plankton. n. 1. (Biology) the organisms inhabiting the surface layer of a sea or lake, consisting of small drifting plants and animals, such as diatoms.Compare nekton. [C19: via German from Greek planktos wandering, from plazesthai to roam].lankton is a primary food source for many animals, and consists of bacteria, protozoans, certain algae, cnidarians, tiny crustaceans such as copepods, and many other organisms. Microscopic aquatic organisms that float near the surface of water.
Descriptions of Common Tomato Diseases. 1  Anthracnose - small, circular, slightly sunken spots... 2  Bacterial Canker - wilting, browning plants and bird's-eye fruit spots. 3  Bacterial Spot - small, dark, slightly raised dots on fruit... 4  Bacteria Wilt - entire plant dies rapidly after browning... 5  Blossom End Rot - spot on bottom of fruit turns black and...
Tomatoes are fun to grow, but they are susceptible to many infections. Tomato diseases are caused by bacteria, fungi, and viruses. They spread through the soil, water supply, air, infected tools, animals, and gardeners. Fortunately most are usually not fatal. The key is to identify a disease early so you can treat it before it overtakes the plant and then manage symptoms successfully.