1st ESO

3rd ESO

4th ESO

Biology 2nd Baccalaureate

Index by courses



Skip navigation

12.3. Other acellular forms

Other acellular forms

Besides viruses, there are other types of infectious acellular pathogens. Although they were initially identified as viruses, they have different characteristics. They are viroids and prions.

Interactive activity: Acellular shapes.

Questions that have come out in University entrance exams (Selectividad, EBAU, EvAU)

Castilla y León, July 2020, question 5

a) Explain the differences between viruses, viroids, and prions. Please indicate any application of viruses using genetic engineering. (1,0)
b) What types of microorganisms participate in biogeochemical cycles such as nitrogen? What kind of nutrition can bacteria present? (1.0)

La Rioja, June 2021, question 15

Explain the differences between viruses, viroids, and prions. Draw a virus and label its components.


Legal warning






Follow us if it has been useful to you

Biology and Geology teaching materials for Compulsory Secondary Education (ESO) and Baccalaureate students.