A flagellate is an organism with one or more whip-like organelles called flagella. Some cells in may be flagellate, for instance the spermatozoa of most phyla. do not produce flagellate cells, but , , green algae, some gymnosperms and other closely related plants do. Likewise, most fungi do not produce cells with flagellae, but the primitive fungal do. Many take the form of single-celled flagellates.
Conversation threading is a feature used by many email clients, , , and in which the software aids the user by visually grouping messages with their replies. These groups are called a conversation, topic thread, or simply a thread. A discussion forum, e-mail client or news client is said to have a "conversation view", "threaded topics" or a "threaded mode" if messages can be grouped in this manner.