Pair of chromosomes in maize

After culturing the anther of a plant, a few diploid plants were found along with haploid plants. The diploid plants could have arisen from

Calcium deficiency results in the formation of an egg with

Development of an egg without fertilization is called

Genetically identical progeny is produced when an individual

Which of the following option is not correct about sexual reproduction

$(I)$ Gametes fuse to form the zygote

$(II)$ It is an elaborate, complex and fast process as compared to asexual reproduction

$(III)$ Offspring sare not identical to the parents