants that possess true roots, stems, and complex leaves and that reproduce by spores.

Ferns are seedless, vascular plants. They contain two types of vascular tissue that are needed to move substances throughout the plant. With the addition of vascular tissue, water, nutrients and food could now be transported throughout a taller plant.

gametophyte stage

Ferns cannot produce secondary tissues and therefore modify their primary tissues. Their findings indicate that the fern’s apparantly collenchymatous tissue is in fact made of sclerenchyma cells that mimic the properties of collenchyma, and have the potential to increase in hardness through sclerification.

The veins of fern leaf involve furcate venation of arrangement, i.e. veins are arranged in a fork-like manner. If the branched veins do not join each other towards the leaflet margin then it is known as open furcate venation.