Answer:
Petri plates are incubated upside down to prevent contamination.
Explanation:
The plates are always incubated inverted or turned upside down on their covers during storage. This is done to prevent evaporation if plaque is stored for long periods, which can affect the growth efficiency of bacteria, or allow contamination by multiplying unwanted organisms such as mold.
Once the plaques have been filled with a damp suspension of bacteria, it should be allowed to evaporate shortly before overnight incubation. However, a moderate amount of moisture will still be present. If plaque is not inverted during incubation, bacteria will not be able to attach to the culture medium properly, which will either prevent them from growing and forming colonies properly or will encourage the growth of undesirable microorganisms.
Any of these results will invalidate the experiment. In addition, any condensation or moisture can cause streaking, which will make it difficult to select and analyze separate colonies. After bacteria form colonies, plaque is also stored upside down to maintain moisture levels.
The answer should be allele(s).
Alleles are alternative forms of genes. For example in eye color, there is brown eye allele that produces brown eyes or blue eye alleles that produces blue eyes.
However, note that there may be dominant or recessive alleles. Dominant alleles are always expressed, meanwhile, recessive allele is only expressed when there is no dominant allele existing.
An example is let say brown eye allele is dominant and blue eye allele is recessive. The eye gene is controlled by 2 alleles. If I had one brown eye allele and 1 blue, my eyes will be brown, because brown eye allele is dominant.
The percentage that the off spring will be deaf is 75%. Two punnet squares are needed each for kkMm and Kkmm individuals. In punnet square 1, half of the genotypes are Km and km while half are Mm and kk in punnet square 2. The two punnet squares are then combined to form a final one where a quarter of the offspring are deaf.
