12.Biological Diversity (Part 2: Protists & Fungi) Flashcards
(22 cards)
What are protists?
A taxonomic group of mostly unicellular eukaryotic organisms; can be autotrophs or heterotrophs; often found in moist environments.
How do protists reproduce?
Asexually.
What relationships can protists form?
They can be symbiotic or free-living.
What are the three categories of protists?
1) Plant-like, 2) Fungus-like, 3) Animal-like (protozoa).
What are plant-like protists?
Photosynthetic autotrophs found in water; contain chloroplasts; use photosynthesis; examples: red algae, euglenoids.
What are fungus-like protists?
‘Slime molds’ or ‘water molds’; reproduce via spores; do not contain chitin; are heterotrophic decomposers or saprobes.
What are animal-like protists (protozoa)?
Single-celled heterotrophs capable of movement; categorized by motility (cilia or flagella); can engulf food via phagocytosis; examples: amoebas, ciliates.
What is an amoeba?
Example of an animal-like protist; moves using pseudopodia (temporary arm-like projections).
What is pseudopodia?
Temporary arm-like projections consisting mainly of cytoplasm, used for movement in amoebas.
What are the general structures of fungi?
Can be unicellular or multicellular; cell walls contain chitin.
What is a sporangium?
A multicellular organ where meiosis occurs to form haploid spores.
What are rhizoids?
Small branching hyphae that anchor fungi to the ground; unlike roots, they lack tissues and specialized conducting cells.
What is mycelium?
A network of fungi filaments (hyphae) connecting fungi together; secrete enzymes to break down organic matter and absorb nutrients.
Why are fungi effective decomposers?
Mycelium breaks down organic matter, releasing nutrients for absorption.
Are fungi autotrophic or heterotrophic?
All fungi are heterotrophic saprophytes.
How do fungi reproduce?
Sexually, asexually, or both; they are haploid for most of their life cycle.
What are hyphae?
Filamentous branches produced by multicellular fungi as they grow.
What are septate hyphae?
Hyphae with septa (cell walls) separating individual cells.
What are coenocytic hyphae?
Hyphae with no divisions (no cytokinesis during cell division); they are multinucleated.
What are non-filamentous fungi?
Unicellular fungi like yeasts; reproduce asexually by budding via mitosis.
How does yeast budding work?
Replicates genetic material, then pinches off cytoplasm and membrane to form a new cell.
What are filamentous fungi?
Multicellular fungi like molds and mushrooms; can reproduce sexually or asexually; mushrooms grow outward from the mycelium.
