Symbiosis and parasitism

A.Y. 2021/2022
Overall hours
BIO/02 BIO/05
Learning objectives
At the end of this course the students will become familiar with the symbiotic and parasitic associations and their biology, receiving information about the major parasitic diseases of humans and animals. The course addresses the concept of symbiosis and parasitism in the plant kingdom too, starting from the origin of the plant cell, moving to the concept of soil microbiome by discussing the agricultural effects of bio-stimulants. During the lectures some association will be described in detail.
Expected learning outcomes
Learning outcomes expected at the end of the course: the student will be able to describe and interpret the different types of symbiosis, describing the main pest relationships, analyzing the biological cycles, the transmission mechanisms and the strategies of coexistence and coevolution host/parasite.
Course syllabus and organization

Single session

Lesson period
Second semester
More specific information on the deluvery modes of training activities for academic year 2021/2022 will be provided over the coming months, based on the evolution of the public health situation.
Unless otherwise prescribed due to the rules on social distancing, the exam will consist of an oral test to verify the knowledge of all the topics covered. If necessary, the oral exam can take place electronically on the Zoom / Teams platform.
For further details, see: Learning assessment procedures and assessment criteria and Reference material.
Course syllabus
Definitions: symbiosis, parasitism, mutualism.
History of the concept of symbiosis and its declinations. Importance of symbiosis during evolution: origin of the eukaryotic cell, vertical transmission and integration of information between partners.
Parasitism in animals: ecology, epidemiology and evolutionary aspects; basic principles and terminology in medical/veterinary parasitology; pathogenesis, virulence and evolution of host-parasite interactions; biology of platelmintes (Taenia spp. and Echinococcus spp.); biology of pematodes (Trichinella spp., Ascaris spp. and others), Strongyloides spp.); ticks, and a general introduction to vector arthropods; protozoan diseases, with particular reference to toxoplasmosis, leishmaniasis, trypanosomiasis and malaria; helminth diseases, with particular reference to filariasis and schistosomiasis; tick-borne diseases, with particular Lyme disease.

Origin of the plant cell (the chloroplast, examples of tertiary and quaternary symbiosis). Associations between plant organisms: definitions and limits. Symbiosis between plants and nitrogen fixators: Azolla and other symbiosis with cyanobacteria and Rhizobia. Soil microbiome, biostimulants and agriculture. Associations between plants and fungi: mycorrhizae (micorrhizae of heathers and orchids). Parasite plants: holoparasite and hemiparasite plants, obligatory or facultative plants. Description of the mechanisms involved in plant parasitism, ecology of the parasitic plants and tehir origin and evolution (two examples: dodder and mistletoe). Weeds.
Prerequisites for admission
It is recommended to have good knowledge of zoology, anatomy, botany and cytology and animal and plant histology.
Teaching methods
he course is based on frontal lessons supported by projected material. The students are invited to actively participate to the discussion to improve their critical skills, re-elaborating the acquired concepts.
Teaching Resources
Powerpoint lessons are available for students in ARIEL. Furthermore, scientific articles, links to seminars, movies etc are provided to support the lessons.
Assessment methods and Criteria
The information acquired are verified through an oral exam, divided in two phases: the first one dedicated to animal symbiosis and parasitism and the second to the plant topics. The student can present a topic of his/her choice agreed with the teacher (also by reading a scientific article) concerning either the first or second part of the course. The evaluation also takes into account the ability to discuss and comments. The final grade is expressed in 30/30 and is the weighted average of the marks obtained in the two parts of the course.
BIO/02 - SYSTEMATIC BOTANY - University credits: 0
BIO/05 - ZOOLOGY - University credits: 0
Lessons: 48 hours
Educational website(s)