Category: Biology Second Paper Lecture Sheet

(i) Lycopodium, Equisetum etc. are medicinal ferns. Homeopathic medicine is made from it.
(ii) Unani herbal medicines are prepared from ferns. These drugs are used in the treatment of ulcers, rheumatic fever, intestinal lesions etc.
(iii) Young stems of ferns are used as anthelmintics.
(iv) Marsilean obtained from Marsilea is used to treat neuralgia.
(v) Medicines for liver diseases are prepared from Selaginella botryoides.
(vi) Herba equisini medicine obtained from Equisetum arvense helps to treat blood purification and urinary tract diseases.
(vii) Medicine for gonorrhea is prepared from Equisetum debile.

1. Human food: Young leaves of Pteris are used as vegetable. The starchy stems and rhizomes of the fern are used as food. Kale and collard greens are favorite vegetables.
2. Animal Feed: Several species of Pteris are used as livestock feed. However, eating harmful and poisonous Pteris causes death of livestock. This is why Pteris is sometimes called a noxious and poisonous weed.
3. Fuel: Coal, oil and natural gas are obtained from the fossils of tree ferns which are used as fuel.
4. The medicine is ready
(i) Lycopodium, Equisetum etc. are medicinal ferns. Homeopathic medicine is made from it.
(ii) Unani herbal medicines are prepared from ferns. These drugs are used in the treatment of ulcers, rheumatic fever, intestinal lesions etc.
(iii) Young stems of ferns are used as anthelmintics.
(iv) Marsilean obtained from Marsilea is used to treat neuralgia.
(v) Medicines for liver diseases are prepared from Selaginella botryoides.
(vi) Herba equisini medicine obtained from Equisetum arvense helps to treat blood purification and urinary tract diseases.
(vii) Medicine for gonorrhea is prepared from Equisetum debile.
5. Beautification: Fern plants are used in various events, home decoration, garden beautification etc. Lycopodium obscurum, also known as Christmas green, is used as a beautifier in Christmas celebrations. Lycopodium, Selaginella etc. are used for decoration.
6. Production of chemicals: Ferns can be used to produce essential chemicals. Potash is obtained from Dryopteris and silicon from Equisetum. Potash is used to make soap and glass.
7. As Fertilizers: Some species of Terris are used as fertilizers on land.
8. Furniture Polish: Equisetum is used in wooden furniture polish.
9. Fireworks: Molecules of Lycopodium burn and emit colorful light. Hence it is called flint plant. Flint plant is used to make fireworks.
10. Antibiotics: Pteri absorb large amounts of arsenic from the soil. So it can be used to treat depression caused by arsenic.

The successive appearance of gametophyte and sporophyte stages in the life cycle of a plant is called generation. Pteris has two stages in its life cycle. Gametophyte state and sporophyte state.
1. Gametophyte stage: The stage of plant life cycle in which gametes i.e. sperm and egg are formed is called gametophyte stage. Spores are produced in sporophyte plants. Spore is the first cell of gametophyte. Spores germinate in favorable environment. The germinated spore divides by mitosis to form a green, flat and cordate prothallus. Fern prothallus is a gametophyte plant. Under its anterior groove the pitcher or flux-shaped female genital archegonia and below the thallus the round or ovoid male genital antheridia grow. Eggs are produced in the archegonium and spermatozoa in the antheridium. Sperm and egg unite to form zygote. The gametophyte phase ends with the formation of the zygote.
2. Sporophyte stage: The stage of plant life cycle in which spores are produced is called sporophyte stage. Gametophytes produce sperm and ovules in plants. A zygote is formed by the union of sperm and egg. Zygote is the first cell of sporophyte. The zygote becomes enveloped by the wall and becomes a zygospore. Zygospore germinates in favorable environment. The germinating zygospore divides repeatedly by the process of mitosis to form the sporophyte plant. The sorus grows on the leaf margin of the sporophyte. The sorus contains sporangia. Inside the sporangium is the spore mother cell. Each spore mother cell divides by meiosis to produce four spores. The sporophyte stage ends with the formation of spores.

