Sexual Reproduction of Rhizopus (12 steps)

Question 1

List all 12 steps of sexual reproductions of rhizopus

Answer 1

1. Hyphae from opposite strains grow close together.
2. Swellings form opposite each other.
3. The swellings touch.
4. Nuclei (or gametes) move into each swelling forming progametangia.
5. Cross walls form to produce gametangia, which are held in place by suspensors.
6. The walls between the gametangia dissolve.
7. Many fertilisations produce a number of diploid zygote nuclei.
8. A tough-walled, black zygospore forms around these nuclei.
9. The zygospore (which is diploid) can remain dormant for a long time.
10. When conditions are suitable the zygospore germinates by meiosis.
11. A haploid hypha grows out of the zygospore and produces a sporangium at the tip.
12. The sporangium releases many haploid spores, which blow away to produce new hyphae and mycelia.

Question 2

What are the first 3 steps of sexual reproduction?

Answer 2

1. Hyphae from opposite strains grow close together.
2. Swellings form opposite each other.
3. The swellings touch.

Question 3

What are the second 3 steps of sexual reproduction after the swellings touch?

Answer 3

4. Nuclei (or gametes) move into each swelling forming progametangia.
5. Cross walls form to produce gametangia, which are held in place by suspensors.
6. The walls between the gametangia dissolve.

Question 4

What are the third 3 steps after the walls between the gametangia dissolve?

Answer 4

7. Many fertilisations produce a number of diploid zygote nuclei.
8. A tough-walled, black zygospore forms around these nuclei.
9. The zygospore (which is diploid) can remain dormant for a long time.

Question 5

What are the fourth and final 3 steps after the zygospore (which is diploid) can remain dormant for a long time?

Answer 5

10. When conditions are suitable the zygospore germinates by meiosis.
11. A haploid hypha grows out of the zygospore and produces a sporangium at the tip.
12. The sporangium releases many haploid spores, which blow away to produce new hyphae and mycelia.

Question 6

What does Rhizopus exist as?

Answer 6

It exists as two separate strains called plus and minus strains

Question 7

What is important to know about the plus and minus strains of rhizopus?

Answer 7

Both strains look identical but sexual reproduction can only occur between a plus and a minus strain

Question 8

what should be labelled on a diagram for sexual reproduction?

Answer 8

hypha, cross walls, hyphae from different mycelia, nucleus (gamete), swellings, progametangia, gametangia, nucleus move in, suspensor, wall dissolves, zygospore

Question 9

what should be labelled on a diagram for the structure of Rhizopus?

Answer 9

spore, spores blown away, columella, sporangiophore, mycelium, rhizoids, substrate, hypha, stolon, apophysis, sporangium