Question

The Torula stage of Mucor is rich in which of the following mediums?
A. Sugar
B. Pesticide
C. Antibiotic
D. All of the above.

Answer 1

Mucor is a group of species belonging to the microbial genus. It consists of about forty different types of species. They are commonly found in the soil, in the digestive system of living organisms, plant surfaces and rotten vegetable matter.

**Complete answer :**
Mucor are also known as moulds. The colonies of Mucor are typically white to beige in colour. Sometimes, the colony can also be grey in colour. The colonies are fast growing. The older colonies become brownish in colour from grey as the result of development of spores.
The Mucor species are differentiated from other species by the distinctive shape and insertion of columella and the lack of stolons and rhizoids. The spores or sporangiospores in Mucor can be simple or branched. It forms apical, globular sporangia that are supported and elevated by the columella, which is column-shaped. Some of the species of Mucor produce chlamydospores.
In Mucor, the mycelium or the hyphae can disintegrate and break down into very short filaments. This condition arises when the organism is allowed to grow in a glucose or sugar rich liquid media. When the Mucor is grown in the liquid media, the mycelium breaks down into smaller fragments. These fragments further attain a small, independent and globular structure and are actually single celled. This particular condition in which a Mucor behaves in a sugar contained media is referred to as the torula stage of Mucor. Initially, it was assumed that the small spherical cells known as oidia may be a different species altogether. However, later it was discovered as an unusual behaviour of Mucor in relation to the sugar medium.
Hence, the correct option here is option A.

Additional information
The genus Mucor is commonly called mold. They are mostly saprophytic in nature. The vegetative plant body is eucarpic and it consists of white cottony mycelium which bears heavy branching of mycelium. The mycelium spreads all the substratum. The hyphae or mycelium are usually prostrate and some of the mycelium penetrates into the substrate.

Note: In Mucor, when it is allowed to grow on sugar rich media, it produces small, spherical cells which are known as oidia. The oidia are thin walled like structures. After formation of oidia, it gets detached from the body of Mucor and increases by budding like in yeast. The stage is known as torula stage.