With a light microscope, observation of which of the following would allow discrimination between a prokaryote and a eukarkyote?
a. the cell membrane
b. a nucleus
c. flagella
d. a cell wall
Ans: b. a nucleus
You might also like to view...
Which of the following is a Gram-negative bacterium that acts as a predator on other Gram-negative bacteria, and might be used to control populations of Gram-negative human pathogens in locations such as poultry farms?
A. Salmonella enteritidis B. E. coli C. Vibrio choerae D. Bdellovibrio
All of the following are mechanisms of thermoregulation in ectothermic animals EXCEPT
A. countercurrent heat exchangers. B. changing the rate of heat production by muscular activity. C. changing the rate of heat loss by vasodilation and vasoconstriction. D. relocating to cool areas when too hot or warm areas when too cold. E. insulation in the form of feathers or fur.
Local and long-distance signals in cells will trigger
changes in a. metabolism. b. gene expression. c. growth. d. development. e. any of these.
How must spindle microtubules attach to chromosomes during prometaphase of meiosis I?
a. Microtubules attach at the centrosomes. b. Microtubules attach to the chiasma. c. Spindle microtubules from one pole attach to one kinetochore, and spindle microtubules from the other pole attach to the other kinetochore in a pair of sister chromatids, just like in mitosis. d. Spindle microtubules from one pole must attach to both kinetochores in a pair of sister chromatids. e. Microtubules attach using their minus (slow assembling) ends.