Under what circumstance might slow-growing mycobacteria appear to produce colonies in a few days?
a. When the inoculum is too heavy
b. When subcultured to an enriched medium
c. When incubated at slightly warmer tem-peratures
d. When kept in the light
A
The rate of growth is an important criterion for determining the initial category of an isolate. The dilution of the organism used to assess the growth rate is critical. Slow-growing mycobacteria appear to produce colonies in less than 7 days if the inoculum is too heavy. Rapid-growers usually produce colonies within 3 to 4 days after subculture. Even a rapid-grower, however, may take longer than 7 days to produce colonies initially because of the inhibition by a harsh decon-taminating procedure. Therefore the subculture must determine the growth rate and pigment production.
You might also like to view...
Movement of cellular material from the endoplasmic reticulum to the outside of the cell is an example of:
A. exocytosis. B. endocytosis. C. transcytosis. D. phagocytosis.
What is the genetic makeup of dikaryotic nuclei?
a. 3n b. n c. n+n d. n+n+n e. 2n
Unsaturated tails tend to __________ at the sites of
their double bonds. a. dissolve b. kink or bend c. separate d. react with ions e. do none of these
Non disjunction:
a. is the cause of sex determination in birds and mammals. b. is the exchange of genetic material between the chromatids from homologous chromosomes. c. is the unequal division of the genetic material during cell division. d. is the division of cytoplasmic constituents. e. occurs during mitosis but not meiosis.