5 - Protists Flashcards
What are the four eukaryote supergroups
Excavata, SAR, archaeplastida and unikonta
What are photoautotrophic protists and what are they called
Protists that contain plastids which allow them to use light to produce their own sugars. They are termed algae.
What are heterotrophic protists and what are they called?
Protists that feed on bacteria, fungi and other protists. They are called Protozoa
What are mixotrophic protists?
Protists that can carry out photoautotrophy and heterotrophy
Are protists eukaryotic or prokaryotic?
Eukaryotic
How are big are protists?
Between 0.005mm (5um) and 5mm
How does the a sexual reproduction of bacteria and protists differ?
Bacteria: split by binary fission, quicker doubling time and completely identical daughter cells
Protists: split by mitosis, slower doubling time and genetically identical but vary in other components
What are some advantages of cysts?
They can survive for 20 years, they can easily be dispersed and transmitted, they are resistant to disinfectants, heat drying and radiation
How is a cell wall of a protist different to that of a bacteria
Not all protists have cell walls but those that do have a very different structure (e.g. no peptiglycan and made of cellulose or silica)
What is a contractile vacuole?
a structure that collects the extra water and then expels it from the cell (in Protozoa without a cell wall)
Under what temperature can protists grow and how is this different to bacteria?
Protists can not grow at temperatures above 60 degrees, where as some bacteria/Archea (hyperthermophiles) can
What type of aerobes are protists?
They are either obligate aerobes or obligate anaerobes
What organelle do obligate anaerobes use to produce ATP?
Hydrogenosomes
How do heterotrophs eat their food?
They absorb a bacteria into a phagosome which combines with a lysosome which releases enzymes which break up the prey. The debris is excreated
What is organellar mixotrophy?
When a protists eats an algal cell but don’t digest the plastics which can then fix CO2. The cell has to keep eating the algae as the plastids are not able to reproduce in cell, so they need to be replenished when they die
What is cellular mixotrophy?
When a protists eats an algal cell and the algal cell remains in the cell and fixes carbon dioxide. The algal cells can reproduce so don’t need to be replenished
What are algae that can eat?
Protists that can eat but also have their own plastids
What are the main ways that a protist can move?
Using flagella, using cilia or via cytoplasmic streaming.
What are some similarities between protists and bacteria?
- both carry out a-sexual reproduction
- same population growth curve
- some protists (such as algae) have cell walls
What is the endosymbiont theory?
Theory that mitochondria and plastids were originally prokaryotes absorbed by ancestral eukaryotes
Which type of protists are algae that eat?
Flagellates
