Answer:
The correct answer is B. All organisms would appear purple (gram-positive).
Explanation:
Gram staining is done to differentiate between gram positive and gram negative bacteria. Gram positive bacterial cell wall is made up of peptidoglycan which dehydrates and shrinks after decolorizing step and large crystal violet and iodine complex do not comes out making them purple in this process.
But in gram negative bacteria the cell wall is made up of lipids in which the crystal violet-iodine complex comes out due to the degradation of lipid by decolorizer.
So when the student forgot to decolorize bacterial sample crystal violet do not comes out from gram negative cell wall making them purple like gram positive cells. So all organism will appear purple.
Answer:
Scientists define density as the mass of a substance per unit volume. The word “per”
signals that thinking about density requires thinking about a relationship. It is the relation
between the mass (or weight) of one unit of a material and the volume of that one unit.
Density cannot be directly perceived or measured. It must be inferred from the
relationship of the mass and volume. However, it can be determined by calculation
which is how many schools teach it. To calculate density, you first measure the weight
and volume of an object precisely, then you divide the mass by the volume (i.e. d=m/v,
density equals mass divided by volume). So for example, the density of water is 1 gram
per cubic centimeter because a volume of 1 cubic centimeter of water has a mass of 1
gram. A substance which has a mass of greater than one gram per cubic centimeter
has a density greater than 1.0 gram per cubic centimeter; a substance which has a
mass of less than one gram per cubic centimeter has a density of less than 1.0 gram
per cubic centimeter.
Explanation:
This is true that the pressure in the mesosphere is so low that a person could not be in this layer without a spacesuit.
The mesosphere is the region of the earth's atmosphere which is above the stratosphere and below the thermosphere. It has a very low temperature and pressure. The top of the mesosphere is the coldest part of Earth's atmosphere.