Question
Question: What are the successive structures formed in the course of sexual reproduction in _Rhizopus_? A. Z...
What are the successive structures formed in the course of sexual reproduction in Rhizopus?
A. Zygospore, progametangium, gametangium, zygophore.
B. Progametangium, zygophore, gametangium, zygospore.
C. Progametangium, gametangium, zygospore, zygophore.
D. Zygophore, progametangium, gametangium, zygospore.
Solution
Rhizopus is a genus of saprophytic fungi that live on plants and specialized parasitic fungi that live on animals. They can be found in "mature fruits and vegetables," jellies, syrups, leather, bread, peanuts, and tobacco, among other organic substances.
Complete answer:
Rhizopus is a multicellular organism. Human zygomycosis (fungal infection) is caused by some Rhizopus species, which can be fatal. Rhizopus infections are a possible side effect of diabetic ketoacidosis. There are at least eight species in this large genus.
Rhizopus species are filamentous, branching hyphae that lack cross-walls in most cases (i.e., they are coenocytic). They reproduce by spores, both asexual and sexual. Asexual reproduction produces sporangiospores inside a spherical structure called a sporangium. A large apophysate columella atop a long stalk, the sporangiophore, supports sporangia.
Sporangiophores grow among rhizoids that look like roots. When two compatible mycelia fuse in sexual reproduction, a dark zygospore is produced. When a zygospore germinates, it produces colonies that are genetically distinct from either parent.
The somatic hyphae produce zygophores, which are special branches. Progametangium is carried by each zygophore, and gametangium is the terminal portion of progametangium. The protoplasts of two oppositely strained gametangia fuse to form a diploid mass known as a zygospore.
Thus, the correct answer is Option D: Zygophore, progametangium, gametangium, zygospore.
Note:
Many Rhizopus species are used in the commercial production of chemicals and alcoholic beverages.
Cortisone and lactic acid are both produced by R. oryzae.
R. oryzae is also used for heavy metal biosorption in wastewater, while R. stolonifer produces lactic acid, fumaric acid, and cortisone.
Biotin and fumaric acid are made from R. delemar.
Tempeh is a traditional Indonesian food.