Q.2 - Biology

Question

Which of the following statements is true? 

a. A basidium is the fruiting body of a mushroom producing fungus, and it forms four basidiocarps. 

b. The result of the plasmogamy step is four basidiospores. 

c. Karyogamy results directly in the formation of mycelia. 

d. A basidiocarp is the fruiting body of a mushroom producing fungus. 

Step-by-Step Solution

Answer

The correct answer is (d) A basidiocarp is the fruiting body of a mushroom producing fungus. 

Step1. Introduction

The fungi in the Phylum Basidiomycota are easily recognizable under a light microscope by their club-shaped fruiting bodies called basidia (singular, basidium). 

Step2. Explanation of the correct answer

d. A basidiocarp is the fruiting body of a mushroom producing fungus. 

The fruiting bodies of a basidiomycete form a ring in a meadow, commonly called “fairy ring”  The body of this fungus, its mycelium, is underground and grows outward in a circle. As it grows, the mycelium depletes the soil of nitrogen, causing the mycelia to grow away from the center and leading to the “fairy ring” of fruiting bodies where there is adequate soil nitrogen 

Step3. Explanation for Incorrect Options

a. A basidium is the fruiting body of a mushroom producing fungus, and it forms four basidiocarps. 

Post-meiotic mitosis occurs inside the basidium and each nucleus migrates to a single spore, resulting in the production of eight basidiospores.

b. The result of the plasmogamy step is four basidiospores. 

Plasmogamy results in the formation of dikaryon, i.e. two nuclei per cell. 

c. Karyogamy results directly in the formation of mycelia. 

Karyogamy results in the fusion of haploid nuclei and the formation of a diploid nucleus. Once karyogamy occurs a diploid cell is formed that undergoes meiosis immediately, which is then followed by post-meiotic mitosis generating with eight haploid ascospores.