Question

Algae are known to reproduce asexually by a variety of spores under different environmental conditions. What are the spores and different conditions under which they are produced?

Answer 1

Asexual reproduction is a process of formation of various types of sporangia. The spores detach from the parent plants, then it germinates and gives birth to new plants.
Many small algae reproduce asexually by fragmentation or by ordinary cell division. On the other hand, larger algae reproduce asexually by spores.

Complete Answer:
Some green algae produce non-motile spores called Aplanospores. While, others produce zoospores.
The different types of spores that are produces by algae for asexual reproduction are as follows:
Neutral spores – The protoplast of a certain cell in the thallus, directly functioning as a spore is called neutral spore.
Example: Ectocarpus
Stat spores – These are thick-walled pores. These are produced as diatoms.
Hypnospores – Here the protoplasm separates from the cell wall and develops a covering around itself. These are formed in unfavourable conditions.
Example: Ulothrix , Vaucheria etc.
Akinetes - These are also reproductive structures found in plants. These are also formed in unfavourable conditions.
Example: Spirogyra
Zoospores - These are flagellated spores that use a flagellum for locomotion. Zoospores are also called a swarm spore. These spores are created by some protists, fungi and bacteria to propagate themselves asexually.
Example: Chlamydomonas

Note:
Asexual reproduction is a method of reproduction. It does not involve the union of sex cells or gametes. The progeny produced by asexual reproduction either by unicellular or multicellular organisms, inherit the full set of genes of their single parent. Asexual reproduction is a primary reproduction from generally seen in the single cell organisms like Bacteria.