Bio Unit Test 1 Flashcards
When did protists first appear?
1.5 billion years ago
How big are protists (eukaryotes) in relation to prokaryotes?
10 times bigger than prokaryotes.
What made eukaryotes different from prokaryotes?
10 times bigger, had many chromosomes and organelles with their own membranes.
What is endosymbiosis?
The relationship in which single-celled organisms live within the cells of another organism.
Where did membrane bound organelles likely develop?
From the folded cell membrane of ancestral prokaryotic cells.
What makes mitochondria and chloroplasts different from other organelles?
They have their own DNA. They reproduce on their own.
What are protozoans?
Protists that eat or ingest material from their surroundings. (animal-like and were once classified as animals).
What are some examples of protozoans?
Zoo-flagellates, amoebas, ciliates.
What are the characteristics of a zooflagellate?
They have one or more flagella. Some are heterotrophic (feed on protists) and some are parasites (take nutrients from a host).
Name a possibly fatal sickness that is caused by a parasitic zooflagellate.
African sleeping sickness
What are amoebas?
Single-celled protozoans with no real body shape.
What do amoebas use to move and feed?
Temporary projections called pseudopods.
How does an amoeba eat?
By endocytosis.
What is endocytosis?
When particles of food are sealed off in food vacuoles in the cytoplasm.
What are ciliates?
Protozoans covered in cilia.
Name some characteristics of ciliates.
They have a rigid outer covering (pedicle/pellicle), 2 nuclei. They are aquatic, hetertrophic, and live in salt/fresh water.
What purpose does the pellicle of a ciliate serve?
Maintaining their shape.
Give an example of a freshwater ciliate.
Paramecium
Explain how ciliates eat.
- Beat cilia to bring food into their oral groove.
- The membrane pinches off and forms a food vacuole.
- The food vacuole travels into the cytoplasm.
- The food vacuole joins with a lysosome that breaks down the food.
- The unwanted is discharged through the anal pore.
How do ciliates reproduce?
Through binary fission mostly. Sometimes through conjugation.
What are fungus-like protists?
Heterotrophic decomposers that live in cool and damp habitats.
What are the 3 major phyla of fungus-like protists?
- Acellular slime moulds (live in colonies), cellular slime moulds, and water moulds.
What are sporozoans?
Protist that make spores.
What are some characteristics of sporozoans?
Non-motile and parasitic.
What is the most known sporozoan?
Plasmodium (causes malaria).
How do plasmodia infect humans with malaria?
- Spend part of their life cycle within human red blood cells.
- Red blood cell bursts open.
- The parasite’s toxins fill the bloodstream.
What are plant-like protists?
Multicellular protists that contain chlorophyll and undergo photosynthesis.
How do plant-like protists differ from plants?
The zygote of the alga is unprotected. The zygote of a plant is protected by the parental cells. Plant-like protists do not have tissues.
What are euglenoids?
Unicellular flagellates.
How does the euglena propel itself through water?
By using its flagellum.
What happens to euglenoids in the sunlight vs the dark?
Sunlight: autotrophic.
Dark: Lose its chlorophyll, becomes heterotrophic.
What are some characteristics of algae?
They all have chloroplasts, some are single-celled, some live in colonies, some are multicellular.
What are the 3 main groups of algae (the ones we have to know)?
Diatoms, dinoflagellates, green algae.
What are the characteristics of diatoms?
Yellow-brown, glass-like silica shells.
What are the characteristics of dinoflagellates? (6)
Singled-celled, 2 flagella, photosynthetic (most), move in spinning motion, can be luminescent, reproduce asexually.
What can dinoflagellates cause with their blooms?
Red tides.
Why are red tides bad?
They produce toxins.
What are the characteristics of green algae?
Single-celled or colonial,
2 flagella,
fresh water,
cellulose in their cell walls.
From what do we think plants originated from? Why?
Green algae because they have cellulose in their cell walls.
What are the characteristics of fungi?
Heterotrophic, eukarotic, saprobes.
What is a saprobe?
An organism that absorbs food from decaying matter.
How do fungi eat?
By releasing digestive enzymes into their environment that break down the decaying matter. Then they absorb the digested food through their cell wall.
How are fungi different than slime moulds?
Fungi absorb through endocytosis.
What are the bodies of fungi made of?
Filaments called hyphae. They grow into a tangled mess of filaments called mycelium.
What is a mycelium?
A network of hyphae.
What are the cell walls of fungi made of?
Chitin. (Not cellulose).
How do most fungi reproduce?
Sexually and asexually with spores.