Embryo sacs of some apomictic species appear normal but contain diploid cells. Suggest a suitable explanation for the condition.
Instead of normal sexual reproduction a sexual reproduction takes place without fertilisation is called apomixis. eg. production of buds than flowers and origin in of plant inplace of seed. The organisms produced by Apomictic reproduction resemble their parent plant genetically. In flowering plants in a limited way means angiosperm means asexual reproduction by seeds. In some plants this is very common e.g. Esteraceac, poaceac. In some species without meiosis deploid egg cell is produced and develops into embryo without fertilization.
In some plants e.g. chebari, citrus. This is very common. e.g. Esteraceae, poaceae. In some species diploid egg cell is produced and without egg cell.
Some species like citrus, when cells or nucellus starts division and it results in embryo. This happen in megaspore mother cell where meiosis division does not take place. Thus diploid embryo sac is produced by mitosis.
Thus in some apomicitc species embryo appears normal but produces diploid cells.
Can an unfertilised, apomictic embryo sac give rise to a diploid embryo ? If yes, then how ?
Apomictic embryos in Citrus arise from
Despite high level of heterozygosity, the progeny derived from seed of a cross pollinated plant was found to be completely uniform. One reason for this may the phenomenon of
Are pollination and fertilisation necessary in apomixis? Give reasons.
Production of seed without fertilization is called