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

73.

Offsets are produced by

• Meiotic divisions

• Mitotic divisions

• Parthenogenesis

• Parthenocarpy

Winged pollen grains are present in

• Mustard

• Cycas

• Pinus

• Mango

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

Endosperm of gymnosperms is

• Haploid

• Tetraploid

• Diploid

• None of these

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

Which of the following floral parts forms pericarp after fertilization?

• Nucellus

• Outer integument

• Ovary wall

• Inner integument