Answer:
In acid-fast staining, carbon fuchsin is used as a primary stain which dissolves the mycolic acid present in the cell wall of <em>Mycobacterium smegmatis </em>and penetrates through it which results in staining <em>Mycobacterium</em> red.
Staphylococcus aureus cell wall does not contain mycolic acid so carbon fuchsin does not penetrate its cell wall, therefore, it becomes colorless after destaining with acid alcohol.
After destaining step methylene blue is added to stain non-acid-fast bacteria blue. So if I mistakenly forgot to use methylene blue during the procedure <em>Mycobacterium smegmatis</em> will appear red due to carbon fuchsin present in their cell wall and S<em>taphylococcus aureus</em> will appear colorless because it is destained.
I think its if one parent has no alleles for the disease.
Sorry if this is wrong but a closed circulatory system is blood that is contained inside blood vessels, circulating unidirectionally (in one direction) from the heart around the systemic circulatory route, then returning to the heart again.
A phenotype is a physical characteristic which is visible. Hence when the resulting combinations have two dominant alleles or even one dominant allele, the dominant characteristic is exhibited. The recessive characteristic is exhibited only when both the alleles are recessive.
To find the ratio of phenotypes, we need to place the genotype of the father and mother in a grid form ( attached grid figure)
Here we have two Ff phenotypes which is dominant and two ff phenotypes which is recessive
Hence the ratio is 2:2 or 1:1