where does syngamy occurs in majority of algae

 Syngamy occurs outside the body of the algae in majority cases. Syngamy occurs generally in water(ie. external medium),this type of fertilisation is called external fertilisation.

Process of sexual reproduction which involves meiosis and syngamy is?

Amphimixis ? syngamy? Apomixis? Asexual , aposporous? meiosis? Agamospermy? diplospory? archesporium ? megagematophyte?

The process of fusion between haploid male nucleus and egg nucleus is known as amphimixis. It is also known as syngamy. The process is known as fertilization which leads to formation of a diploid zygote. It leads to the recombination of character which causes variation. It is a mode of sexual reproduction. The haploid gametes are formed by meiosis.

Apomixis is a mode of asexual reproduction. The development of plants takes place without fusion of gametes. The embryo develops without the fertilization of seeds. It is a powerful tool which fixes heterosis. The developed seeds are clones of plant. The ovule undergoes meiosis and forms aposporous initial cells which forms meiosis. It involves only meiosis not syngamy. 

Agamospermy is asexual reproduction in which seeds are produced from unfertilized ovules. The removal of the anthers of a flower in order to prevent self-pollination is known as emasculation. 

In diplospory, the megagametophyte arises from a cell of the archesporium.

Oogamy ? Anisogamy?  spermatids? 

• Oogamy is a system of sexual reproduction in which one gamete (called the egg) is large and nonmotile, while the other (called the sperm) is small and motile. Oogamy is a type of Anisogamy.
  
• During Spermatogenesis, the protoplast of spermatogonium is equally divided into 4 spermatids while during oogenesis, ovum retains the bulk of protoplast and is minimally shared by Polar bodies