Why are angiosperms so called? In which structures do the seeds develop? Why are cotyledons considered an important part of seed?

$(i)$ Draw a neat diagram of Hydra.
$(ii)$ Label mesoglea and gastrovascular cavity.
$(iii)$ Name the group of animals it belongs to.
$(iv)$ Name one species of this group that lives in colonies.

Why are bats not placed in birds?

State reasons for the following:
$(a)$ Mammals have mammary glands.
$(b)$ Annelids have a true body cavity.
$(c)$ Fish possess gills.

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.

In which group of animals,the coelom is filled with blood?