Archaea and Protists Lecture Review

These flashcards cover key concepts about Archaea and Protists from the lecture notes, including definitions, characteristics, and significance in ecosystems.

What are Archaea?

A large domain of single-celled prokaryotic microorganisms among the first life forms on Earth, present in most habitats including extreme environments.

When were Archaea recognized as a separate group from bacteria?

In 1977.

What is a characteristic difficulty in studying Archaea?

They are difficult to grow in the lab and to sample from their environments.

How do Archaea reproduce?

Through binary fission and can undergo horizontal gene transfer.

What are two types of nutrition in Archaea?

Autotrophs (can produce their own food) and heterotrophs (cannot produce their own food).

What is unique about archaeal DNA compared to bacteria?

Archaea have unique membrane lipids and similarities with eukarya in DNA replication and protein synthesis.

What are extremophiles?

Organisms that exist in extreme conditions that most life cannot tolerate, such as very hot, acidic, or salty environments.

What is methanogenesis?

A form of anaerobic respiration producing methane gas, performed only by some Archaea.

What defines protists?

Eukaryotic organisms that are not animals, plants, or fungi, often unicellular and diverse in form and function.

Why is the classification of protists complex?

Protists are polyphyletic, meaning they come from different ancestors despite being classified in the same group.

What is the role of protists in ecosystems?

They are important primary producers, forming the base of the ecological food web and performing a significant portion of the world's photosynthesis.

What are diatoms?

Unicellular algae with a unique two-part, glass-like wall of silicon dioxide, and a major component of phytoplankton.

How do dinoflagellates contribute to ecosystems?

They are abundant components of phytoplankton and can trigger toxic 'red tides'.

What disease is caused by the protist Plasmodium?

Malaria, transmitted by female Anopheles mosquitoes, which feed on red blood cells causing severe symptoms.

What is the significance of reading the assigned textbook chapters for exams?

It provides a deeper context to the material discussed in class, enhancing knowledge and retention.