Prions are misfolded proteins that can transmit their abnormal shape onto normal variants of the same protein, causing a chain reaction of protein misfolding in the host organism.They are unique infectious agents because, unlike bacteria, viruses, or fungi, they contain no nucleic acids (DNA or RNA). Their infectivity arises solely from their altered protein conformation.

Parasitology is the scientific study of parasites, their biology, ecology, interactions with hosts, and the diseases they cause. It is an interdisciplinary field drawing from zoology, microbiology, immunology, pathology, ecology, and medicine.A parasite is an organism that lives on or inside another organism (the host), deriving nutrients at the host's expense and often causing harm.

Medical microbiology is the branch of microbiology that deals with the study of microorganisms (bacteria, viruses, fungi, and parasites) that cause diseases in humans.

Phycology, also known as algology, is the scientific study of algae, a diverse group of predominantly aquatic, photosynthetic organisms that range from unicellular microalgae to multicellular forms like seaweeds.

Botany is the branch of biology that deals with the scientific study of plants, including their structure, properties, biochemical processes, classification, physiology, ecology, and economic importance.

Microbiology is the scientific study of microorganisms, which are microscopic organisms including bacteria, archaea, viruses, fungi, protozoa, and algae.

Biochemistry is the branch of science that explores the chemical processes and substances occurring within living organisms, bridging biology and chemistry to understand life at the molecular level.

Molecular biology is a branch of biology that focuses on the molecular basis of biological activity within and between cells, particularly the interactions between DNA, RNA, proteins, and their synthesis.

Genetics is the branch of biology that deals with the study of genes, genetic variation, and heredity in living organisms.

Cell biology, also known as cytology, is the branch of biology that studies the structure, function, and behavior of cells. Cells are the fundamental units of life, and understanding them provides insights into how organisms grow, reproduce, and carry out essential processes.

Anatomy is the branch of biological science concerned with the study of the structure and organization of living organisms, particularly the human body.