The 'Origin of Species' was written by:

Mention the problem which is associated with using local names of organisms. How was this resolved? Name the scientist who introduced the above solution.

Identify the animal and plant groups having:
$(a)$ Animals without tissues,body bearing pores.
$(b)$ Plant body differentiated into roots,stems and leaves but do not produce seeds.
$(c)$ Body dorsoventrally flattened without coelom.
$(d)$ Segmented worms with true body cavity with extensive organ differentiation.

State the phylum to which liver fluke and Planaria belong.

Why are bryophytes called the amphibians of the plant kingdom?

Give reasons for the following:
$(a)$ Echidna and Platypus lay eggs but are considered as mammals.
$(b)$ Birds have pneumatic bones.