True or false a positive feedback mechanism results in amplification of the reaction

An example of a trait that would be considered acquired and inherited is a. a cleft chin b. muscle tone c. scar tissue d. freckled skin

Look at the photo of the leaf, which term best describes this leaf ? a-simple.b-parallel.c-lobed.d-tooth.

Ihave no idea how to solve these. plus there's another question that is 2) a 10 kilogram meteorite is collected in space and brought back to earth. it is composed of 1.25 kg of uranium-238 and 8.75 kg of lead-206. how many u-238 half lives have passed? what is the approximate age of the meteorite?