Sentences with word «gymnosperm»

This plant, which can live for more than a millennium, grows in the extreme conditions of the deserts of Namibia and Angola, and, like other gymnosperms, possesses separate male and female cones.

In gymnosperms the two sperm cells transferred from the pollen do not develop seed by double fertilization but instead only one sperm fertilizes the egg while the other is not used.

By reducing fertility of several widespread gymnosperm lineages, pulsed ozone shield weakening could have induced repeated terrestrial biosphere destabilization and food web collapse without exerting a direct «kill» mechanism on land plants or animals.

To do so, the researchers studied a rather original gymnosperm called Welwitschia mirabilis.

The genome of Picea abies, one of the largest ever sequenced, appears May 22 in Nature and is one of several that have been read out recently from trees known as gymnosperms — seed - bearing plants that don't produce flowers.

While most gymnosperms depend on wind pollination, cycads long ago evolved a relationship with beetles.

In comparison with gymnosperms, which possess rather rudimentary male and female cones (like the pine cone), flowering plants present several innovations: the flower contains the male organs (stamens) and the female organs (pistil), surrounded by petals and sepals, while the ovules, instead of being naked, are protected within the pistil.

Flowers initiated the differences between gymnosperms and angiosperms by broadening the scope of evolutionary relationships and niches open to flowering plants, allowing them to eventually dominate terrestrial ecosystems.

If gymnosperms have been around for hundreds of millions of years, why do these chronologies extend only to a little over 10,000 years, which is an upper limit?

Exceptionally old - aged fire scars are found only on long - lived Gymnosperms (Swetnam 1993).

New data force a rethink of the evolution of gymnosperms, the plant group that includes spruces, pines, and other holiday favorites

They discovered evidence of this duplication in other flowering plants, but not in conifers and other gymnosperms, which produce seeds but no flowers and preceded the evolution of flowering plants.

In gymnosperms, wind deposits a pollen grain on an exposed egg cell, and then the pollen tube — growing at the slow rate of 20 micrometers an hour — releases an enzyme that destroys any tissue blocking the sperm's entrance into the egg cell.

It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth with in the motherplant.

Gymnosperms (Gymnospermae) are a group of seed - bearing plants with ovules borne on the edge or blade of an open sporophyll, the sporophylls usually arranged in cone - like structures.

The production of seeds distinguishes the gymnosperms and the angiosperms from other members of the vascular plants.

The fact that a similar gene cascade has been found in flowering plants and their gymnosperm cousins indicates that this is inherited from their common ancestor.

They were directly preceded by a group known as the gymnosperms, whose mode of reproduction is more rudimentary and whose modern - day representatives include conifers.

The list of threatened plants and animals we rely on is weird and varied, including amphibians, bears, gymnosperms (the family of plants that includes pine trees), cone snails, sharks, and horseshoe crabs.

Wolfgang Stuppy writes that this gives fruiting plants tremendous evolutionary advantages over «naked seed» plants, or gymnosperms, like conifers and Ginkgos.

The genetic sequence of the Norway spruce (shown) could shed light on the evolution of the seed - bearing plants called gymnosperms.

The most familiar gymnosperms are conifers, but this cycad is also a gymnosperm, meaning «naked seed plant.»

The Russians say they found partly digested pollen from various Permian seed plants (gymnosperms) in the guts of three different fossil insects, precursors of bark lice, plant hoppers, and stone flies.

There are an estimated 270,000 known species of angiosperms, or flowering plants, but only about 900 species of gymnosperms, which are nonflowering plants such as conifers, cycads, and ginkgoes.

The team found that angiosperms (flowering trees) and gymnosperms (cone trees) were equally likely to die in drought.

Although this study focused on flowering plants, Bailey said the approach will likely work well across other major plant groups (e.g., ferns, gymnosperms).

Found on cliffs, ravines, and bare rocks from Italy to Yemen, Ephedra is a gymnosperm, meaning, like pine trees, it houses its reproductive structures within cones.

* Correction, 2 April, 1:07 p.m.: An earlier version of this article stated that Ephedra was a flowering plant, when, in fact, it is a gymnosperm.

In addition, the adjacent herbarium houses nearly 7 million dried specimens of algae, fungi, ferns, moss, gymnosperm, and flowering plants from around the world.

Gymnosperms are represented by just four divisions: Pinophyta (conifers), Cycadophyta (cycads), Gnetophyta (gnetophytes), and Ginkgophyta (Ginkgo).

A spruce gene map infers ancient plant genome reshuffling and subsequent slow evolution in the gymnosperm lineage leading to extant conifers.

The results are broken down into five broad groups of plants: monocots, including palms, orchids and grasses (with the major grain crops among them); bryophytes, including mosses and liverworts; pteridophytes, including ferns; gymnosperms, including conifers and cycads; and dicots, encompassing other plants.

Among plantae, Gymnosperms (especially conifers, Bennettitales and cycads) and ferns are common providing abundant food for the sauropods.

His current work also focuses on dissecting small RNA functions and biogenesis in Arabidopsis, maize, soybean, rice, asparagus, tomato, and numerous other plants, ranging from crops to gymnosperms to models to species of interest purely for evolutionary reasons.

From weather to electricity and simple machines to paleoclimates, gymnosperms, and symbiosis — there's a wide range of mini lessons here that include modules, quizzes, and links to additional resources.

BEACHCOMBERS TIP: of the two plant types angiosperms (flowering) and gymnosperms (seeds not in a seed case), these are flowering plants, with small non-descript flowers of a sort on the blades.

Vascular plants include ferns, club mosses, flowering plants, conifers and other gymnosperms.

This paper looks into the fate of gymnosperms.

Wiki says: «The gymnosperms are a group of seed - producing plants that includes conifers, cycads, Ginkgo, and gnetophytes.»

Angiosperms are seed - producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies (derived characteristics).