For a certain insecticide, the LD-50 dosage level for rats is determined to be 250 milligrams per kilogram of body mass. On the basis of this information, which of the following is the best prediction regarding the consequences of receiving this dosage of the insecticide?
Five hundred out of every one thousand rats would die

500 out of every 1000 rats would die

Explanation:

Given LD (Lethal dose) = 50

This is the amount required to kill 50% of a test population

To get the whole test population,

Therefore 50/100= 250

That is 50 to 100

250 to x

Cross multiply

(250 × 100)/50

=500 (that is 50% of the population)

The whole population will be 500 × 2=1000

his research revealed two genetically different groups of prokaryotes, which justified splitting kingdom monera into two kingdoms. the genetic and cellular differences were so great, that these two kingdoms were eventually placed into different domains in the current three-domain system.