<span>d- They take in oxygen gas dissolved in the water through their gills.
</span>
Answer:
a. When the foot rolls OUTWARD
Explanation: is correct
Answer:
Option-A
Explanation:
Penicillin is an antibiotic drug that is derived from the fungal species of Penicillium molds especially the<em> Penicillium notatum</em>. The penicillin acts by disrupting the formation of the cell wall and thus prevents the growth of the bacteria.
The discovery of penicillin was accidental when he was studying the petridish of staphylococcus and he found that due to avoidance while the experiment, molds grew in the petridish. The area around the mold was clear and clear rings without the bacteria were easily observed. This lead to the discovery of the penicillin compound.
Thus, Option-A is the correct answer.
Answer:
The hardness rating is 4.
Explanation:
Calcite sits at a hardness rating of 3 and is very easily scratched with a knife and/copper coin. This is where most Marbles, limestones, travertines, rate.
Meanwhile, Fluorite sits at hardness 4 and can be scratched by a knife.
