exercise 5: the protists

Question 1

plasmodium

Answer 1

• heterotrophic
• mosquitos -> malaria

Question 2

trypanosoma

Answer 2

• heterotrophic
• flagellated protist that lives in human blood plasma
• from flies

Question 3

saprolegnia

Answer 3

• heterotrophic
• water molds= diploid
• fungi= haploid
• cell walls made of cellulose
• during sexual reproduction, spherical enlargements called oogonia form at the tips of some hyphae (filaments) and produce eggs
• antheridia (sperm) got on other tips of hyphae
• asexual reproduction-> zoospores

Question 4

foraminifera

Answer 4

• heterotrophic
• “test”= small shell
• pseudopods extend through pores in the shells and are used for feedings and movement

Question 5

paramecium

Answer 5

• heterotrophic
• glide smoothly through the water by the beating of their cilia
• beating of cilia long the oral groove sweeps food particles into the gullet –> food vacuoles form
• 2 nuclei: macronucleus (polyploid, many copies of the organism’s genome), micronucleus (only involved in sexual reproduction)

Question 6

amoeba

Answer 6

-heterotrophic
- single-celled freshwater organisms
- feed on bacteria, algae, and detritus (dead organisms)
- change shape constantly-> form temporary pseudopodia
- flexible plasma membrane -> how pseudopodia are formed

Question 7

pellicle

Answer 7

a system of protein strips lying just under the cell membrane, associated with the cytoskeleton

Question 8

ceonocytic cells

Answer 8

no cross walls or cross cell membranes

Question 9

euglena

Answer 9

• autotrophic
• pull themselves through water using flagella
• body can stretch and contract because of pellicle
• most are green
• red photosensitive eyespot near feeding grove
• mixotrophs
• contractile vacuoles

Question 10

volvox

Answer 10

• autotrophic
• vegetative and daughter cells
• hollow spheres
• both asexual and sexual reproduction

Question 11

diatoms

Answer 11

• autotrophic
• unicellular,
  earth’s most primary producers
• yellow-brown pigment + chlorophyll
• cell walls of silica
• only occur in water that is well mixed

Question 12

heterotrophic protists

Answer 12

amoeba (live), amoeba (preserved), paramecium, foraminifera, saprolegnia, trypanosoma

Question 13

autotrophic protists

Answer 13

diatoms, volvox, euglena

Question 14

phytoplankton

Answer 14

unicellular, get their nutrients (nitrogen and phosphorus) from the ocean depths, base of the food chain, responsible for half of the oxygen gas in the atmosphere

Question 15

autotrophs

Answer 15

organisms that produce their own food

Question 16

contractile vacuoles

Answer 16

collect excess water from the cytosol and pump it outside

Question 17

freshwater environment is ______ to protist cytoplasm so water continuously ______ through osmosis

Answer 17

hypotonic, enters

Question 18

pseudopodia

Answer 18

long extensions that emerge from holes and capture food floating by

Question 19

colony

Answer 19

group of identical cells living attached to one another

Question 20

what are the properties of protists?

Answer 20

-eukaryotes that are not plants, animals, or fungi
- extremely diverse (heterotrophic, autotrophic, parasitic, mixotrophic)
- unicellular, multicellular, ceonocytic