Final answer:
The ocean is the largest ecosystem, a fish shows bilateral body symmetry, and lactic acid is formed by Lactobacillus delbrueckii.
Step-by-step explanation:
The largest ecosystem is the ocean, which covers 75 percent of Earth's surface and consists of various sub-ecosystems like shallow ocean, deep ocean water, and deep ocean bottom. These marine ecosystems are teeming with life and are crucial to the planet's biodiversity.
A fish exhibits bilateral symmetry, meaning their body can be divided into two identical halves on either side of a central plane. This type of symmetry is common among many animals and is associated with a more streamlined and directional mode of life.
The amino acid that is formed by the microbial process of Lactobacillus delbrueckii is lactic acid. This is a product of lactic acid fermentation and is an important compound in various biological and industrial processes.