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Obligate symbiotic fungi that form associations with plants by entering their cortical cells without invading the plant cells membrane are called endomycorrhizae and include the genus Glomus. Many plants form associations called mycorrhizae with fungi that give them access to nutrients in the soil, protecting against disease and toxicities. In these associations the fungi are integrated into the physical structure of the root, where the fungi colonize the living root tissue during active plant growth.
There is also a corresponding diffusion of Chinese and Japanese's forms along this zone
The reason for why celery stalk firms in water is because of its hypotonic environment and the salt content transfers into the celery stalk which makes the cell firm and significantly bigger.