Practical #2 - Bacteria and Protists

Question 1

List the 4 organisms in Domain Bacteria

Answer 1

• Prokaryotic Organisms
  
  • Proteobacteria
  • Gram-positive Bacteria
  • Spirochetes
  • Cyanobacteria

Question 2

List the organisms in Domain Eukarya

Kingdom Protista

Answer 2

• Phylum Dinoflagellata (dinoflagellates)
• Phylum Bacillariophyta (Diatoms)
• Phylum Chlorophyta (Green algae)
• Phylum Phaeophyta (kelps or seaweeds, brown algae)
• Phylum Euglenophyta (euglenoids)
• Phylum Rhizopoda (the ameobas)
• Phylum Kinetoplastida (The trypanosomes)
• Phylum Apicomplexa (Apicomplexans)
• Phylum Ciliata (ciliates)

Question 3

Domain Archaea

Answer 3

• Extemophiles
  
  • High temperatures (thermophiles)
  • Saltiness (Halophile)

Question 4

Different Bacteria Shapes

Answer 4

• Bacillus/Bacilli - elongated Rods
• Coccus/Cocci - circular
• Spirillum - spiral
• Strept - long chain
• Staphylo - clusters
• Diplo - connected pair

Question 5

Proteobacteria

Answer 5

• Mostly gram-negative
• Ex: Escherichia coli - E.Coli

Question 6

Gram-Positive Bacteria

Answer 6

• Produce many common antibiotics (Streptomyces
• Also can be pathogenic
• Looked like streptobaccili cells

Question 7

Spiral Shaped Bacteria (Spirochets)

Answer 7

• Helical or spiral shape
• Ex: Treponema
  
  • bacteria that causes syphillis

Question 8

Cyanobacteria

Answer 8

• Also called - “Blue-Green bacteria”
• Autotrophic
  
  • undergo photosynthesis (maybe not in chloroplasts though)
  • Contain Chlorophyll a
• Marine and Freshwater and moist soils
• Perform Nitrogen fixation within the heterocysts
  
  • give them the upper hand against other algae
• Ex: Anabaena

Question 9

Why are heterocyst walls thicker in cyanobacteria

Answer 9

To keep the nitrogen fixation away from the oxygen rich surroundings

Question 10

Why do Gram (+) bacteria and Gram (-) appear in different colors after a Gram stain?

Answer 10

• Gram (+) bacteria have a lare amount of peptidoglycan in their cell walls which can trap the purple dye.
• Gram (-) bacteria have little peptidoglycan. They do have an outer membrane, but this outer membrane does not prevent the alcohol from washing away the dye

Question 11

What are some quick facts about Protists?

Answer 11

• Kingdom Protista
• Unicellular Eukaryotes
• Most are aquatic
• Have nucleus and membrane bound organelles
• Mitosis and meiosis
• Sexual and asexual reproduction

Question 12

Dinoflagellates

Answer 12

• Unicellular Protists
• Marine and Freshwater
• Cell wall is made of overlapping cellulose
• Pair of flagella
• Cause Red Tide
• Mixotrophic
• Phylum Dinoflagellata

Question 13

Diatoms

Answer 13

• Phylum Bacillariophyta
• algae found in marine and freshwater
• Possess Chlorophyll a and Xanthophyll
  
  • Makes them the “Golden-brown algae”
• Hard outer cell wall made of silicon dioxide and calcium carbonates
• Look like a little disk/petri dish

Question 14

Green Algae

Answer 14

• Phylum Chlorophyta​
• Contain chlorophylls a and b
• Most live in freshwater
• Ex: Volvox
  
  • ​thousands of haploid, biflagellated cell with cytoplasmic connections to adjacent cells
  • Capable of sexual and asexual reproduction
  • diploid zygote is called zygospore

Question 15

Spirogyra (Green algae) and Conjugation

Answer 15

• Spirogyra undergoes sexual reproduction using conjugation
  
  • ​Two Haploid filaments line up next to each other (+ and -) and connect
  • THe connection is called a conjugation tube
• Content of (-) travel through the tube and fuse with (+)
• Zygote (2n) forms a zygospore
• Meiosis occufrs in zygospore but 1/4 nuclei actually germinates

Question 16

The Kelps

Answer 16

• Phylum Phaeophyta (brown algae)
• multicellular and autotrophic
• Live in shallow marine habitats
• Structure
  
  • Holdfasts - hold the protist in place
  • Stipe - stem
  • Blades - leafs
  • Float - air bladder helps hold blades close to surface for photsynthesis

Question 17

The Euglenoids

Answer 17

• Phylum Euglenophyta
• Usually possess 2 flagella
• Produce a unique starch - paramylon
• Have a stigma (eyespot) next to the base of the anterior flagella.
• Photosynthetic but can prey on small organism is necessary (mixotroph)

Question 18

Amoebas

Answer 18

• Phylum Rhizopoda
• Move using a pseudopodia, and for capturing food
• Found in freshwater and marine
• Free-living species are predators or scavengers

Question 19

What is a contractile vacuole?

Answer 19

• used to expel excess water from the freshwater species

Question 20

Trypanosoma

Answer 20

• Phylum Kinetoplastida or the flagellates
• Have one or more flagella
• Flagellum arises from the centriole (kinetosome) located at the anterior end
• kinetoplast is found near the kinetosome
• Transmits sleeping sickness from one animal to another by the bite of the tsetse fly (Glossina)

Question 21

Apicomplexa

Answer 21

• Phylum Apicomplexa
• All have an apical complex
  
  • group of organelles used to penetrate host cells
• All are parasites - several Plasmodium cause Malaria
  
  • ​Intracellular parasite
  • Look at the cycle on pg 11-21

Question 22

Paramecium

Answer 22

• Phylum Ciliata
• Move by ciliary action
  
  • cilia beat in coordinated fashin prepelling the organism
• Pellicle
  
  • ​Rigid outer covering outside of the cell membrane
• Micronuclei
  
  • ​Involved in sexual reproduction and conjugation
• Macronuclei
  
  • ​Involved in asexual reproduction and daily activity of the cell

Question 23

What is Fission and which protists use it?

Answer 23

• Asexcual reproduction used by Paramecium, Amoeba, Trypanosoma, Plasmodium
• Also called, binary Fission, where the nucleus undergoes mitosis and the cell subsequetnly divides into two by cytokinesis

Question 24

What is conjugation?

Answer 24

• One form of sexual reproduction
  
  • Common in ciliates
• 2 protozoans exchange genetic material, in a way that is similar to the fusion of 2 gametes
  
  • Fuse at the oral groove
  • the 2 cells exchange haploid micronuclei.
  • The 2 cells separate and go through some cell divsion to creat daughter cells