The stage of plant life cycle in which gametes i.e. sperm and egg are produced is called gametophytic stage. In sporophyte plants, spores are produced inside the sporangium. The spore is the first cell of the gametophyte stage. Spores germinate in favorable environment to form 4-6 celled protonema. Cells on either side of the protonema divide repeatedly in the process of mitosis to form a green heart-shaped prothallus. Pteris is a companion plant. Flax-shaped archegonia below the anterior groove and spherical or ovoid antheridia below the thallus. Each archegonium produces one ovule and 20-50 spermatozoa in the antheridium. Sperm and egg unite to form a zygote. The gametophyte stage ends with the formation of the zygote.

The stage of plant life cycle in which spores are produced is called sporophytic stage. Gametophytes produce sperm and ovules in plants. A zygote is formed by the union of sperm and egg. Zygote is the first cell of the sporophyte stage. The zygote is enveloped by the wall and becomes a zygospore. Zygospore germinates in favorable environment. The germinating zygospore divides repeatedly in the process of mitosis to form the sporophyte plant. Sporangia are produced along the margins of sporophyte plant leaves. Each sporangium contains 16 spore mother cells. Each spore mother cell divides by meiosis to produce four spores. This condition is called tetrad. As a result, 64 spores are produced in each sporangium. When the spore develops, the wall of the sporangium ruptures and comes out. The sporophyte stage ends with the formation of spores.

The successive appearance of the gametophyte stage and the sporophyte stage in the life cycle of a plant is called generation. There are two phases in the life cycle of Terris. Sporophyte Dasha and Gametophyte Dasha.
1. Sporophyte stage: The stage of plant life cycle in which spores are produced is called sporophytic stage. Gametophytes produce sperm and ovules in plants. A zygote is formed by the union of sperm and egg. Zygote is the first cell of the sporophyte stage. The zygote is enveloped by the wall and becomes a zygospore. Zygospore germinates in favorable environment. The germinating zygospore divides repeatedly in the process of mitosis to form the sporophyte plant. Sporangia are produced along the margins of sporophyte plant leaves. Each sporangium contains 16 spore mother cells. Each spore mother cell divides by meiosis to produce four spores. This condition is called tetrad. As a result, 64 spores are produced in each sporangium. When the spore develops, the wall of the sporangium ruptures and comes out. The sporophyte stage ends with the formation of spores.
2. Gametophyte stage: The stage of plant life cycle in which gametes i.e. sperm and egg are produced is called gametophytic stage. In sporophyte plants, spores are produced inside the sporangium. The spore is the first cell of the gametophyte stage. Spores germinate in favorable environment to form 4-6 celled protonema. Cells on either side of the protonema divide repeatedly in the process of mitosis to form a green heart-shaped prothallus. Pteris is a companion plant. Flax-shaped archegonia below the anterior groove and spherical or ovoid antheridia below the thallus. Each archegonium produces one ovule and 20-50 spermatozoa in the antheridium. Sperm and egg unite to form a zygote. The gametophyte stage ends with the formation of the zygote.
The zygote germinates under favorable conditions to form the sporophyte. Spores are produced in sporophytes. Spores germinate to form gametophytes. Thus the sporophyte and gametophyte stages appear successively.

Zygote is enveloped by wall and becomes spore. The spore germinates in a favorable environment and divides repeatedly in the process of mitosis to form a new sporophyte.

The ducts of mature archegonium are filled with mucilage and malic acid. The sperm reach the archegonium with the help of rain water or dew drops. Archegonium’s malic acid attracts sperm. Sperm and egg unite. Fertilization results in the formation of a zygote.

Inside the archegonium there are a few cervical duct cells, a ventral duct cell and a large ovule cell. The ovum develops into an ovum.

Inside the antheridium there are 20-50 sperm mother cells or androcytes. Each spermatozoon matures into a multi-flagellated spermatozoon. Spermatozoa break through the cap cells at the top of the antheridium and come out.