Types of eye twitching. Minor eyelid twitch also can be caused by irritation of the surface of the eye ( cornea) or the membranes lining the eyelids (conjunctiva). Sometimes the cause of minor eyelid twitch cannot be identified. In almost all cases it is painless and harmless.
Roots are not simply smooth, long structures. In fact, they typically have tiny hairs that cover most of the roots' length. These hairs absorb water and soluble nutrients for plant success. However, some critical nutrients, like phosphorus, are not readily absorbed by plant root hairs. Soil micro-organisms, such as earthworms, consume the surrounding elements and expel castings rich in soluble elements.
Unseen and buried beneath the soil, plant roots perform functions that are necessary to a plant's life. The roots collect water and nutrients for the plant and secure it to the soil. Two basic types of root systems exist. One type is the taproot, which grows vertically and has lateral branches. The other type has fibrous, branching roots that make a network close to the soil surface. Some plants have either a taproot or fibrous roots, and other plants combine the two systems.