Classification of Living Organisms Practice Exam

These flashcards cover CHAPTER 2: Classification of Living Organisms, including binomial nomenclature, the 8 levels of taxonomy, characteristics of domains and kingdoms, prokaryotic structure, and viral/prion information.

How did Aristotle first classify living organisms?

He classified them into animals and plants.

Who is considered the founder of taxonomy and developed the binomial naming system?

Carolus Linnaeus

What are the two parts of a scientific name in the binomial naming system?

Genus and Species respectively.

What are the rules for writing the binomial name of an organism correctly?

The first letter of the Genus must be uppercase and the rest lowercase. If printed, it must be italicized; if handwritten, it must be underlined.

What is the correct scientific name for humans in the binomial system?

Homo sapiens

List the 8 levels of taxonomic classification from largest to smallest.

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

What term is used in place of phylum when classifying plants and bacteria?

Division

What characterizes the Species level of classification?

A group of organisms that share common traits and can reproduce to produce fertile offspring.

According to modern taxonomy, into how many domains and kingdoms are living organisms categorized?

3 Domains and 6 Kingdoms

What is the primary difference between the cell walls of Domain Bacteria and Domain Archaea?

Bacteria cell walls contain peptidoglycan, while Archaea cell walls do not.

Which domain contains organisms with membrane-bound organelles and includes kingdoms like Animalia and Plantae?

Eukarya

What are plant cell walls primarily composed of?

Cellulose

Name the three types of Archaea known for surviving in extreme environments.

Halophiles, Thermoacidophiles, and Methanogens.

What is the function of the capsule in a prokaryotic cell?

It is an outer protective layer that helps shield the cell from desiccation (drying out), antibodies, and white blood cells.

In Gram staining, what color indicates Gram-positive bacteria and why?

Dark purple, due to the presence of a thick layer of peptidoglycan in the cell wall.

Describe the difference between Binary Fission and Conjugation.

Binary Fission is asexual reproduction creating identical daughter cells; Conjugation is a form of genetic exchange involving direct cell-to-cell contact via a sex pilus.

If a Salmonella cell divides every $20$ minutes, how many cells will exist after $2$ hours?

The cell divides $6$ times, calculated as $2^6 = 64$ cells.

What is the role of Escherichia coli (E. coli) as normal flora in the human intestine?

It produces vitamin K, which is essential for blood clotting.

Which bacterial infection specifically affects the lungs' gas exchange capacity?

Tuberculosis

What are the two basic components that make up a virus?

Genetic material (DNA or RNA) and a protein coat.

What is a retrovirus, and what is a prominent example mentioned in the text?

A virus that contains RNA and uses reverse transcriptase to convert it into DNA; HIV is a prominent example.

What is the main difference between the Lytic and Lysogenic viral replication pathways?

In the Lytic pathway, the virus hijacks the host to produce new particles immediately; in the Lysogenic pathway, the viral genome integrates into the host's DNA and replicates with it.

What are prions, and what is one disease they cause?

Prions are proteinaceous infectious particles; they cause diseases such as Mad Cow Disease or Creutzfeldt-Jakob Disease.