Category: Biology Second Paper Lecture Sheet

The class of herbaceous plants is Magnoliophyta. Magnoliophyta are divided into two classes. Magnoliopsida and Liliopsida.
1. Magnoliopsida: Magnoliopsida consists of 7 sub-classes, 56 classes and 315 genera. The sub-classes are:
(i) Magnolidae: The class number of Magnolidae is 7.
(ii) Hamamelidae: Class number of Hamamelidae is 8.
(iii) Ranunculidae: The class number of Ranunculidae is 3.
(iv) Caryophyllidae: The class number of Caryophyllidae is 3.
(v) Dillenidae: The class number of Dillenidae is 12.
(vi) Rosidae: Class number of Rosidae is 16.
(vii) Asteridae: Class number of Asteridae is 7.
2. Liliopsida: Liliopsida consists of 4 sub-classes, 20 classes and 65 genera. The sub-classes are:
(i) Alismatidae: Class number of Alismatidae is 3.
(ii) Lilidae: Class number of Lilidae is 3.
(iii) Arecidae: The class number of Arecidae is 5.
(iv) Commelinidae: The class number of Commelinidae is 6.

1. Herbaceous plants are shrubs, trees and shrubs. Some plants are parasitic or parasitic in nature. Siddique Publications
2. The main plant body is the sporophyte. They are of the most advanced nature.
3. Plant bodies can be soft or hard, woody or non-woody, evergreen or deciduous, annual or perennial.
4. They are flowering plants. The flowers of the plant are solitary or in panicles.
5. They are vascular plants. Vascular bundles are connected and anterior. Free and Equilateral or Equilateral.
6. The uterus is divided into uterus, uterus and cervix.
7. The germinated pollen grains fall into the ovary.
8. Their uterine chambers are special. Ovulation is produced in it.
9. The seeds are enclosed inside the fruit.
10. Seeds contain one or two carpels.
11. Their spermatozoa are non-flagellate and motile.
12. They are bisexual.
13. Their seeds are triploid and produced after fertilization.
14. Xylem contains vessels and phloem contains cells.
15. They do not produce archegonia, so are advanced in nature.
16. Gametophyte is very short and dependent.
17. The life cycle has a clear sequence.
18. 120 kinds of modern and valuable medicines are prepared from more than hundred species of plants.

The world’s smallest herbaceous plant is Wolffia microscopy. Its length is 0.1 mm or 300-600 micrometers and weight is 150 micrograms. The tallest herbaceous plant is Eucalyptus marginata. Its height is 500 feet. It is found in Tasmania, Australia. The smallest herbaceous plant of Bangladesh is Wolffia arrhiza (duckweed). There are 2,87,000 species of plants in the world. However, the number of species in Bangladesh is about 5000.
Herbaceous plants are believed to have originated in the Cretaceous period 13 million years ago. The first herbaceous plants originated in tropical regions, particularly Southeast Asia. Spread in different directions within 4-5 crore years. No fossils of herbaceous plants have been found till date.

The word Angiosperm is formed from the Greek words Angeion meaning vessel or darkness and spermos meaning seed. The word Angiosperm means angiosperm. Plants that have flowers, seeds, and seeds enclosed in fruits are called herbaceous plants. Herbaceous plants are flowering plants.

1. Food: The succulent young stems and seeds of Cycas are used as vegetables. Sago is made from its seeds in Japan. Indum podi flour is made by grinding their seeds. Indum podi flour is used to make cakes and other dishes.
2. Ornamental Plants: Cycas are planted as ornamental plants in gardens, courtyards, roadsides and courtyards.
3. Medicinal use: Young leaves of Cycas are used in stomach ailments and skin diseases.
4. Mat Making: Mats are made from Cycas leaves.
5. Winemaking: The stem pulp of Cycas is used to make wine.
6. Causes disease: t Causes Lytico-boding disease. The symptoms of this disease are similar to those of Parkinson’s disease.
7. Traditional Uses: In many places cycads are important in religious and social customs.

