A microbial ecologist wants to study a bacterium that is adapted to growth in lake water containing very low nutrient concentrations. Assuming that a suitable growth medium is available for this organism, which type of culture would be best to use for growing this organism in the lab?
A) this organism cannot be grown in the lab.
B) a batch culture using a low-nutrient medium
C) on Petri plates containing a low-nutrient medium
D) a chemostat using a low-nutrient medium

D) a chemostat using a low-nutrient medium

Explanation:

A chemostat is a bioreactor in which a constant chemical environment is maintained. In the bioreactor the fresh medium is added, whereas the culture liquid, left out nutrients, microorganisms and metabolic end products are removed from the medium at the same rate to keep the volume of the culture constant.

The volume and concentration of the nutrient medium can be maintained in the chemostat bioreactor.

According to the given situation, the bacteria can be cultured in low-nutrient growth medium that is the lake water to observe its adaptation under the low-nutrient concentration.

hormones in blood stream

image: dtc.ucsf.edu

endocrine glands secrete hormones into the blood stream near them; the hormones then travel in our bloodstream until it reaches its destination, called a target cell, in distance parts of the body. in the target tissue, hormones lock onto the target’s plasma membrane, called the receptor site.