Your question is rather unclear but from what I can tell either there were not an even amount of Petri dishes or some of them were left open while others were not.
Yes this is true. The Punnett square can be used for such purposes
There are 4 granddaughter cells at the end of Meiosis, that might help you find your answer better without giving you a complete answer.
Compression and stretching are actually caused by the stress on the both.
Compression happens on the side of impact and Stretching happens ont he side opposite to that of the impact.
The correct answer is none of the above.
Bacterial cells can transfer genetic material through a process called bacterial conjugation. This process involves the direct physical contact of the bacterial cells and a horizontal gene transfer. The genes which are transferred are most of the times beneficial for the recipient, such as genes for antibiotic resistance.
In this example, bacterial cells cannot have physical contact, since they are separated by a glass filter. Therefore, the bacterial conjugation cannot happen. Given that no gene transfer can be achieved, the AY strain remains bio- trp- and is unable to grow on any medium that lacks bio or/and trp.
