Star-shaped crystals found in $Dioscorea$ are known as:

Read the following four statements $(A-D)$:
$(A)$ Both photophosphorylation and oxidative phosphorylation involve uphill transport of protons across the membrane.
$(B)$ In dicot stems,a new cambium originates from cells of pericycle at the time of secondary growth.
$(C)$ Stamens in flowers of Gloriosa and Petunia are polyandrous.
$(D)$ Symbiotic nitrogen fixers occur in free-living state also in soil.
How many of the above statements are right?

Write the precise function of:
$(a)$ Sieve tube
$(b)$ Interfascicular cambium
$(c)$ Collenchyma
$(d)$ Aerenchyma

$T.S.$ of a dicot leaf is given below. Certain parts have been indicated by alphabets. Choose the correct option.

In which plant group is the structure shown below found?

Distinguish between the following: Protoxylem and metaxylem.