Flashcards in Bio Unit Test 1 Deck (119)
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?
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.
Explain how ciliates eat.
1. Beat cilia to bring food into their oral groove.
2. The membrane pinches off and forms a food vacuole.
3. The food vacuole travels into the cytoplasm.
4. The food vacuole joins with a lysosome that breaks down the food.
5. 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?
1. 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?
1. Spend part of their life cycle within human red blood cells.
2. Red blood cell bursts open.
3. 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?