What is the life cycle of a conifer?
What is the life cycle of a conifer?
Pine trees are conifers (cone bearing) and carry both male and female sporophylls on the same mature sporophyte. Therefore, they are monoecious plants. Like all gymnosperms, pines are heterosporous, generating two different types of spores: male microspores and female megaspores.
What is the lifecycle of a gymnosperm?
The life cycle of a gymnosperm involves alternation of generations, with a dominant sporophyte in which reduced male and female gametophytes reside. All gymnosperms are heterosporous. The male and female reproductive organs can form in cones or strobili.
What is the life cycle of angiosperms?
The adult, or sporophyte, phase is the main phase of an angiosperm’s life cycle. As with gymnosperms, angiosperms are heterosporous. Therefore, they generate microspores, which will produce pollen grains as the male gametophytes, and megaspores, which will form an ovule that contains female gametophytes.
Is cone a gametophyte?
In gymnosperms, the gametophyte generation takes place in a cone, which forms on the mature sporophyte plant. Each male gametophyte is just a few cells inside a grain of pollen. Each female gametophyte produces an egg inside an ovule.
What are the six steps of a conifers lifecycle?
Life cycle of a conifer tree
- Life Cycle of a Conifer Tree.
- Female cone Male cone Most coniferous trees have both male and female cones. Female cones contain eggs. Male cones are small and soft. They make pollen.
- The seeds grow at the bottom of the scales. The seeds can grow for two years. Growing Seed.
Do conifers have ovaries?
Gymnosperms derive their name (which means “naked-seeded”) from the fact that their ovules and seeds are not protected by ovary or fruit tissue. In conifers, the same diploid sporophyte plant has both pollen-producing strobili and egg-producing cones.
What is the most recognizable gymnosperm?
Gymnosperms are vascular plants of the subkingdom Embyophyta and include conifers, cycads, ginkgoes, and gnetophytes. Some of the most recognizable examples of these woody shrubs and trees include pines, spruces, firs, and ginkgoes.
What life cycle stage is pollen?
What is a female cone called?
The female cone (megastrobilus, seed cone, or ovulate cone) contains ovules which, when fertilized by pollen, become seeds. The female cone structure varies more markedly between the different conifer families, and is often crucial for the identification of many species of conifers.
Are conifers asexual?
The two main forms of reproduction in flowering plants and conifers are sexual by means of seeds and asexual by means of separating and rooting part of a plant, cloning the mother plant. For all conifers and flowering plants, however, seeds are the basic means of perpetuating a species.
What are the female gametophytes of a conifer like?
The female gametophytes of conifers are more massive and complex than their male counterparts and basically resemble gametophytes of Ginkgo and the cycads. The life history of the female gametophyte begins with a protracted series of free nuclear divisions in the megaspore.
How are gametes formed in a conifer tree?
The conifers have their reproductive parts enclosed in protective structures that are called cones. These are hard and tough structures in which the gametes are manufactured. The female and male sex cells (gametes) are formed in different and separate cones that occur on the same tree.
Where does the male gametophyte go in a gymnosperm?
The male gametophyte is released, as pollen, from the male cones. Cones: The reproductive structures of gymnosperms. Female cones are larger. Meiosis produces megaspores (haploid), which will develop into female gametophytes, which are retained in the female cone.
Which is the longest phase of the conifer life cycle?
The seed that is formed contains three generations of tissues: the seed coat that originates from the sporophyte tissue, the gametophyte that will provide nutrients, and the embryo itself. In the life cycle of a conifer, the sporophyte (2n) phase is the longest phase.