The most resistant organic material known which makes up the outermost layer of pollen wall is
Pectin
Cellulose
Sporopollenin
Lignin
Sporopollenin $\rightarrow$ Caratenoid derivative
Which one of the following statements is wrong?
The thin and continuous wall layer of pollen is
Which of the following statements is correct?
What is correct for parthenium (Carrot grass)?
$(a)$ It came into India as a contaminant with imported wheat
$(b)$ It causes allergy
$(c)$ Asexual reproduction occurs in its flower
At the time of pollination, how many cells are formed in the pollen grains
