Protists Lecture Notes

A comprehensive set of flashcards covering key concepts and terms about protists and their characteristics based on the provided lecture notes.

What are the key distinguishing features of eukaryotic cells compared to prokaryotes?

Eukaryotic cells have a cytoskeleton, compartmentalization (nucleus and organelles), and appeared in microfossils about 1.5 billion years ago.

What is endosymbiosis in the context of eukaryotic evolution?

Endosymbiosis is the process by which organelles such as mitochondria and chloroplasts evolved from engulfed bacterial cells.

What evidence supports the endosymbiotic theory?

Evidence includes the presence of DNA inside mitochondria and chloroplasts similar to bacterial DNA, ribosomes similar to bacteria, and the replication of these organelles via binary fission.

What key innovation allowed for the separation of chromosomes in eukaryotes?

The evolution of mitosis allowed eukaryotes to separate multiple chromosomes during cell division.

What defines the kingdom Protista?

Protists are the most diverse eukaryotic kingdom and are united by being neither fungi, plants, nor animals.

Which eukaryotic supergroups contain protists?

Protists are present in all six eukaryotic supergroups: Excavata, Chromalveolata, Archaeplastida, Rhizaria, Amoebozoa, and Ophisthokonta.

What are the modes of locomotion found in protists?

Modes of locomotion in protists include flagella, cilia, and pseudopodia.

What types of nutrition do protists exhibit?

Protists can be autotrophs (photosynthetic or chemoautotrophic) or heterotrophs (phagotrophs, mixotrophs).

How do protists typically reproduce?

Reproduction in protists is typically asexual; some can also reproduce sexually under certain conditions.

What is the significance of protists in the evolution of multicellularity?

Protists serve as a bridge to multicellularity, evolving from single cells to colonies and fostering specialization.

What are the main groups included in the supergroup Excavata?

Excavata includes diplomonads, parabasalids, and euglenozoans.

What are the main characteristics of diplomonads?

Diplomonads are unicellular, move with multiple flagella, have 2 nuclei, and lack functional mitochondria.

What adaptations do parabasalids have for survival?

Parabasalids live in termite guts, have a symbiotic relationship with bacteria, and use undulating membranes and flagella for locomotion.

What is a unique feature of euglenozoans?

Euglenozoans can change shape while swimming due to the absence of cell walls.

What is a characteristic of dinoflagellates?

Dinoflagellates are unicellular, photosynthetic organisms that can live in aquatic environments and some are luminescent.

What is the mode of reproduction in dinoflagellates?

Dinoflagellates primarily reproduce asexually but may reproduce sexually under starvation conditions.

What is the role of apicomplexans?

Apicomplexans are spore-forming animal parasites important for their unique organelle arrangement that enables host invasion.

How does Toxoplasma gondii affect humans?

Toxoplasma gondii invades epithelial cells and can cause infections, particularly in immunocompromised individuals and may harm fetuses.

What are diatoms and their unique features?

Diatoms are photosynthetic, unicellular organisms characterized by unique double shells made of silica.