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Magazine Problem 229
Assertion: Angiosperm can colonize is other areas easily. Reason: Angiosperms have seeds and seeds have better adoptive strategies for dispersal to new habitats.
Problem 232
Assertion: Exine of pollen grain is discontinuous layer. Reason: Exine absent at germ pores.
Problem 233
Assertion: Pollen grains of some species can cause asthma. Reason: Pollen grains of some species are act as allergens.
Problem 234
Assertion: Pollen bank can be formed for crop breeding programmes. Reason: Pollen grain of many species can be stored for year in liquid nitrogen \(\left(-196^{\circ} \mathrm{C}\right)\)
Problem 235
Assertion: Wind pollinated plant have large feathery stigma. Reason: Feathery stigma easily traps air-borne pollen grains.
Problem 236
Assertion: Water pollinated species have mucilaginous covering on pollen grains. Reason: Mucilage covering protect pollen grain from wetting.
Problem 237
Assertion: Majority of flowering plant have bisexual flower still they show cross pollination. Reason: Continued self-pollination results in inbreeding depression.
Problem 239
Assertion: Artificial hybridisation requires emasculation in bisexual flower. Reason: Emasculation is removal another before their dehiscence so it prevent self pollination.
Problem 240
Assertion: The ploidy of primary endosperm nucleus (PEN) in angiosperm is \(3 \mathrm{n}\). Reason: PEN is formed by triple fusion.
Problem 241
Assertion: Endosperm development occurs before embryo development. Reason: Cells of endosperm are filled with reserve food material and act as source of nutrition for developing embryo.
