Reference no: EM132555496

1. What is the difference between a trophozoite and a cyst, and why is one generally more infective than the other?

2. A technician working for you in a microbial reference laboratory has examined a number of different samples and recorded his results. From his notes, identify the group or subgroup (be as specific as you can) represented by each description.

a. A freshwater sample containing a colonial algae, bright green in color with cell walls made of cellulose.

b. A blood sample in which the red blood cells have microbial inclusions. The sample belonged to a person who had recently returned from a mosquito-infested region of Africa.

c. A large organism (over 3 m), found on the beach, brown in color, which stores food as mannitol.

d. A water sample from a birdbath. The numerous small organisms seen are covered with fine hairs.

e. A marine sample containing a number of small organisms with nearly symmetrical shells. Further analysis indicates that the shells are made of silicon dioxide and that the organisms are rich in oil.

f. An organism possessing lobe-shaped pseudopods, isolated from the feces of a person recently deceased after a gastrointestinal illness.

g. A seawater sample sent to your lab from the Gulf Coast. The water has an orange tint to it, and organisms in  the jar have a pair of flagella and seem to rotate as they move through the water.

h. A pond water sample in which the flagellated organisms are marked by a single red spot at one end.