A trait that occurs in 900 individuals out of a total of 1,800 individuals occurs with a probability of

0.5

Explanation:

Number of people with traits = 900

Total number of individuals= 1800

To find the probability with regards to the question, we divide the number of individuals having the traits by the total population of individuals. This will be:

= 900 / 1800

= 0.5

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.

the real answer is b. scintillation counter