20 REVIEW QUESTIONS 1. What are the Masti distinguishing characteristics of the

ID: 272211 • Letter: 2

Question

20 REVIEW QUESTIONS 1. What are the Masti distinguishing characteristics of the free-living mem bers of Sarcodina. gophora, and Ciliophora? Chih: movemen 2. Identify and give the function of the following: b. Contractile vacuole: c. Eye spot: d. Micronucleus: e. Pellicle: f. Oral groove: 3. People with AIDS are vulnerable to pneumonia caused by the protozoan Pneumocys tis carinii. This organism is known to be a member of the normal flora in most humans. Why then are these individuals so susceptible to this generally rare form of pneumonia? Free-Living Protozoa

Explanation / Answer

Name of species

Distinguishing feature

Sarcodina

Presence of pseudopodia for locomotion, and also shows presence of ectoplasm and nucleus.

Mastigophora

Shows presence of flagella for locomotion. Presence of mouth, eyespot, and nucleus.

Ciliophora

Presence of Cilia for locomotion. Also presence of oral groove and food vacuoles.

Appendage

Function

Pseudopods

Locomotion and the capturing of prey.

Contractile vacuoles

Pump water out of the cell through osmoregulation,
Regulation of osmotic pressure.

Eye spot

Detection of light in euglena

Micronucleus

Helps in reproduction

Pellicle

Covers and protects cell membrane in protozoa

Oral groove

Gathering of food and water with the help of ciliary motions.

3. People with AIDS have a severely compromised immune system (their CD4 cell count falls below 200/ul). This paves the way for opportunistic infections like P.carinii, which leads to pneumonia in people with AIDS.