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Flowering plants contain microsporangia in the anthers of stamens (typically four microsporangia per anther) and megasporangia inside ovules inside ovaries. In all seed plants, spores are produced by meiosis and develop into gametophytes while still inside the sporangium. The microspores become microgametophytes (pollen).
Spores form part of the life cycles of many plants, algae, fungi and protozoa. [2] They were thought to have appeared as early as the mid-late Ordovician period as an adaptation of early land plants. [3] Bacterial spores are not part of a sexual cycle, but are resistant structures used for survival under unfavourable conditions. [4]
The stages of germination of a pea plant: A. seed coat, B. radicle, C. primary root, D. secondary root, E. cotyledon, F. plumule, G. leaf, H. tap root. The part of the plant that first emerges from the seed is the embryonic root, termed the radicle or primary root. It allows the seedling to become anchored in the ground and start absorbing water.
In lichens and other fungi, the sorus is surrounded by an external layer. In some red algae, it may take the form of depression into the thallus. In ferns, the sori form a yellowish or brownish mass on the edge or underside of a fertile frond.
Under certain stressors such as heat or starvation, plants select for microspore embryogenesis. It was found that over 250 different species of angiosperms responded this way. [ 6 ] In the anther , after a microspore undergoes microsporogenesis , it can deviate towards embryogenesis and become star-like microspores.
Cladosporium cladosporioides occurs outdoor environments year-round with peak spore concentration in the air occurring in summer where levels can range from 2,000 spores up to 50,000 spores per cubic meter of air. [16] It is among the most common of all outdoor airborne fungi, [16] colonizing plant materials and soil. [14]
This occurs when plants are overwatered and may require repotting in severe cases. Broken pot. Of course, if your plant’s pot breaks, it’s definitely time for a new pot. Pests. Most houseplant ...
Early land plants had sporophytes that produced identical spores (isosporous or homosporous) but the ancestors of the gymnosperms evolved complex heterosporous life cycles in which the spores producing male and female gametophytes were of different sizes, the female megaspores tending to be larger, and fewer in number, than the male microspores ...