Chlorophyll is the green colouring of leaves which are vital to green plants. This helps the plants to make their food. This is also reponsible for the colours in plants such as red in carrots. Plants which have no chlorophyll depend on other plants for food and are called parasites.
Chlorophyll absorbs sunlight and uses its energy to synthesise carbohydrates from CO2 and water. During this process of photosynthesis, chlorophyll produces energy, in the form of carbohydrates, which will power all of the plant's essential growth and development.
Thursday, January 11, 2007
Friday, January 05, 2007
Fungi
Fungi respresent a very important part of the thallophytes, and are distinguished from the rest by many definite charateristics. They have no chlorophyll and no starch is present in their cells. They do not live on their own manufactured food, but rely on decaying plant or animal remains.
The fungi may be single celled plants such as yeast, which is used for baking bread abd brewing beer or can be multicelled such as mushrooms. In these more advanced forms the main part of the plant is an intricate web of threads known as hyhae, the whole web is called mycelium. This often lives underground or inside the host plant on which the fungus is living. The hyphae threads run about either in or between the cells of the plant and have the power of dissolving the cellulose of the cell walls and living on the contents.
The saprophytic ones act in a similar way on dead organic material and are not generally harmful to plants or animals. The parasites on the other hand cause man a great deal of trouble and expense in trying to get rid of them. Some fungi like 'Athelete's foot attack man. With the larger fungi, the hyphae sometimes come above the ground and form a special structure which can produce spores. This is the fruiting stage of the plant and the mushroom and toadstool are examples of this.
The hyhpae have another property which is important to the fungus and this is the formation of hard tuber like body called sclerotium which is capable of exsiting for a long time without growing. This stage makes it difficult to get rid of fungal infections for they can withstand all adverse treatments yet germinate at favourable conditions.
The fungi lack chlorophyll so they absorb carbohydrates from plants or animals on which they live. Like the animals they are dependent on green plants for their food and canot live without them.
The fungi may be single celled plants such as yeast, which is used for baking bread abd brewing beer or can be multicelled such as mushrooms. In these more advanced forms the main part of the plant is an intricate web of threads known as hyhae, the whole web is called mycelium. This often lives underground or inside the host plant on which the fungus is living. The hyphae threads run about either in or between the cells of the plant and have the power of dissolving the cellulose of the cell walls and living on the contents.
The saprophytic ones act in a similar way on dead organic material and are not generally harmful to plants or animals. The parasites on the other hand cause man a great deal of trouble and expense in trying to get rid of them. Some fungi like 'Athelete's foot attack man. With the larger fungi, the hyphae sometimes come above the ground and form a special structure which can produce spores. This is the fruiting stage of the plant and the mushroom and toadstool are examples of this.
The hyhpae have another property which is important to the fungus and this is the formation of hard tuber like body called sclerotium which is capable of exsiting for a long time without growing. This stage makes it difficult to get rid of fungal infections for they can withstand all adverse treatments yet germinate at favourable conditions.
The fungi lack chlorophyll so they absorb carbohydrates from plants or animals on which they live. Like the animals they are dependent on green plants for their food and canot live without them.
What are Bryophytes?
These are the mosses and liverworts. Liverworts are plants requiring damp conditions and they are often found in shade by water or near ditches, where they make green growths on surface of the soil or on rocks. The flattish visible part of the plant is called the thallus and from its underside are produced simple root-like growths which anchor it to the ground.
Most liverworts can increase by sending out branches which eventually become detached from the main plant. They can also reproduce sexually and after the fertilisation of the egg a stalk is produced from the upper surface of the thallus. At the top of the stalk is a capsule containing spores which, when released to fall on a suitable place of growth, will produce a new generation of liverworts.
Most liverworts can increase by sending out branches which eventually become detached from the main plant. They can also reproduce sexually and after the fertilisation of the egg a stalk is produced from the upper surface of the thallus. At the top of the stalk is a capsule containing spores which, when released to fall on a suitable place of growth, will produce a new generation of liverworts.
Wednesday, January 03, 2007
Calenders
A calender is just a way to keep track of time. The 'Gregorian' calender is most used these days. In Indian history, we have used different types of calenders. For business and government purposes we use the 'Gregorian' calender but, when its time to celebrate holidays like Pongal and Eid other calenders are used.
The Islamic calender is a lunar calender. The lunar month is roughly the time moon takes to go around the earth. The Islamic Lunar calender is shorter than the 'Gregorian' calender by 11 days. This means that the month of Ramzan will be observed around 11 days earlier every 'Gregorian' calender.
Emperor Akbar used a combination of the Hindu and Muslim Calender. This calender counts dates begining with the birth of Christ as A.D and counts dates before the birth of Christ as B.C. These days, many modern historians use the letters C.E (common era) instead of A.D and letters B.C.E instead of B.C.
The Islamic calender is a lunar calender. The lunar month is roughly the time moon takes to go around the earth. The Islamic Lunar calender is shorter than the 'Gregorian' calender by 11 days. This means that the month of Ramzan will be observed around 11 days earlier every 'Gregorian' calender.
Emperor Akbar used a combination of the Hindu and Muslim Calender. This calender counts dates begining with the birth of Christ as A.D and counts dates before the birth of Christ as B.C. These days, many modern historians use the letters C.E (common era) instead of A.D and letters B.C.E instead of B.C.
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