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Male nematodes may have one or two spicules which serve to open the vulva of females and facilitate the transmission of sperm, although sperm is not transferred directly by or through the spicules. [2] [3] The gubernaculum is another organ of the nematode male copulatory system which guides the spicules during copulation.
Extremity of a male nematode showing the spicule, used for copulation, bar=100 μm [48] Most nematode species are dioecious, with separate male and female individuals, though some, such as Caenorhabditis elegans, are androdioecious, consisting of hermaphrodites and rare males. Both sexes possess one or two tubular gonads. In males, the sperm ...
Plant reproductive morphology is the study of the physical form and structure (the morphology) of those parts of plants directly or indirectly concerned with sexual reproduction. Among all living organisms, flowers , which are the reproductive structures of angiosperms , are the most varied physically and show a correspondingly great diversity ...
Longidorus is a genus of needle nematodes. Some of its species are plant pests. [1] [2] [3] They may also transmit important plant viruses [4] such as the potato virus U or the cacao necrosis virus. Species are known to infest narcissus, alfalfa, beet, caneberries, lettuce, grape and citruses
The nematodes survival stage is to remain anhydrobiotic in seed until planting. As surrounding plants grow the nematodes become active and feed on meristematic tissue. A. besseyi reproduces amphimicticly although parthenogenesis can take place. As the plant begins to reach reproductive maturity the number of nematodes increases dramatically.
Parthenogenesis occurs naturally in some plants, algae, invertebrate animal species (including nematodes, some tardigrades, water fleas, some scorpions, aphids, some mites, some bees, some Phasmatodea, and parasitic wasps), and a few vertebrates, such as some fish, amphibians, and reptiles. This type of reproduction has been induced ...
Sperm cells are carried out of the male body in a fluid known as semen. Human sperm cells can survive within the female reproductive tract for more than 5 days post coitus. [15] Semen is produced in the seminal vesicles, prostate gland and urethral glands.
Plant reproduction is the production of new offspring in plants, which can be accomplished by sexual or asexual reproduction. Sexual reproduction produces offspring by the fusion of gametes , resulting in offspring genetically different from either parent.