Question

please solve "21" it is related to bio

Answer 1

there features were to light to take weight is of these dinosaur

Answer 2

a)  some dinosaurs had feathers but could not use it for flying since its main purpose was to provide insulation or protect from heat. it was not developed enough for flight
b)  inherited traits are those traits which can be passed on to the next generation 
     acquired traits are those traits that are acquired by the individual in his lifetime and cant be passed on to next gen
c) sex chromosome is the chromosome that determines the sex of the offspring

hope that helps