Q.11 - Biology

Question

Members of which phylum establish a successful symbiotic relationship with the roots of trees? 

a. Ascomycota

b. Deuteromycota 

c. Basidiomycota 

d. Glomeromycota 

Step-by-Step Solution

Answer

The correct answer is (d) Glomeromycota 

Glomeromycota establish a successful symbiotic relationship with the roots of trees.  

Step1. Introduction

The kingdom Fungi contains five major phyla that were established according to their mode of sexual reproduction or using molecular data. 

The five true phyla of fungi are the Chytridiomycota (Chytrids), the Zygomycota (conjugated fungi), the Ascomycota (sac fungi), the Basidiomycota (club fungi) and Glomeromycota. 

Step2. Explanation of the correct answer

The Glomeromycota which comprises about 230 species that all live in close association with the roots of trees. Fossil records indicate that trees and their root symbionts share a long evolutionary history.

The glomeromycetes do not reproduce sexually and do not survive without the presence of plant roots. 

Step3. Explanation for Incorrect Options

a. Ascomycota

The majority of known fungi belong to the Phylum Ascomycota, which is characterized by the formation of an ascus (plural, asci), a sac-like structure that contains haploid ascospores.  

Asexual reproduction is frequent and involves the production of conidiophores that release haploid conidiospores. Sexual reproduction starts with the development of special hyphae from either one of two types of mating strains . 

b. Deuteromycota 

Imperfect fungi—those that do not display a sexual phase—use to be classified in the form phylum Deuteromycota, , a classification group no longer used in the present, ever-developing classification of organisms. While Deuteromycota use to be a classification group, recent molecular analysis has shown that the members classified in this group belong to the Ascomycota or the Basidiomycota classifications 

c. Basidiomycota 

The basidiomycetes group is the group of fungi that gathers the representatives with the highest degree of structural complexity. Although fungi do not form true tissues, most species form macroscopic fruit with specialized hyphae organized in pseudotexes.

The lifecycle of basidiomycetes includes alternation of generations. Spores are generally produced through sexual reproduction, rather than asexual reproduction. The club-shaped basidium carries spores called basidiospores.