Gametes are normally always haploid (N) structure. In haploid organisms, they are never formed by meiosis. They are formed by mitotic divisionss, In haploid organism, there is zygotic meiosis i.e., it takes place in the zygote formed as a result of gametic fusion. Meiosis occurs in the zygote to form haploid spores which give rise to haploid organisms.

Although reproduction is not a vital process for the survival of an organism but however it is essential for the survival of a population of a species and moreover it adds new individuals in a population.

(i) Rotifers/honeybees/some lizards/turkey.
(ii) Parthenogenesis.

The healthy, virus-free potato plants can be obtained from virus infected desired potato variety by meristem culture (Tissue culture technique) because meristems are not affected by viruses, they remain virus free even in the plants affected by virus. Explants from the meristematic regions like apical or axillary buds or from the nodal segments are taken and cultured on the solid medium enriched by cytokinin and auxin in suitable ratio under aseptic condition. Adventitious roots and shoots develop from the explant resulting in the formation of new plantlets which are finally transferred to the field.

Earthworm, Sponge, Tapeworm, Leech.

Gardener did a mistake by selecting a monocotyledonous stock for grafting a dicotyledonous scion. Usually grafting is between two dicotyledonous plants where cambium develops at the place of grafting.

1. Sweet potato
2. Chara
3. Marchantia
4. Tapeworm
5. Rabbit.

Role of tapetum in the pollen grain wall formation
During microsporogenesis, the cells of tapetum provide various enzymes, hormones, amino acids and other nutritive materials to the dividing microsporocytes. The main functions of tapetum are:
1. Transportation of nutrients into anther locule at the time of meiosis in spore mother cells.
2. Secretion of enzymes and hormones.
3. Production of Ubisch bodies which are coated with sporopollenin to cause thickening of exine.
4. Secretion of any oily material (pollen kit) over outerside of mature pollen.
5. Secretion of special proteins for pollen to recognise compatibility.

Sporulation is the process in which the products of multiple fission become individually surrounded by a cyst wall before being released from the parent; each of them is a spore.  The sporulation remain dormant during unfavourable conditions and germinate when conditions become favorable. 

Yeast reproduces asexually by budding under favourable conditions.

Vegetative reproduction involves a single parent and there is no formation and there is no formation and fusion of gametes; hence it is considered as asexual reproduction.

Meiosis is an essential event in the sexual cycle of any organism because:
(i) It maintains the number of chromosomes fixed (2n) from generation to generation. Haploid gametes are formed as a result of meiosis. Diploid (2n) condition is restored during fertilization.
(ii) It increases the genetic diversity and variation due to crossing over between homologous chromosomes and their random segregation.