The yellow ring inside the bacterial cell represents the bacterial DNA. Why does this structure disappear by step 3(this is when replication of viral nucleic acid and protein and envelope.) of the lytic cycle?

When the virus injects it’s nucleic acid into the cell it uses the cell’s ribosomes to make virus proteins and those proteins are the main cause for the break up of the cell’s DNA.

the answer to your question is b

tsd is temerature dependent sex determination.

tsd: it is a type of environmental sex determination in which the temperature experienced during embryonic/ larval development (ambient temperature for development) determine the sex of the offspring.

crocodile displays the tsd where the ambient temperature of the developing egg determines the individual's sex. for example in the american alligator's eggs, incubation at 33 ºc produces mostly males, while incubation at 30 ºc produces mostly females. so if the american alligator's egg will get the ambient temperature (33 degree celcius)during embryonic development from egg, the offspring will be male and same for the female sex determination.