An example of a seed with endosperm, perisperm and caruncle is 

  • Cotton

  • coffee

  • lily

  • lily


D.

lily

The seeds of castor (Ricinus communis, family -Euphorbiaceae) are endospermic dicot seeds. They possess  endosperm which acts at the food storgage tissue of seed. They also possess perisperm and cruncle.

527 Views

Synapsis occurs between 

  • a male and female gamete

  • mRNA and ribosomes

  • spindle fibres and centromere

  • spindle fibres and centromere


D.

spindle fibres and centromere

In zygotene of prophase-I, homologous chromosomes pair up. This process is called synapsis. One chromosome of the pair is from the male parent and one from the female parent.

362 Views

Cotyledons and testa are edible parts of 

  • groundnut and pomegranate

  • walnut and tamarind

  • french bean and coconut

  • french bean and coconut


A.

groundnut and pomegranate

Cotyledons and testa are edible parts of groundnut and pomegranate respectively.
The edible part of walnut is cotyledon; tamarind-mesocarp; french bean seeds, coconut-endosperm, testa, cotyledons and embryo, cashew nut-cotyledons and fleshy pedicles and of litchi is fleshy aril.

514 Views

Advertisement

Transfer of pollen grains from the anther to the stigma of another flower of the same plant is called

  • xenogamy

  • geitonogamy

  • karyogamy

  • karyogamy


B.

geitonogamy

Geitonogamy (Greek geiton = neighbour and gameiu = to marry) involves the transfer of pollen grains from a male flower to the stigma of another female flower origination on the same plant. Thus, geitonogamy operates only in monoecious plants i.e plants having male and female flowers on different places but on the same plant, e.g maize (zea mays). In animal pollinated system, thisis accomplished by pollinator visiting multiple flowers on the same plant. It is also possible within species that are wind pollinated.

324 Views

Advertisement

Wind pollinated flowers are

  • small, brightly coloured, producing large number of pollen grains

  • small, producing large number of dry pollen grains

  • large, producing abundant nectar and pollen

  • large, producing abundant nectar and pollen


B.

small, producing large number of dry pollen grains

Pollination taking place by means of wind is known as anemophily, eg, Zea mays, Cannabis Pinus, etc. Some features of wind-pollinated flowers are - 
i) Non -essential Whorls such as calyx, corolla and bracts, bracteoles are not showy.
ii) The perianth lobes are undeveloped or reduced and sometimes absent.
iii) Flowers are devoid of scent and nectars. 
iv) Plants produce a very large quantity of dusty pollen grains.
v) Pollen grains are dry, very small sized, non-sticky and unwettable

These features are helpful for the individuality of pollen grains.

386 Views

Advertisement