Which of the following features is not a characteristic of $Protochordata$?

$(i)$ To which division of Plantae do algae belong? Write one characteristic of the division. Give two examples.
$(ii)$ Name the group:
$(a)$ Which includes unicellular eukaryotic organisms.
$(b)$ In which the mode of nutrition is saprophytic.
$(c)$ In which seeds are not enclosed in fruit.
$(iii)$ Classify flowering plants on the basis of the number of cotyledons present in the seed.

Which of the following is not an Annelid?

Fill in the blanks:
$(a)$ Fungi shows .............. mode of nutrition.
$(b)$ Cell wall of fungi is made up of ..............
$(c)$ Association between blue-green algae and fungi is called as ..............
$(d)$ Chemical nature of chitin is ..............
$(e)$ .............. has the smallest number of organisms with the maximum number of similar characters.
$(f)$ Plants without well-differentiated stem,root,and leaf are kept in ..............
$(g)$ .............. are called as amphibians of the plant kingdom.

State reasons for the following:
$(a)$ Bryophytes are called amphibians of the plant kingdom.
$(b)$ Gymnosperms are called so (naked-seeded plants).
$(c)$ Birds have wings and feathers.

Elephantiasis is caused by