Which of the following sequences best represents the life cycle of a typical angiosperm?
Flowering plants are termed angiosperms. The flowering plants are the most dominant vascular plants that are found all around the world. Here, let us learn more about the life cycle of angiosperms in detail. Phanerogams or spermatophytes are a plant division that comprises plants that bear seeds. This includes the
gymnosperms as well as the angiosperms. Angiosperms are a plant group with flowers that produce seeds enclosed within a carpel. In other words, these are flowering plants that produce seeds within a fruit. Whereas gymnosperms are a plant group comprising seed-bearing plants with seeds unprotected by a fruit. Examples – conifers, cycads, etc. Examples of angiosperms – Roses, lilies, eggplant, tomato, rice, wheat, mango, etc. These plants typically have well-differentiated
bodies with fully developed shoot and root systems. They can survive in various habitats. Angiosperms – Taxonomy The taxonomy of angiosperms is based on several primitive and advanced characteristics proposed by many systematists like Linnaeus and Takhtajan. Their ideas established different principles in taxonomy which are now helping us to understand the concept of angiosperms’ phylogeny.
Kingdom Plantae Division Spermatophyta Infradivision Angiosperms Angiosperms were formerly termed Magnoliophyta. This division of flowering plants is further divided into 2 classes:
Here, the Magnoliopsida includes a few primitive angiosperms. They typically bear orthotropous ovules. See more:Difference between Anatropous and Orthotropous Ovule Darwin has described the origin of angiosperms as a mystery. Angiosperms are said to have originated during the cretaceous period. Angiosperm – ReproductionThe flower is the reproductive structure of an angiosperm and can be either unisexual or bisexual. One of its primary duties is to reproduce seeds through sexual reproduction. Also double fertilisation is a characteristic feature of Angiosperms. Here, one female gamete unites with two male gametes. After fertilisation, the ovary forms the fruit, and the ovules form the seeds while the remaining parts wither off. The angiosperm life cycle typically demonstrates the alternation of generations with haploid gametophyte and diploid sporophyte alternation. The sporophyte stage is the primary period of an angiosperm’s life cycle. Angiosperms are heterosporous. This means they produce bigger megaspores and smaller microspores.
Significance of FertilisationMuch of agriculture is solely dependent on angiosperms. Thus the fertilisation process invariably leads to great economic significance. They help in giving a new genetic identity to the zygote. After fertilisation, the ovary tissue forms the fruit and the ovule becomes the seed. Moreover, the double fertilisation feature is unique to the angiosperms. It gives rise to endosperm tissue which acts as a food reserve and provides nourishment to the developing embryo. This further increases the seed viability. Keep exploring BYJU’S Biology to learn more such exciting topics. Also Check: Recommended Video:Frequently Asked QuestionsMicrosporophylls are structures that bear one or more microsporangia. The microsporophyll of angiosperm is known as stamens. They bear the anthers, which are the microsporangia. Microsporophylls are also found in gymnosperms, where they mostly aggregate to form a strobili. Both gymnosperms and angiosperms produce seeds, but the distinction is seen in the position of these seeds. In angiosperms, the seeds are enclosed within the fruit, whereas in gymnosperms, the seeds are naked or unenclosed. Examples – Cycads, ginkgo, pine, etc. Examples of angiosperms – Tomato, lilies, roses, etc. Angiosperms are classified based on their cotyledons. Monocotyledonous angiosperms (1 cotyledon) typically have trimerous flowers, adventitious roots and parallel venation. Example – banana. The dicotyledonous angiosperms (2 cotyledons) have tetramerous or pentamerous
flowers and taproot system. Example – sunflower. Capsella is a prominent angiosperm because it possesses enclosed seeds. It is a heterosporous herbaceous plant that belongs to the mustard family. What is the order of a life cycle for an angiosperm?The angiosperm life cycle consists of a sporophyte phase and a gametophyte phase. The cells of a sporophyte body have a full complement of chromosomes (i.e., the cells are diploid, or 2n); the sporophyte is the typical plant body that one sees when one looks at an angiosperm.
What type of fertilization is represented here characteristic of angiosperms?As mentioned above, angiosperms have double fertilization. One sperm fuses with the egg to make a diploid zygote, the single cell that through division, growth, and development will eventually yield a sporophyte embryo. The other sperm fuses with the polar nuclei to form a primary endosperm nucleus.
Which of the following best describes double fertilization in angiosperms?1: Double fertilization: In angiosperms, one sperm fertilizes the egg to form the 2n zygote, while the other sperm fuses with two polar nuclei to form the 3n endosperm. This is called a double fertilization.
What are the products of meiosis in the life cycle of seed plants?Pollen development in seed plants begins with microspore mother cells (pollen mother cells) that differentiate in the microsporangia (pollen sacs). Each of the microspore mother cells undergoes meiosis to produce a tetrad (group of four) microspores. Each microspore then divides to form a pollen grain.
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