Apbio

In the life cycles of a fern and a flowering plant, tally and contrast each of the following: The gametophyte generation. Both piss gametes that atomic number 18 haploid. In flowering plants, male and female gametophytes are start outd in the sporophyte, and are dependent on it for fodder. The male gametes are pollen grains, the females fertilized egg sacs. Each gametophyte develops from a different type of spore. In ferns, the archegonia produce eggs and antheridia produce sperm. The archegonia and antheridia are on the prothallus, which is a belief shaped structure. Archegonia has a neck and the venter, which contains the egg. The antheridia has a wall of cells harbor the gametes. The gametes dont depend on the prothallus, they are photosynthetic and have rhizoids for anchoring and water absorption. Sperm transport and fertilization In ferns, the transportation of sperm to the eggs for fertilizatio n needs a moist environment (for mobility). The cells of the neck distribution channel and adaxial canal disappear and releases a chemical that attracts the sperm. Fertilization takes tell in the venter of the archegonium. In flowering plants, pollen (the male gametes) travels from the anther to the dirt of the pistil.

A pollination agent is needed, such as a bee or a butterfly, needs to pollinate the egg. The pollen grain indeed germinates and grows done the style. Double fertilizations (2 sperm, 1 fertilized egg sac) happen by and by the pollen thermionic valve goes through the ovules. Emb ryo protection In ferns, sinc! e the embryo is in the archegonium during fertilization, it depends on it for protection as well. It is dependent on the gametophyte for nutrition in the early stages. In flowering plants the embryos are protected by seeds, much deal a chickens egg. The outer layer is hard, and makes up the ovule. When cover in a fruit, the fruit comes from the ovary wall. The ovary wall has third layers,...If you compulsion to get a full essay, order it on our website: BestEssayCheap.com

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