Biol 370 Exam 1 QUESTIONS WELL
ANSWERED
Koch's postulates: - correct answer ✔✔ 1) Microbe must be present in all disease cases, absent
from healthy animals
2) Isolate microbe, grow in pure culture
3) When microbe is Introduced into susceptible animal, same disease occurs
4) Re-isolate microbe, confirm it's the same strain
HIV is not proven to cause AIDS
Spontaneous generation - correct answer ✔✔ Hypothesis stating that life could arise from
nonliving matter. Disproved by Pasteur and Redi.
Gram staining - correct answer ✔✔ 1) flood heat fixed smear with crystal violet for 1 min
2) add iodine(mordant) to make CV-I complex for 3 min.
3-wash with alcohol to decolorize briefly. Gram + are purple, Gram - are colorless
4-Counterstain with safranin for 1 min. Gram + are purple, Gram - are red
Direction of flagella moving towards attractant - correct answer ✔✔ counterclockwise
Direction of flagella moving away from attractant - correct answer ✔✔ clockwise
Bacterial Shapes - correct answer ✔✔ Cocci
Bacilli
ANSWERED
Koch's postulates: - correct answer ✔✔ 1) Microbe must be present in all disease cases, absent
from healthy animals
2) Isolate microbe, grow in pure culture
3) When microbe is Introduced into susceptible animal, same disease occurs
4) Re-isolate microbe, confirm it's the same strain
HIV is not proven to cause AIDS
Spontaneous generation - correct answer ✔✔ Hypothesis stating that life could arise from
nonliving matter. Disproved by Pasteur and Redi.
Gram staining - correct answer ✔✔ 1) flood heat fixed smear with crystal violet for 1 min
2) add iodine(mordant) to make CV-I complex for 3 min.
3-wash with alcohol to decolorize briefly. Gram + are purple, Gram - are colorless
4-Counterstain with safranin for 1 min. Gram + are purple, Gram - are red
Direction of flagella moving towards attractant - correct answer ✔✔ counterclockwise
Direction of flagella moving away from attractant - correct answer ✔✔ clockwise
Bacterial Shapes - correct answer ✔✔ Cocci
Bacilli
