BIO 102: General Biology II - Viruses, Bacteria, and Fungi

Practice questions covering the basic characteristics, identification, and classification of viruses, bacteria, and fungi based on the BIO 102 lecture transcript.

What are the primary modes of reproduction for viruses, bacteria, and fungi?

Viruses require host cells to replicate, bacteria reproduce via binary fission, and fungi reproduce via spores.

Why are viruses considered non-living acellular pathogens?

They lack cellular structures like cytoplasm, nucleus, and organelles; they cannot convert food into energy (metabolism); and they cannot live or reproduce without a host cell.

What is the difference between positive-sense RNA and negative-sense RNA in viruses?

Positive-sense RNA can be used directly as instructions to make virus parts, while negative-sense RNA must use special enzymes to create positive-sense RNA before making copies.

What is a viral capsid and what are its subunits called?

A capsid is a protein coat that protects the genetic material of a virus, and it is made up of subunits called capsomeres.

Compare the size of viruses to human body cells and a grain of sand.

Viruses are about $100-1000$ times smaller than human body cells, and the smallest viruses are about $2,000$ times smaller than a grain of sand.

According to the Baltimore classification, what characterizes Group VI and Group VII viruses?

Group VI consists of RNA with reverse transcriptase (Retroviruses), and Group VII consists of DNA with reverse transcriptase.

What characterizes the replication site of most DNA viruses compared to most RNA viruses?

Most DNA viruses replicate within the nucleus (except poxvirus), while most RNA viruses replicate within the cytoplasm (except influenza virus).

What is a bacteriophage?

A virus that specifically infects bacterial cells.

Match the bacterial shapes to their scientific names: Spherical, Rod-shaped, Spiral-shaped, and Comma-shaped.

Spherical: Cocci; Rod-shaped: Bacilli; Spiral-shaped: Spirilla; Comma-shaped: Vibrios.

What are the three main types of bacterial arrangement?

Chains (strepto-), Clusters (staphylo-), and Pairs (diplo-).

What material makes up the cell wall of bacteria?

Peptidoglycan.

Define the oxygen requirements for Aerobic, Anaerobic, and Facultative Anaerobes.

Aerobic bacteria require oxygen, anaerobic bacteria do not require oxygen, and facultative anaerobes can live with or without oxygen.

What are the temperature classifications for bacteria?

Psychrophiles (cold-loving), Mesophiles (moderate temperature lovers, includes most pathogens), and Thermophiles (heat-loving).

What is the causative agent of Typhoid fever?

Salmonella typhi.

What are the nitrogen-related functions of the bacteria Rhizobium, Nitrosomonas, and Nitrobacter?

Rhizobium converts atmospheric nitrogen into usable forms; Nitrosomonas converts ammonia into nitrites; and Nitrobacter converts nitrites into nitrates.

What is the study of fungi called?

Mycology.

What is the composition of a fungal cell wall and how do they store food?

The cell wall is made of chitin, and they store food as glycogen (unlike plants which store food as starch).

Define hyphae and mycelium in fungi.

Hyphae are thread-like structures that make up the body of fungi; a mass of these hyphae forms a mycelium.

Name the four main classifications of fungi based on reproductive structures.

Zygomycota (Zygomycetes), Ascomycota (Ascomycetes/sac fungi), Basidiomycota (club fungi), and Deuteromycota (imperfect fungi).

Provide an example of an edible mushroom and a poisonous mushroom mentioned in the text.

Edible: Agaricus bisporus; Poisonous: Amanita muscaria.