18. <em>Penny</em>: Used to measure mineral toughness; <em>Cuprum</em> penny's toughness is 3.
<em>Hand Lens</em>: Could be used to measure the hardness of the mineral; the glass can be used as a scratch platform; it can also be used to test the luster of the mineral tile; the mineral is rubbed in the glass portion of the tile and a powdery strike of the stone is given to distinguish the colour of the rock.
<em>Geological hammer</em>: Used to break down the mineral to assess whether or not it has cleavage, and to detect fractures
<em>Pocketknife</em>: Used to define mineral tenacity; the tenacity of the mineral can be silky, malleable, sectile, elastic, or flexible.
17. Volcanoes are holes or cracks in the lava-flowing crust of the earth. They are normally placed on the borders of tectonic plates as they are created as the plates clash and create gaps. In other words, volcanoes located at convergent-plate boundaries.
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Answer:
Of the 92 natural elements, 25 are essential for life. Of these, there are six main elements that are the fundamental building blocks of life. They are, in order of least to most common: sulfur, phosphorous, oxygen, nitrogen, carbon, and hydrogen.
Explanation:
Answer:
The correct answer is B. The virus can infect the host.
Explanation:
- As the host and the virus both remain in the agar plate, the virus is capable of infecting the host cells.
- The host cell multiplies and grows by utilising the nutrient from the agar medium.
- After the virus particles infect the host, they replicate inside the host and produce new progeny virions which get released out of the host cell by killing it.
- The newly formed virions infect other host cells and the process continues.
- The killing of the host cells by the viruses result in the generation of clear zones on the agar plate which is also known as the zone of exclusion.
- In the zone of exclusion region, the host cells have been killed by the viruses.
Answer:
39
Explanation:
When u have 100 cells and most of them are resestant to drugs most people have 39 cells
rain/condensation/precipitation
something like that