1. Ovulation: The megasporophylls of Cycas are united to form a crown. The upper part of megasporophyll is called pinnule. At its base are 2-4 pairs of large and red ovules. The megasporophyll with the ovule looks like a snake’s hood. It is called Sarpamani. Inside the ovum are the female cells. Spore mother cells divide by meiosis to produce megaspore. Archegonia are formed from the female sperm. Ovules develop inside the archegonium.
2. Fertilization: Anthers are formed from the cymes of Cycas. Fertilization of sperm and egg occurs inside the anther. Fertilization results in the formation of a zygote.
3. Seed Formation: Embryo is formed from zygote. The embryo divides and becomes a seed. Cycas seeds are juicy, orange or red in color.
4. New Plant Formation: Cycas seeds germinate and produce new plants.

The spores of Cycas are airborne and fall on the ovules of the female plant. Anthers or pollen tubes are formed from the protozoa. Sperm are produced inside the anther. Sperm and egg unite to form zygote. Zygote develops into seed. The seeds are juicy, orange or red in color. The seed germinates and produces a new plant.

The megasporophylls of Cycas are leaf-like, hairy and brown in colour. Together they form the crown. The upper part of megasporophyll is called pinnule. At its base are 2-4 pairs of large and red ovules. The megasporophyll with the ovule looks like a snake’s hood. It is called Sarpamani (sold as Sarpamani in the market). Inside the ovum are the female cells. Spore mother cells divide by meiosis to produce spores or megaspores. Archegonia are formed from the female sperm. Ovules develop inside the archegonium. Archegonium is the original characteristic of Cycus.

Cycas plants have spike-shaped strobilus at the apex (50 cm). Stamen strobilus is surrounded by numerous sporangia or microsporophylls. Microsporophylls are 3-5 cm long and 12-23 mm wide. The microsporophylls are spirally and densely arranged. It is flat, thick and scaly. Its base is narrow and its tip is wide. Anteriorly there is a triangular apophysis. Each microsporophyll contains numerous sporangia. 2-5 sporangia together form a sorus. Inside the sporangium is the spore mother cell. Each spore mother cell divides by the process of meiosis to produce spores or microspores. Microspores produce sperm. Spermatozoa of Cycas are Latim-like, multi-flagellated and the largest in the plant kingdom.

Cycas are dioecious and unisexual plants. Their male plants produce spores or microspores and female plants produce spores or megaspores. Microspores are located in microsporophylls and megaspores are located in megasporophylls. The microsporophylls together form the strobilus or staminate or cone. Megasporophylls form a crown without forming a strobilus.
(i) Microsporophyll: Cycas plants have spike-shaped strobilus at the apex (50 cm). Stamen strobilus is surrounded by numerous sporangia or microsporophylls. Microsporophylls are 3-5 cm long and 12-23 mm wide. The microsporophylls are spirally and densely arranged. It is flat, thick and scaly. Its base is narrow and its tip is wide. Anteriorly there is a triangular apophysis. Each microsporophyll contains numerous sporangia. 2-5 sporangia together form a sorus. Inside the sporangium is the spore mother cell. Each spore mother cell divides by the process of meiosis to produce spores or microspores. Microspores produce sperm. Spermatozoa of Cycas are Latim-like, multi-flagellated and the largest in the plant kingdom.
(ii) Megasporophyll: The megasporophylls of Cycas are leaf-like, hairy and brown in colour. Together they form the crown. The upper part of megasporophyll is called pinnule. At its base are 2-4 pairs of large and red ovules. The megasporophyll with the ovule looks like a snake’s hood. It is called Sarpamani (sold as Sarpamani in the market). Inside the ovum are the female cells. Spore mother cells divide by meiosis to produce spores or megaspores. Archegonia are formed from the female sperm. Ovules develop inside the archegonium. Archegonium is the original characteristic of Cycus.
(iii) Fertilization: The spores of Cycas are airborne and fall on the ovules of the female plant. Anthers or pollen tubes are formed from the protozoa. Sperm are produced inside the anther. Sperm and egg unite to form zygote. Zygote develops into seed. The seeds are juicy, orange or red in color. The seed germinates and produces a new plant.
The ovules are arranged on both sides at the base of megasporophyll of Cycus. The megasporophyll with the ovule looks like a snake’s hood. It is called Sarpamani. In various places, snake gems are sold as medicine for all diseases. Actually it has no medicinal properties. As a result common people are being cheated or deprived.