5 - Protists

Question 1

What are the four eukaryote supergroups

Answer 1

Excavata, SAR, archaeplastida and unikonta

Question 2

What are photoautotrophic protists and what are they called

Answer 2

Protists that contain plastids which allow them to use light to produce their own sugars. They are termed algae.

Question 3

What are heterotrophic protists and what are they called?

Answer 3

Protists that feed on bacteria, fungi and other protists. They are called Protozoa

Question 4

What are mixotrophic protists?

Answer 4

Protists that can carry out photoautotrophy and heterotrophy

Question 5

Are protists eukaryotic or prokaryotic?

Answer 5

Eukaryotic

Question 6

How are big are protists?

Answer 6

Between 0.005mm (5um) and 5mm

Question 7

How does the a sexual reproduction of bacteria and protists differ?

Answer 7

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

Question 8

What are some advantages of cysts?

Answer 8

They can survive for 20 years, they can easily be dispersed and transmitted, they are resistant to disinfectants, heat drying and radiation

Question 9

How is a cell wall of a protist different to that of a bacteria

Answer 9

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)

Question 10

What is a contractile vacuole?

Answer 10

a structure that collects the extra water and then expels it from the cell (in Protozoa without a cell wall)

Question 11

Under what temperature can protists grow and how is this different to bacteria?

Answer 11

Protists can not grow at temperatures above 60 degrees, where as some bacteria/Archea (hyperthermophiles) can

Question 12

What type of aerobes are protists?

Answer 12

They are either obligate aerobes or obligate anaerobes

Question 13

What organelle do obligate anaerobes use to produce ATP?

Answer 13

Hydrogenosomes

Question 14

How do heterotrophs eat their food?

Answer 14

They absorb a bacteria into a phagosome which combines with a lysosome which releases enzymes which break up the prey. The debris is excreated

Question 15

What is organellar mixotrophy?

Answer 15

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

Question 16

What is cellular mixotrophy?

Answer 16

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

Question 17

What are algae that can eat?

Answer 17

Protists that can eat but also have their own plastids

Question 18

What are the main ways that a protist can move?

Answer 18

Using flagella, using cilia or via cytoplasmic streaming.

Question 19

What are some similarities between protists and bacteria?

Answer 19

• both carry out a-sexual reproduction
• same population growth curve
• some protists (such as algae) have cell walls

Question 20

What is the endosymbiont theory?

Answer 20

Theory that mitochondria and plastids were originally prokaryotes absorbed by ancestral eukaryotes

Question 21

Which type of protists are algae that eat?

Answer 21

Flagellates