Answer to Question #184349 in Microbiology for Keiandra

Question

1. How do the protozoa and multicellular parasites compare with the bacteria in size and morphological features?

2. Explain the advantages of a wet mount preparation over a prepared slide? What disadvantages are there?

Answer 1

1.The agents of human infectious diseases belong to five major groups of organisms: bacteria, fungi, protozoa, helminths, and viruses. Bacteria belong to the prokaryote kingdom, fungi (yeasts and molds) belong to the kingdom of fungi, and protozoa are members of the kingdom of protists. Helminths (worms) are classified in the animal kingdom

a.Fungi are also eukaryotes.  Fungi are not photosynthetic, and their cell walls are usually made out of chitin rather than cellulose unlike bacteria which can also be photosynthetic like cyanobacteria and their cell wall -A peptidoglycan cell wall composed of disaccharides and amino acids .

b.Protists are distinguished from bacteria by being either unicellular or relatively simple multicellular organisms. Simple multicellular means they do not show division of labour. All cells carry out all functions. In addition they have well developed cell called eukaryotic cell. The bacteria on the other hand is unicellular and has prokaryotic (primitive cell without nuclear membrane). Prokaryotic cells (e.g., bacteria) replicate by binary fission, whereas eukaryotic cells replicate by mitosis.

c.Bacteria are compulsary unicellular organisms In contrast, helminths are complex multicellular organisms, showing division of labour and advanced body systems. They also have a sucker or hook for attachment with the body of the host unlike simple structures of locomotion possessed by bacteria (cilia and flagella).

Advantages of wet mount preparations are-:

a) Living organisms can be easily viewed with this kind of preparation.

b) Motility of living organisms can be also observed.

c) Specimen fixation, dehydration and fixation is not necessary.Hence, the characteristic arrangement of organisms is not disrupted.