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Flashcards in Lab 1 Deck (11):

Under what conditions could asexual reproduction be advantageous?

Low population, instant large food supply


Binary fission

When organisms that lack an organized nucleus and divide primarily by a simple splitting of one bacterium into two parts.


Pure culture

Separates a mixture of bacteria. This is done by using a streak plate technique.


Streak-plate technique

A dilution method used for rapid and qualitative isolation of bacteria. Involves spreading a loopful of a culture of mixed bacteria over the surface of an agar plate in a series of streaks that are increasingly more dilute until the last streak results in individual colonies of a pure culture (single species of bacterium). An effective method for isolating discrete bacterial types for study.


The rapid rate of fission by bacteria can be controlled through the use of...



What is the purpose of the control section containing a plain paper disc?

Proving that it is not the paper reducing bacterial growth.


Bacterial shapes

Coccus: round
Bacillus: rod
Spirillum: corkscrew


Digestion in the hydra occurs inside the "tube" in the central (gastrovascular) cavity. Are the gastrovascular cavities of the adult hydra and its bud separate or continuous?



How does the bud apparently obtain food for growth until it is large enough to catch its own?

Connected gastrovascular cavity


Yeast have been stimulated to grow by putting them in water with a good size pinch of sugar. Why sugar?

Used for fermentation as a source of energy.


Asexual spores

Spores are extremely small and light, and are found nearly everywhere. The black color of the mold is caused by the spores.