Gymnosperms (AIPVT)

The gymnosperms and angiosperms together compose the spermatophytes or seed plants.

Conifers form the largest group of living gymnosperms. Conifers have a total of 65-70 genera and 600-630 species.

Non-motile spores are formed in conifers.

The pollen grains mature inside the ovule and produce sperm cells.

Vessel elements are present in Gnetophytes. The vessels in the wood of gnetopsids are derived from tracheids with circular bordered bits, in contrast to the vessels of angiosperms, which are derived from scalariform tracheids.

Nageia in Podocarpaceae have broad, flat strap-shaped leaves.

Bennettitales are fossil gymnosperms.

The gymnosperms originated in the late Carboniferous period. This appears to have been the result of a whole genome duplication event around 319 million years ago.

A grain of pine pollen also has two large air sacs to make it buoyant in the wind and these give the pollen a Mickey Mouse hat appearance.

Ovaries are absent in gymnosperms and thus, the seeds are naked.

The Pinaceae are always monoecious and include the common pines, firs, larches and spruces.

Arils are found in yews and related conifers. Aril is a specialised outgrowth from seed that partially or completely covers the seed.

In cycads and ginkgo, the cotyledons remain within the seed and serve to digest the food in the female gametophyte and absorb it into a developing embryo.

The term microsporophyll is used in gymnosperms to denote male cones.

The pollination in gymnosperms is brought about by wind.

The reduction division takes place in Megasporangium, which divides to form 4 megaspores.

The seed coat, in case of gymnosperms, is derived from female sporophyte.

All conifers yield softwood.

Pinophytes, also called conifers, are also the tallest and most massive living organisms; coast redwoods (Sequoia sempervirens) can exceed 100 metres (328 feet) in height and the giant sequoia (Sequoiadendron giganteum) can have a girth of 31 metres (101.5 feet) in circumference.

This is the correct match. Pine seeds have thin winglike structures, cycads have brightly coloured sarcotesta, ginkgo seeds have foul-smelling sarcotesta and juniper has fleshy cones, which are eaten by birds.