1. Life cycle showing zygotic meiosis
- When Protist is haploid and meiosis occurs in zygote then it is known as zygotic meiosis.
- In this type of life cycle during sexual reproduction gametes are formed by mitosis.
- These gametes are haploid. These gametes fuse to form a diploid zygote.
After that meiosis takes place in zygote, as a result haploid cells are formed again.
Note : In this type of life cycle the zygotic phase is only diploid and remaining all the phases are haploid so this type of life cycle is known as haplontic life cycle.
2. Life cycle showing gametic meiosis
- When Protist is diploid and meiosis takes place during gamete formation, then it is called gametic meiosis.
- In this type of life cycle during sexual reproduction, meiosis takes place in diploid cell , due to which haploid gametes are formed.
Now haploid gametes fuse to form diploid zygote. And after that mitosis takes place in zygote , due to which diploid cells are formed again.
Note : In this type of life cycle only gametic phase is haploid and remaining all phases are diploid so this type of life cycle is known as diplontic life cycle.