$(i)$ 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.

(N/A) $(i)$ Algae belong to the division Thallophyta.
Characteristic: The plant body is not differentiated into roots,stems,and leaves (thallus-like body).
Examples: $Spirogyra$,$Chara$ (or $Ulothrix$,$Cladophora$).
$(ii)$ $(a)$ Protista,$(b)$ Fungi,$(c)$ Gymnosperms.
$(iii)$ Flowering plants (Angiosperms) are classified based on the number of cotyledons as:
$1$. Monocots: Seeds contain only $1$ cotyledon.
$2$. Dicots: Seeds contain $2$ cotyledons.