Red Blood Cells: Red Blood Cells What are red blood cells, also known as erythrocytes, are red blood cells. The red blood cell is the largest element present in the blood. There are about 5 million red blood cells per cubic millimeter in the blood of a healthy adult man (about 4.5 million in women).

Rotavirus (microscope image) What is Rotavirus is an infectious disease caused by the virus of the genus rotavirus. It most severely affects children under the age of five. Symptoms Its main symptoms are severe diarrhea, vomiting and high fever. In adults such symptoms may present more mildly.

Fern: Most Common Example of Pteridophytes What They Are Pteridophytes are vascular plants that have no seeds. Main features - Chorus composed by root, stem and leaves; - They are tracheophytes, that is, they have a conduction system that transports the sap from the roots to the leaves. In these ducts are also transported food to the rest of the body; - Have leaves divided into leaflets; - New leaves appear rolled up; - Most species have sexual reproduction, but some can reproduce asexually through budding.

Ruminant animals: two-step digestion What they are - biological definition Ruminants are herbivorous mammal animals belonging to the suborder Ruminantia. These animals perform the digestion in two phases. Main characteristics of ruminanes: - The main characteristic of these animals is the digestion of the food in two stages: in the first stage they chew and swallow the food (mainly herbs, vegetables and grasses).

Earthworm: An example of annelid What they are - biological definition Annelids are invertebrate, vermiform-looking animals that have their bodies segmented into rings. The Anellida phylum is large and diverse, with about 16,500 species (known so far). Habitat Annelids, according to species, live in terrestrial and marine environments.

Herbaceous Vegetation: Short Life Cycle Introduction (what it is) The term herbaceous vegetation defines what is popularly known as herbs. It does not designate a taxonomic group defined by scientists because it brings together many species not necessarily related to each other. The stems of these plants are flexible, that is, they are not woody like the stems of shrubs and trees.