heterospory
Quick Summary
Heterospory is a botanical term describing the production of two distinct types of spores: microspores and megaspores. This occurs in some vascular plants, known as pteridophytes, and all seed plants.12
Microspores develop into microgametophytes, which produce male gametes (sperm), while megaspores develop into megagametophytes, which produce female gametes (eggs). This contrasts with homospory, where only one type of spore is produced, leading to bisexual gametophytes. The evolution of heterospory, which occurred independently in several plant groups by the middle Devonian Period, is considered an advancement over homospory. It allows for obligate cross-fertilization, increasing genetic recombination and reducing mortality rates by enabling gametophytes to develop quickly within the protective spore wall.134
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plantHeterosporous life historiesA heterosporous life history occurs in some pteridophytes and in all seed plants. It is characterized by morphologically dissimilar spores produced from two types of sporangia: microspores, or male spores, and megaspores (macrospores), or female spores. In pteridophytes, megaspores are typically largerā¦
Read MoreA heterosporous life history occurs in some pteridophytes and in all seed plants. It is characterized by morphologically dissimilar spores produced from two types of sporangia: microspores, or male spores, and megaspores (macrospores), or female spores. In pteridophytes, megaspores are typically largerā¦
Read More- plantEvolution of land plants from the Ordovician Period through the middle Devonian
ā¦the middle Devonian Period, the heterosporous life cycle had evolved independently in several groups, including lycophytes and the ancestors of seed plants. In heterosporous plants, there are two sizes of spores; the smaller (a microspore) produces a male gametophyte, and the larger (a megaspore) produces a female gametophyte. The incidenceā¦
Read Moreā¦the middle Devonian Period, the heterosporous life cycle had evolved independently in several groups, including lycophytes and the ancestors of seed plants. In heterosporous plants, there are two sizes of spores; the smaller (a microspore) produces a male gametophyte, and the larger (a megaspore) produces a female gametophyte. The incidenceā¦
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fernSizeā¦Marsileaceae and Salviniaceae, is called heterospory.
Read Moreā¦Marsileaceae and Salviniaceae, is called heterospory.
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plant reproductive systemLycopsidsā¦all species of Selaginella are heterosporous; that is, they produce spores of two sizes, the larger designated as megaspores and the smaller as microspores. The megaspores develop into female gametophytes and the microspores into male gametophytes. Accordingly, strobili bear megasporophylls that contain megasporangia, which will produce megaspores, and microsporophylls thatā¦
Read Moreā¦all species of Selaginella are heterosporous; that is, they produce spores of two sizes, the larger designated as megaspores and the smaller as microspores. The megaspores develop into female gametophytes and the microspores into male gametophytes. Accordingly, strobili bear megasporophylls that contain megasporangia, which will produce megaspores, and microsporophylls thatā¦
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