Are seed plants Homosporous or heterosporous?

Are seed plants Homosporous or heterosporous?

Are seed plants Homosporous or heterosporous?

Whereas lower vascular plants, such as club mosses and ferns, are mostly homosporous (producing only one type of spore), all seed plants, or spermatophytes, are heterosporous, producing two types of spores: megaspores (female) and microspores (male).

Are all land plants heterosporous?

All plants that produce seeds are heterosporous plants, so the seed habit involves further modifications beyond simple heterospory. These include the evolution of the ovule and seed, as well as the pollen grain.

What are the 4 characteristics common to all seed plants?

Section 3: Seed Plants. List four characteristics common to all seed plants. Seed plants have roots, stems, leaves, vascular tissue, and produce seeds.

What are the ideal characteristics of seed?

Characteristics of good quality seed

  • Higher genetically purity:
  • Higher physical purity for certification.
  • Possession of good shape, size, colour, etc., according to specifications of variety.
  • Higher physical soundness and weight.
  • Higher germination ( 90 to 35 % depending on the crop)
  • Higher physiological vigour and stamina.

How are heterosporous plants different from exosporic plants?

While heterosporous plants produce fewer megaspores, they are significantly larger than their male counterparts. In exosporic species, the smaller spores germinate into free-living male gametophytes and the larger spores germinate into free-living female gametophytes.

How are heterospory and endospory related to each other?

Modern heterosporous plants such as many ferns exhibit endospory, in which a megagametophyte is fertilized by a microgametophyte all while still inside the spore wall, gaining nutrients from the inside of spore. Both heterospory and endospory seem to be one of the many precursors to seed plants and the ovary.

How is heterospory related to the production of megaspores?

Heterospory is the production of spores of two different sizes and sexes by the sporophytes of ... While heterosporous plants produce fewer megaspores, they are significantly larger than their male counterparts. In exosporic species, the smaller

How does heterospory stop self fertilization in angiosperms?

Heterospory stops self-fertilization from occurring in a gametophyte, but does not stop two gametophytes that originated from the same sporophyte from mating. This specific type of self-fertilization is termed as sporophytic selfing, and it occurs most commonly among angiosperms.


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