Question

The meiospores of yeast are nonmotile and called-
(A)Aeciospores
(B)Aplanospores
(C)Ascospores
(D)Basidiospores

Answer 1

Hint: The meiospores of yeast are nonmotile and are contained in an ascus or that was produced inside an ascus. This type of spore is particular to fungi classified as ascomycetes. Ascomycetes are spore shooters.

Complete answer:
The meiospores of yeast are nonmotile and called Ascospores. Ascospores are formed in ascus under optimal conditions. Typically, one ascus will contain eight ascospores (or octad). An ascus is defined as the sexual spore-bearing cell produced in ascomycete fungi.

Additional Information: Ascomycota - It is a phylum of the Fungi that, along with the Basidiomycota, forms the very known subkingdom Dikarya. Its members are commonly referred to as the sac fungi or ascomycetes. It's the biggest phylum of Fungi, with over 64,000 species. The eight spores are produced by the meiosis which is then followed by a mitotic division. Two meiotic divisions turn the first diploid zygote nucleus into four haploid ones. That is, the only original diploid cell from which the entire process begins contains two complete sets of chromosomes. In preparation for meiosis, all the DNA of both sets is duplicated, to form a complete of 4 sets. The nucleus that contains the four sets divides two times, due to which separating into four new nuclei – each of which has one complete set of chromosomes. Following this process, the four new nuclei duplicate its DNA and undergoes a division by the process known as mitosis. As a result, the ascus will contain 4 pairs of spores in it. Then the ascospores are released from the ascus.
So, the correct answer is ‘Ascospores’.

Note: Many of us get confused between Aeciospores and Ascospores. The Aeciospores are one of several different types of spores formed by Rusts. They each have 2 nuclei and are typically seen in the chain-like formations in the aecium.