Biology Class 11 NCERT Solutions Chapter 3 Plant Kingdom Part 3 FlexiPrep
What Is Heterospory. These microspores and megaspores are formed respectively within microsporangia and megasporangia which in turn are borne on two distinct sporophylls called microsporophylls and megasporophylls respectively. The larger spore is called a megaspore which leads to forming a female gametophyte.
Biology Class 11 NCERT Solutions Chapter 3 Plant Kingdom Part 3 FlexiPrep
The larger spore is called a megaspore which leads to forming a female gametophyte. The smaller one is known as microspore and the larger one is known as megaspore. Microspores and megaspores in a single plant. It is defined as the production of two spores that are different in size in the same plant. The heterosporous condition has been observed in many families of flowering plants, including the grasses and sedges and some conifers. These spores differ in size. The smaller spore is known as a microspore which germinates to form a male gametophyte. The two phases, or generations, are often morphologically,. Examples of heterospory plants are selaginella, salvinia, and marsilea, etc. The smaller of these, the microspore , is male and the larger megaspore is female.
In heterosporous forms the differentiation of sex can be predicted at the spore stages. The clubmosses , the ferns including the arborescent. The microspore germinates to form the male gametophyte and the megaspore germinates to form the female gametophyte. Web alternation of generations, also called metagenesis or heterogenesis, in biology, the alternation of a sexual phase and an asexual phase in the life cycle of an organism. Web heterospory is the formation of two morphologically different spores (megaspores and microspores) from the sporophytes of pteridophytes and other seed plants. The smaller one is known as microspore and the larger one is known as megaspore. The heterosporous condition has been observed in many families of flowering plants, including the grasses and sedges and some conifers. The megaspores are the bigger spores that produce a female gametophyte and the microspores are the smaller ones that produce a male gametophyte. Web heterospory, defined as the production of smaller male microspores and larger female megaspores, arose independently in all major vascular plant lineages (lycophytes, monilophytes and spermatophytes) and is considered a key innovation for terrestrial colonization (bateman & dimichele, 1994; The female gametophyte never outgrows the limits of the megaspore. Web heterospory is the production of spores of two different sizes and sexes by the sporophytes of land plants.
