Differentiation in segmental fashion occurs in

$(i)$ 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 one is the most striking or common character of the vertebrates?

An animal is dorsoventrally flattened,has three embryonic germ layers,and is acoelomate. Which phylum does it belong to? What are they commonly called? Give one example.

Label $a, b, c$ and $d$ given in the figure. Give the function of $(b)$.

$(a)$ What is the significance of binomial nomenclature?
$(b)$ Who introduced the system of scientific naming?
$(c)$ Write any two conventions followed while writing the scientific names.