Question

How many ascospores are found in an ascus?
a. 6
b. 8
c. 4
d. 2

Answer 1

Hint: Fungi are kept in a different kingdom but these share some of the morphological, biochemical and genetic features with both animals and plants, while some features are limited to fungi which differentiate them from others. These are generally found in damp areas or on the surface of other plants.

Complete answer:
Members of fungi possess a chitinous cell wall; membrane bound organelles like nucleus, mitochondria, etc. These are heterotrophic in nature and can be multicellular or unicellular. The fungi grow into tubular, elongated filamentous structures called hyphae which contain multiple nuclei. A collection of hyphae is called mycelium. They can reproduce by sexually as well as asexually . These produce spores which have the ability to germinate into new organisms. The spores are formed as a result of sexual and asexual reproduction which develops into fruiting bodies when dispersed in atmosphere during favorable environment.

 In Ascomycetes group of fungi, ascospores are produced as a result of sexual reproduction. These spores are formed in a sac like structure called ascus. Ascospores are produced under normal conditions and a single ascus contains about eight ascospores (also called octad). Basically, these spores are produced as a result of meiosis and mitosis in the zygote. After the zygote is formed two meiotic divisions occur which turns the original diploid zygote into four haploid zygotes. After that one mitotic division occurs in all four cells to divide the duplicated DNA. Then eight haploid cells are produced after the mitotic division. Therefore, a single ascus contains eight ascospores.

Hence, The correct answer is option (B).

Note: In both sexual and asexual reproduction spores are produced by the fungi. These spores disperse from the parent body when the sporangium bursts and releases numerous spores into the atmosphere. These spores land on various surfaces and grow as an individual on surfaces which support life.