Question

If hyphae are continuous tube filled with multinucleated cytoplasm it is known as (a) Septate hyphae (b) Coenocytic hyphae (c) Mycelium (d) None of these

Short answer

The correct answer is (b) Coenocytic hyphae.

Step-by-step solution

Understanding Hyphae

Hyphae are long, branching filamentous structures of fungi. They are the main mode of vegetative growth, and are collectively called a mycelium.

Identifying Septate Hyphae

Septate hyphae are characterized by walls called septa, which divide the cytoplasm of the hyphae into distinct cells, each containing one or more nuclei.

Identifying Coenocytic Hyphae

Coenocytic hyphae, on the other hand, are not partitioned by septa. Instead, they are continuous tubes filled with multinucleated cytoplasm. This means they are one large cell filled with many nuclei, fitting the description in the exercise.

Understanding Mycelium

Mycelium refers to the collective mass of hyphae. It does not refer to a specific type of hyphae, so it doesn't fit the description given in the exercise.

Key concepts

Coenocytic Hyphae

Coenocytic hyphae are a fascinating structure found in certain fungi. Unlike septate hyphae, coenocytic hyphae do not have divisions known as septa. Instead, they form long, continuous tubes that contain many nuclei within the same cytoplasmic space.
This unique structure allows for efficient nutrient distribution and rapid growth, as there are no barriers to slow down the movement within the tube. Because of this, coenocytic hyphae can spread quickly, which can be advantageous for the fungi's growth and colonization of new areas.
When you think of coenocytic hyphae, imagine a sausage casing filled with a nutrient-rich filling that stretches and moves to support the growth of the fungi. This unique characteristic is vital for certain types of fungi, like zygomycetes, enabling them to thrive in various environments.

Septate Hyphae

Septate hyphae are the more commonly observed form of hyphae that are divided into cells by cross-walls called septa. These septa have pores which allow for the flow of cytoplasm and organelles between cells.
This division into distinct cells allows the fungal organism to regulate cell processes more precisely and can help in the damage control of individual cells. If one cell is damaged, the septa can limit the impact to just that cell, preventing it from affecting the entire filament.
Some fungi, like ascomycetes and basidiomycetes, often have septate hyphae. The presence of septa provides structural support to these organisms and allows them to form complex and robust networks that contribute to the overall stability and functioning of the fungi.

• Each segment typically contains one or two nuclei.
• The pores in septa allow communication between cells.
• Critical for growth and survival in structured environments.

Mycelium

Mycelium is the term used to describe the collective mass of hyphae. Mycelia can vary greatly in shape and size, depending on the environment and the type of fungi.
This network of hyphae functions like a root system for fungi, absorbing nutrients from the surrounding environment and serving as a fulcrum for growth and reproduction. Mycelium is essential for the ecological role of fungi, such as breaking down organic matter and forming symbiotic relationships with plants.
Although it might not fit the peculiar description of coenocytic hyphae, mycelium is an indispensable part of how fungi operate. The spread of mycelium is a key factor in the decomposition of organic materials, helping to recycle nutrients within ecosystems.
In nature, mycelium often forms a vast and intricate underground network that is sometimes referred to as the "wood wide web," connecting various plants and organisms. This relationship highlights the fundamental role of mycelium in maintaining healthy soil and ecosystem dynamics.