When a scientist takes a small part of a habitat and counts the population, then applies it to the entire habitat, he/she is practicing
indirect observation
direct observation
mark and recapture
sampling

the truman doctrine was an american foreign policy whose stated purpose was to counter soviet geopolitical expansion during the cold war. it was announced to congress by president harry s. truman on march 12, 1947, and further developed on july 12, 1948, when he pledged to contain threats to greece and turkey.

this is true, assuming that the allele is completely recessive and incomplete dominance is not a factor.