Question

Why are ascospores considered sex spores? • What is the name of the elongated or oval sac within which four or eight ascospores typically form? Why does it sometimes contain four and sometimes eight ascospores? What is the fruiting body of an ascomycete called, whose shape is typically similar to a cup or bowl? What type of hyphae are they composed of, septate or cenocytic? Monokaryotic or heterokaryotic?

Answer 1

1. Ascopores are the sexual reproductory part of fungi. They are called sex spores because during the sexual reproduction in fungi, the two gametes combine to form an ascus. Inside the ascus, the zygote will undergo multiple divisions to form atmost eight ascospores that are then released once the asus bursts in humid conditions or any other suitable conditions. These ascospores then develop into mycelium to form the fungi.

2. The elongated or oval sac within which the ascospores develop is known as the ascus.

3. The ascospores are formed due to successive events of mitotic and meiotic cycles. The first meiosis produces two sets of haploid that results in four spores. Further meiosis results in the haploid formation of each of the four nuclei which then gives rise to eight ascospores. The four or eight number can vary if one stage of meiosis is followed by a stage of mitotic cycle.

4. The fruiting body of the ascomyte is called an asci.

5. The hyphae is septate and heterokaryotic in nature.