Chapter 20, Problem 21A

Summary Introduction

Introduction :

Fungi are among the oldest and the largest group of organism on earth. All fungi are either unicellular or multicellular eukaryotic heterotrophs. Fungi have a cell wall composed of chitin. There are about 100,000 identified species of fungi. Most fungi reproduce asexually or sexually through spores. A spore is the reproductive haploid cell that develops into a new organism without the fusion of gametes.

Answer to Problem 21A

Correct answer :

The correct answer is option (B) haploid.

Explanation of Solution

Explanation/justification for the correct answer :

Option (B) haploid. The fruiting body of a spore-forming fungus is called a sporophore. The classification of fungus is based on the type of spore it produces. The sporophore bears a haploid structure called sporangium. The sporangium is the sac or case in which spores are produced. So, the correct answer is option (B).

Explanation for incorrect answer :

Option (A) bud. Unicellular yeast cells reproduce asexually by budding. A bud develops on the body of the parent cell and then pinches off to form a new individual. So, this is an incorrect option.

Option (C) diploid. Most fungi reproduce asexually or sexually through spores. In sexual reproduction, the zygote formed by the fusion of two hyphae is a diploid that produces haploid spores by meiosis. So, this is an incorrect answer.

Option (D) fragmented. Fragmentation occurs when the mycelium of a fungus physically breaks apart or is fragmented. It is an asexual type of reproduction. Hence, this is an incorrect answer.