Pollen grains can be stored for several years in liquid nitrogen having a temperature of
–120°C
–80°C
–160°C
–196°C
Which of the following has proved helpful in preserving pollen as fossils?
Pollenkitt
Cellulosic intine
Sporopollenin
Oil content
With respect to angiosperms, identify the incorrect pair from the following
antipodal - 2n
Vegetative all of male gametophyte - n
Primary endosperm nucleus-3n
Cell of nucellus of ovule -2n
Which one of the following statements is correct?
Hard outer of pollen is called intine
Sporogenous tissue is haploid
ENdothelium produces the microspores
Tapetum nourishes the developing pollen
When pollen tube enters through micropyle, the process is called
Porogamy
Chalazogamy
Mesogarny
Apogamy
Outer wall of pollen grain is made up of
Cellulose
Sporopollenin
Pectocellulose
Lignin
B.
Sporopollenin
A pollen grain contains two-layered cell wall, the outer exine and inner intine. Sporopollenin is found in the exine of pollen grains, which is the most resistant biological material known, of microbial and chemical decomposition. Due to this, pollen grains are well preserved during fossilization. Intine of pollen grain is made up of pectocellulose.
Which of the following floral parts forms pericarp after fertilization?
Nucellus
Outer integument
Ovary wall
Inner integument