What are three types of parasitic worms?
There are three main groups of helminths (derived from the Greek word for worms) that are human parasites:
- Flatworms (platyhelminths) – these include the trematodes (flukes) and cestodes (tapeworms).
- Thorny-headed worms (acanthocephalins) – the adult forms of these worms reside in the gastrointestinal tract.
Are parasitic worms bacteria?
Parasites are part of a large group of organisms called eukaryotes. Parasites are different from bacteria or viruses because their cells share many features with human cells including a defined nucleus. Parasites are usually larger than bacteria, although some environmentally resistant forms are nearly as small.
Is virus parasite or bacteria?
Bacteria and viruses can live outside of the human body (such as on a countertop) sometimes for many hours or days. But parasites need a living host to survive. Bacteria and parasites can often be killed with antibiotics. But these medicines can’t kill viruses.
Is virus a parasite or not?
They are similar to obligate intracellular parasites as they lack the means for self-reproduction outside a host cell, but unlike parasites, viruses are generally not considered to be true living organisms.
What are the 2 main parts of a virus?
The simplest virions consist of two basic components: nucleic acid (single- or double-stranded RNA or DNA) and a protein coat, the capsid, which functions as a shell to protect the viral genome from nucleases and which during infection attaches the virion to specific receptors exposed on the prospective host cell.
What are the 3 basic shapes of viruses?
- Viruses are classified into four groups based on shape: filamentous, isometric (or icosahedral), enveloped, and head and tail.
- Many viruses attach to their host cells to facilitate penetration of the cell membrane, allowing their replication inside the cell.
What is the most common virus in humans?
The most common type of viral disease is the common cold, which is caused by a viral infection of the upper respiratory tract (nose and throat). Other common viral diseases include: Chickenpox. Flu (influenza)