Question

After karyogamy followed by meiosis, spores are produced exogenously in

• A. Neurospora
• B. Agaricus
• C. Alternaria
• D. Saccharomyces

Answer 1

The Correct Option is B

The question aims to identify which organism produces spores exogenously after karyogamy followed by meiosis. Let's explore the options step-by-step:

1. Karyogamy and Meiosis: These are two crucial processes in sexual reproduction of fungi.
   • Karyogamy refers to the fusion of two haploid nuclei to form a diploid nucleus.
   • Meiosis is the process that follows, leading to the formation of haploid spores.
2. Neurospora:
   • Neurospora belongs to the phylum Ascomycota. In this group, after karyogamy and meiosis, spores (ascospores) are produced endogenously in a structure called an ascus.
3. Agaricus:
   • Agaricus, a genus of mushrooms, belongs to the Basidiomycota. In these fungi, after karyogamy and meiosis, spores (basidiospores) are produced exogenously on structures called basidia.
4. Alternaria:
   • Alternaria is part of the Deuteromycetes or Fungi Imperfecti, which often do not have a distinct sexual reproductive cycle involving karyogamy and meiosis.
5. Saccharomyces:
   • Saccharomyces, often used in baking and brewing, is classified under the Ascomycota. In this group, spores are also produced endogenously inside an ascus.

From the explanation above, Agaricus is the correct answer as it is the only organism in the given options that produces spores exogenously (on the outside of basidia) after karyogamy and subsequent meiosis.