An example of endomycorrhiza isa)Rhizobiumb)Agaricusc)Nostocd)GlomusCorrect answer is option 'D'. Can you explain this answer?

Question

Answer

NCERT 12th page no. 188

Answer

Glomus is a genus of arbuscular mycorrhizal fungi, and all species form symbiotic relationships with plant roots. Glomus is the largest genus of  fungi, with 85 species described,

Answer

Endomycorrhizal fungi (more commonly referred to as endomycorrhizae) is one of the major types of known mycorrhizae which differs from the another type of mycorrhizae, ectomycorrhizae, in structure. Unlike ectomycorrhizae which form a system of hyphae that grow around the cells of the root, the hyphae of the endomycorrhizae not only grow inside the root of the plant but penetrate the root cell walls and become enclosed in the cell membrane as well. This makes for a more invasive symbiotic relationship between the fungi and the plant. The penetrating hyphae create a greater contact surface area between the hyphae of the fungi and the plant.
Glomus is a genus of endomycorrhizal fungi, and all species form symbiotic relationships (mycorrhizas) with plant roots.

Answer

Nostoc

Answer

Endomycorrhiza, also known as arbuscular mycorrhiza, refers to a type of mutualistic symbiotic association between certain fungi and the roots of most vascular plants. The correct answer for the example of endomycorrhiza is option 'D', Glomus.

- What is Endomycorrhiza?
Endomycorrhiza is a mutualistic association formed between a group of fungi known as Glomeromycota and the roots of plants. It is the most common form of mycorrhiza, found in about 80% of plant families, including many important agricultural crops.

- Glomus and Endomycorrhiza:
Glomus is a genus of fungi that plays a significant role in forming endomycorrhizal associations. It forms mutualistic symbiosis with the roots of plants, where both the fungus and the plant benefit from the association.

- Mutualistic Relationship:
Endomycorrhiza is a mutualistic relationship, meaning both the fungus and the plant benefit from the association. The fungus colonizes the root cells of the plant, forming specialized structures called arbuscules and vesicles. These structures facilitate nutrient exchange between the fungus and the plant.

- Benefits for the Plant:
1. Increased nutrient uptake: The fungus extends its hyphae into the soil, greatly increasing the surface area available for nutrient absorption. This enhances the plant's ability to acquire essential nutrients, such as phosphorus, nitrogen, and micronutrients.
2. Enhanced water uptake: The extensive network of fungal hyphae helps the plant in absorbing water more efficiently, especially in drought conditions.
3. Disease resistance: Endomycorrhizal associations have been shown to enhance the plant's resistance to certain pathogens and diseases.
4. Improved tolerance to environmental stresses: Plants associated with endomycorrhiza exhibit better tolerance to various environmental stresses, including heavy metal toxicity, salinity, and extreme temperatures.

- Benefits for the Fungus:
1. Organic carbon supply: The plant provides the fungus with carbohydrates produced through photosynthesis. These carbohydrates serve as an energy source for the fungus.
2. Sheltered environment: The plant root provides a protected and nutrient-rich environment for the fungus to grow and reproduce.

- Conclusion:
Endomycorrhiza, exemplified by Glomus, is a mutualistic association between certain fungi and the roots of plants. This symbiotic relationship benefits both the fungus and the plant by enhancing nutrient uptake, water absorption, disease resistance, and tolerance to environmental stresses.

Top Courses for NEETView all

Daily Test for NEET Preparation

NEET Mock Test Series - Updated 2026 Pattern

Topic-wise MCQ Tests for NEET

Biology Class 11

DPP: Daily Practice Problems for NEET

Top Courses for NEET

Top Courses for NEET

Related Content

Mock Test & Practice

Main Subjects

Guided Learning

Revision

Competitive & Government Exams