A radioactive material has a half-life of 30 days. You begin with 4 grams of radioactive material. a. How much of the original is left unchanged after 90 days? b. After 120 days?

you and your brother should be dizygotic twins (fraternal) twins since identical twins can only be one gender: boy and boy   or   girl and girl.

this protocol provides a detailed procedure for nucleoprotein extraction from cultured cells and tissues in an efficient manner.

succession returns a disturbed

ecosystem to a more stable state. this is also classified into two (2) types:

primary succession and secondary succession. the primary succession arises when

a new land is transformed and a bare rock has been exposed providing an environment

that can be occupied for the first time. while, secondary succession occurs

when a previously occupied environment was disturbed that kills much of all its

community

explanation: