Protista

Question 0

Describe a protist?

Answer 0

Unicellular, have a nucleus so are eukaryotic, can only be seen via microscope, live in watery environment and live as individual cells eg. Amoeba, diatoms, euglena.
They can be multicellular eg. Slime molds or kelp

Question 1

What are Protista?

Answer 1

Algae- plant like protists
Protozoa - animal like protists
Slime and water molds- fungal like protists

Question 2

What are the characteristics of animal like protists (protozoans)?

Answer 2

Unicellular 
Require water
Most are heterotrophic
Some photosynthetic
Some are parasitic

Question 3

How do protozoans (animal) function?

Answer 3

They have food and waste vacuoles
Capable of movement
Respond to environment ( some have light sensitive eye spot)

Question 4

How do plant like protists survive?

Answer 4

Photosynthesis

They have no true roots, stems or leaves

Question 5

How do plant like protists survive?

Answer 5

Maintain homeostasis
Contractile vacuoles pump out excess water
Form protective cysts when food or water is scarce

Question 6

Describe fungi like protists?

Answer 6

Heterotrophic
Decomposers
No cell wall

Question 7

How do protists reproduce?

Answer 7

Asexual- binary fission 2 identical clones rapid reproduction rate
Sexual- produce gametes( advantage- genetic variation)
Sexual via conjugation- opposite mating strains pair and exchange Dna

Question 8

What size are protists?

Answer 8

Microscopic - unicellular
Colonies- loosely connected groups of cells
Multicellular - many cells eg. Brown algae

Question 9

Protists can be classified by the way in which they move. Describe these ways?

Answer 9

Ciliates- have cilia ( fine hairs)
Flagellates- have flagella
Amoebas - have pseudo podia
Sporozoans - don’t move

Question 10

Why are protists important?

Answer 10

Heterotrophic ( Protozoa) consume bacteria and other protists making components of aquatic and soil food webs
They recycle nutrients
Some cause disease- malaria, dysentery sleeping sickness

Question 11

How to protists interact?

Answer 11

They are free living or symbiotic

Symbiotic - mutualism to parasitism

Question 12

How are protozoan ( animal like protists) recognised?

Answer 12

Nucleus, lack cell wall, heterotroph, move on their own, gather microbes as food.
They digest food in stomach type compartments (vacuoles)
Give of nitrogen during digestion

Question 13

Name the 3 types of Protozoa?

Answer 13

Ciliates eg. Paramecium
Amoeba eg. Entamoeba histolytica ( causes dysentery )
Flagellates eg. Trapanosoma ( causes African sleeping sickness)

Question 14

Describe the characteristics of a ciliate?

Answer 14

Cilia for feeling and movement
Eat other Protozoa and bacteria- food swept into mouth moves to gullet where food vacuole is formed. Enzymes from cytoplasm digest food. Waste expelled from anal pore.
Locomotion- rotates along its long axis

Question 15

List the characteristics of the paramecium?

Answer 15

Most complex ciliate
Unicellular
Definite shape
Certain parts of the cytoplasm do different things

Question 16

Describe the structure of the paramecium?

Answer 16

Pellicle- tough outer wall
Oral groove
Gullet/ food vacuole/ contractile water vacuole 
2 nuclei
Reproduces binary fission/ conjugation

Question 17

What are the 2 types of amoeba?

Answer 17

Testate- shell like covering

Naked amoeba- no covering

Question 18

Liar the characteristics of an amoeba?

Answer 18

Cell memb/ no wall- live in water or moist places
Have pseudopod- extension of cell memb + cytoplasm ( used for sliding movement and to collect food by phagocytosis, no def shape)
Reproduce binary fission
Sensitive to light and chemicals

Question 19

List the characteristics of flagellates ( smallest of the animal protists)?

Answer 19

Have flagella for movement
Live in fresh water- can be parasites eg. African sleeping sickness
Live in animals
Can be symbiotic - 1 has benefit
Mutalistic - trichonympha digest cellulose in guts of termites

Question 20

What is African sleeping sickness?

Answer 20

Tsetse fly (vector) carries trypanosoma
55 million at risk 0.5 million infected
Causes fever, anaemia, parasite invades fluid around brain and spinal cord- loc then death
Drugs effective in early stages

Question 21

How are plant like protists classified?

Answer 21

By colour
Autotrophic- algae
Photosynthetic- kelp

Question 22

What are the 6 groups of plant like protists?

Answer 22

Euglenoids
Diatoms
Dinoflagellates
Red, green, brown algae

Question 23

Describe euglenoids?

Answer 23

Green- large amt chloroplasts
Unicellular
Live in fresh water
Autotrophs/ heterotrophs in absence of light
Flagella and eyespot sensitive to light

Question 24

Describe diatoms?

Answer 24

Unicellular Need sun for photosynthesis Live in upper 200m of ocean and fresh water Brittle shell walls made of silica and pectin Appearance- flying saucers, canoes,cigars

Question 25

Describe dinoflagellates?

Answer 25

Unicellular Strong cell walls 2 flagella spinning movement Photo and heterotrophic Asexual reproduction Colour pigment/ glow in dark bioluminescence

Question 26

What causes red tide?

Answer 26

Dinoflagellates- triggered by warm weather

Question 27

What can cause shell fish poisoning?

Answer 27

Dinoflagellate neurotoxins- concentration in bodies of fish and shell fish that eat algal cells

Question 28

Describe red algae?

Answer 28

``` Rhodophyta Multicellular Warm and cold water Absorb green violet and blue waves These light waves penetrate below 100m ```

Question 29

Describe green algae?

Answer 29

Most unicellular some multicellular Form colonies Live in fresh or salt water Close relationship with plants

Question 30

Describe brown algae?

Answer 30

Seaweed Contain brown orange yellow and green pigments Attach to rocks Have air bladders Found in cool salt water along rocky coasts

Question 31

Describe fungus like protists?

Answer 31

``` Heterotrophic Have cell walls Some have flagella Reproduce with spores Eg. Slime molds or downy molds ```