Question

Given below are two statements:
Statement (I): Yeasts are unicellular fungi that do not show sexual reproduction
Statement (II): Budding is asexual mode of reproduction observed in haploid and diploid yeast cells
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are true.
• B. Both Statement (I) and Statement (II) are false.
• C. Statement (I) is true but Statement (II) is false.
• D. Statement (I) is false but Statement (II) is true.

Hint:

While yeasts are unicellular, they undergo a complete sexual cycle involving meiosis and mating, producing sexual ascospores.
This makes Statement (I) false.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Yeasts are eukaryotic, unicellular fungi that belong primarily to the phylum Ascomycota.
They can reproduce through both asexual and sexual pathways depending on environmental conditions and nutrient availability.

Step 2: Detailed Explanation:
Let us evaluate both statements describing yeast reproduction:
Statement (I) claims that yeasts do not show sexual reproduction.
Many yeast species, such as the model organism Saccharomyces cerevisiae, undergo sexual reproduction.
Under nutrient-poor conditions, diploid yeast cells undergo meiosis to produce four haploid sexual ascospores inside a protective ascus.
These haploid spores can subsequently germinate and mate to restore the diploid phase.
Therefore, Statement (I) is false.
Statement (II) describes asexual budding in yeast.
Budding is the primary asexual mode of vegetative reproduction in yeast.
During this process, a small protuberance (bud) emerges from the mother cell, receives a copy of the replicated nucleus, and pinches off to form a new individual.
This process occurs in both haploid cells and diploid cells during their respective vegetative growth phases.
Therefore, Statement (II) is true.

Step 3: Final Answer:
Thus, Statement (I) is false but Statement (II) is true, which corresponds to option (D).