Unit 4 - Part 9 Protozoa Flashcards
What are the two main stages in the life cycle of cysts or occyst-forming protozoa?
- Trophozoites
2. Cysts or oocysts
What is the active feeding stage of protozoa?
Trophozoites
How do trophozoites reproduce?
Asexually by binary fission
True or False:
Cysts are metabolically active
False
- cysts are metabolically inactive
True or False:
Oocysts are the products of sexual reproduction
True
What three things can cysts AND oocysts do?
- Remain infective/infectious outside the hosts
- Survive the environment for a long time
- May be involved in reproduction
Describe the stages involved where a trophozoite forms into a cyst
- Trophozoite (active, feeding)
- Drying, lack of nutrients - cell rounds up, loses motility
- Early cyst wall formation
- Mature cyst (dormant, resting stage)
- Moisture, nutrients restored
- Cyst wall breaks open
- Trophozoite is reactivated
True or False:
Both simple and complex reproductive strategies are observed among protozoa
True
True or False:
Some protozoa only asexually reproduce while others only sexually reproduce
False
- some reproduce only asexually
- others reproduce BOTH sexually and asexually!
What are the two methods that protozoa can reproduce asexually?
- Binary fission
2. Multiple fission
What happens in binary fission?
A parent cell gives rise to TWO daughter cells
What happens in multiple fission (also called schizogony)?
A parent cell gives rise to multiple daughter cells
What are the 3 names for a parent cell?
- Schizont
- Meront
- Segmenter
What are the 4 different ways that a protozoa can undergo fission (what are the 4 types of fission)?
- Spherical fission
- Longitudinal fission
- Transverse fission
- Oblique fission
What occurs in sexual reproduction of protozoa?
Fusion of gametes or gametocytes to produce zygotes
What are the 5 stages of reproduction for malaria?
- Asexual phase (human is infected)
- Exoerythrocytic phase (in liver cells)
- Erythrocytic phase (in RBC)
- Gametocyte phase (in RBC)
- Sexual phase (in mosquito)
What is an example of a protozoan disease that involves mosquitos?
Malaria
What is the mode of transmission of malaria?
Female mosquitoes (Anopheles)