C-Fern Report

A) To completely explain the morphology of the adult sporophyte individual of Ceratopteris richardii is quite easy given that I examined it in lab. In nature, when looking at an adult sporophyte of a C-fern, you will take notice to its array of large, divided, green leaves and stems. In lab, though, the morphology of the C-fern in its adult stage appeared to be small with a short stem and a single leaf. What is known is that a C-fern has 2 different systems that fully explain its structures. The leaves and stems make up what is called the shoot system. Leaves are made up of an upper and lower epidermis, as well as mesophyll. What's interesting about this vascular plant is that instead of producing seeds, it produces spores. The production of spores on the adult sporophyte occurs inside a specialized structure called a sporangium that is located on the margins of fertile leaves. Stems, which are connected to the leaves, can also be called a rhizome, which is a horizontal underground structure that produces the root and shoot systems. The stem is connected to a root that is part of the root system. This system is what the shoot system solely relies on for structural support.

2) A warm temperature of 22 degrees Celsius would be an ideal climate for the C-fern spores to germinate. To keep the spores moist they were contained in a Petri plate under special grow lights.

B) The purpose of this paper was to get a complete understanding of Alternation of Generations. The C-fern that was up for study is very a unique plant that has certain fundamental properties. These fundamental properties help when learning and understanding the life cycle of different plants. By understanding this concept to its fullness one will eventually know the essentials that lie beneath plant biology as well as how each group of plants share a difference in their life cycles.

C) This project consisted of 6 main tasks that were followed to culture the c-fern. The first procedure was to obtain a sterile Petri plate that contained a nutrient agar known as Hatcher's medium (lab). To culture a spore, 0.5 ml of spore suspension was drawn up from a sterile pipette and released into the Petri plate. Once the Petri plant was securely closed it was placed in the grow room located inside the lab room where the temperature remained 22 degrees Celsius and the light intensity about 1110 lux. As weeks went on, our duty was to examine differences in the spore's appearance. A dissecting microscope was used to make clear observations of the C-fern's development. While using the dissecting microscope, I first examined if the spores I cultured germinated, if so, I collected all observable data at a magnification at 27x. Once the spores germinated I observed its different forms; I found 2 distinct forms of the spore at a magnification of 40x. Once the spores completely germinated, they developed into visible female and male gametangia with different morphologies. The next big procedure was to prepare a wet mount using a slide and a cover slip with an adequate amount of water and observe both the male and female gametangia. Using a compound microscope and 40x magnification, what was visible was sperm leaving the gametangium and swimming toward the female, the sperm moved in a swirling motion. Throughout the lab the Petri plates remained in the grow room for the majority of the time with lights scattered around

D) Results & Discussion

1) The Spore

The color of the ungerminated C-fern spore wall appeared to be brown in color with tints on yellow.

b) The spore is a reproductive structure that functions in creating a new plant species. Spores are made up of an ornamented spore wall that aids in dispersal and resists in decay (PowerPoint). They are usually referred to as being homosporous because the visible spores were shown to be identical. By imbibing a sufficient amount of water into the spore and creating physiological and metabolic activity results in a process called germination (PowerPoint). Environmental factors such as water, the temperature and the amount of light aids in the process of germination (National 1995). If the temperature is too hot or too cold, germination might not occur. With the correct amount of light and at a certain temperature the spores will germinate and kick-start the life cycle. The spore wall is ornamented in a way that it contains sporopollenin that functions as a resistant to decay and physical damage; it also aids in dispersal (PowerPoint). This pattern relates to germination because during germination the spore must be protected and be resistant to certain environmental changes or the cycle will not persist.

2) Gametophyte nutrition, growth and physiology

Macro-Nutrient: Function:

Carbon Structure

Hydrogen Structure

Oxygen Structure

Nitrogen Plant growth

Phosphorus Energy

Sulfur Coenzyme

Potassium Movement

Calcium Pollen development

Magnesium Chlorophyll structure

Micro-Nutrient: Function:

Iron Chlorophyll synthesis

Manganese Aids in photosynthesis

Zinc Enzyme activation

Copper Electron transport

Boron Meristematic activity

Molybdenum Nitrogen Metabolism

Chlorine Turgor balance of cells

(PowerPoint 12: Growth/Nutrition)

b) Gametophytes obtain the most essential elements from water. Structures as well can help the gametophyte obtain nutrients from the agar. Rhizoids are strand-like projections present on the gametophyte that also aid in obtaining nutrients (Raven 2005).

c) Gametophytes in vascular plants are not capable of photosynthesis being that its not the dominant plant, as is the sporophyte generation. The sporophyte contains leaves that have photosynthetic pigments whereas the gametophyte does not. Gametophytes tend to be short lived and disappear once the adult sporophyte sprouts, therefore photosynthesis could not take place (PowerPoint).

d) The gametophyte needs a sufficient amount of light for it