Haplontic

Definition

Haplontic refers to a life cycle in which the main form is haploid, with a brief diploid stage occurring only during the zygote phase. This life cycle is typical of many algae and fungi.

5 Must Know Facts For Your Next Test

1. In haplontic life cycles, the organism spends most of its life in the haploid state.
2. Fertilization occurs to produce a diploid zygote, which undergoes meiosis to return to the haploid state.
3. Haplontic life cycles contrast with diplontic and haplodiplontic (alternation of generations) cycles.
4. Common examples of organisms with haplontic life cycles include certain green algae like Chlamydomonas.
5. This type of life cycle is important for understanding early plant evolution and reproduction.

Review Questions

• What is the primary characteristic of a haplontic life cycle?
• How does fertilization affect the ploidy level in a haplontic organism?
• Can you name an example of an organism that follows a haplontic lifecycle?

Related terms

Diplontic: A life cycle in which the main form is diploid, with gametes being the only haploid stage.

Haplodiplontic: A life cycle involving both multicellular diploid and multicellular haploid stages, also known as alternation of generations.

Zygote: A diploid cell resulting from the fusion of two haploid gametes; it undergoes meiosis in haplontic organisms.