Reproduction and Fungi Structures

In this lesson, students explore the phenomena of reproduction with a mushroom dissection, connecting the different structures of the fungi with its ability to reproduce. 

• Like some species of fish, most species of fungi can also reproduce both asexually and sexually. 
• The ability to reproduce both sexually and asexually offers fungi an evolutionary advantage.
• Asexual reproduction is more efficient, taking less time and producing more offspring. In asexual reproduction, the spores hold a copy of the parent’s full set of genetic information.
• When the environment changes, it is harder for asexually reproducing organisms to adapt because there is very little genetic variation.
• Fungi have different structures that help them reproduce and pass along their genetic information to offspring.
  
  

• Why is it beneficial for fungi to be able to reproduce asexually?
• Why is asexual reproduction sometimes not beneficial for fungi (or any species)?
• What conditions might cause a species of fungi to reproduce sexually?
• Why are mushrooms important structures?
• How do spores turn into new organisms?
  
  

Misconception: In natural selection, organisms “try” to adapt so they can get what they need.

Fact: The genetic variations that lead to natural selection occur randomly. Natural selection also depends on the environment because the organisms with genes best suited to their environment will survive and reproduce.

Misconception: Mushrooms and other fungi are a type of plant.

Fact: Fungi are a kingdom of their own, in addition to the animal and plant kingdoms.

Allele : a form of the same gene that has small differences in the sequence of DNA bases

Asexual Reproduction :  reproduction that requires only one parent (e.g., binary fission, budding, and fragmentation)

Chromosome : a threadlike structure of DNA and protein; found in the nucleus of eukaryotic cells; a discrete package of genetic material

Reproduction :  the ability of a mature organism to have offspring

Sexual Reproduction : the creation of a new individual from combined genetic information of two parents of different sexes

Reproduction of Fungi

Many species of fungi can reproduce both asexually and sexually depending on the conditions of the environment. There are about 1.5 million species of fungi in the world. This includes baking yeast, the microscopic organisms known for causing athlete’s foot, and a 605-ton honey mushroom in Oregon.

We’ll focus here on those species of fungi that produce mushrooms. The mushrooms that most people are familiar with are fruiting bodies. This means that they produce spores. A spore is a seed-like cell that is released by mature mushrooms. It contains all of the material needed to grow into a new fungus.

First, the spores begin to grow hyphae. Hyphae are the threadlike structures that can fuse together into a network of tissues called mycelium. Once the network of mycelium grows large enough, it forms mushrooms. A mature mushroom can produce millions or billions of spores in a single day.

This process can be very complex depending on the species of fungi. Fungi don’t have male or female organisms. However, they are able to combine genetic information. This allows them to introduce genetic variation into the population.

For the hands-on activity of this lesson, students figure out the external structures of mushrooms they cultivate in the classroom to examine how some fungi grow and reproduce. Students experiment with dissecting a mushroom, to gather investigative phenomena about its spores, and its cells under a microscope. Students use their observations and diagrams as data to help them analyze the relationship between the mushroom’s structures and its ability to reproduce.