Change In Seasons - Why Season Changes?

We experience different types of seasons round a year. Chiefly, they are summer, autumn, winter and spring. As you have experienced, it is quite hot in summer (June-August) but it is quite cold in winter (December-February). But it is neither hot nor cold in spring (March-May) and in autumn (September-November). We need layers of very warm clothes in winter but we get sweat pouring off even with very light cotton clothes in summer. Everyone

Modification of Leaves-Leaf tendrils, Leaf spines, Leaf scale, Phyllode, Pitcher, Bladder

The leaf can be defined as a lateral outgrowth of the stem arising from the node and having a bud in its axil. Leaves are flat, green in color due to the presence of chlorophyll. Leaf helps to manufacture food for the whole plant body. Besides their normal function of photosynthesis, gaseous exchange and transpiration,

Modification of Stem - Underground, Sub aerial and Aerial Modification

The stem is the aerial portion of the plant axis which develops from the plant plumule of the embryo. It is differentiated into node and internode. Stems grow erect above the soil and towards light performing their normal functions like support, protection, storage of food and photosynthesis. Broadly, there are three types of modifications in the stem: underground modifications, sub-aerial modifications and aerial modifications.

Photosynthesis - Process, Required Raw Materials and Products

Green plants can manufacture their own food. They prepare food not only for themselves. The food is utilized by all animals and plants which cannot manufacture their own food. Green plants contain chlorophyll which is green pigment. Chlorophyll can trap sunlight. Green plants prepare food with the help of raw materials like carbon dioxide (CO₂) and water (H₂O) in the presence of sunlight. The food prepared by the plants is stored in the

Modification of Roots - Tap and Adventitious root Modification and Examples

The part of the plant which develops from the radical part of the seed and does not bear any leaf, bud or flower is known as root. it is non-green and grows downward in the soil. In addition to the normal functions of fixation, absorption and conduction performed by the roots, the root may perform additional functions of storage, additional support or vital functions of assimilation, respiration and others. In order to perform these specific

Seed - Function, Structure and Types

A seed is a reproductive part of a flower. It is developed from a fertile ovule. It encloses embryo and stores food for its development. A seed is the ripened ovule which contains an embryo and its food source is covered by a protective coat. Seeds are the product of the ripened ovule, after fertilization by pollen and some growth within the mother plant. Under suitable conditions seed germinates and gives a baby plant. 

Fertilization - Full Process

After pollination on the stigma pollen grains start forming a pollen tube. The pollen tube pierces through tissue of the style and reaches the ovule in the ovary. Generally, the tip of the pollen tube enters the embryo sac of the ovule through micropyle. The pollen tube releases two male gametes. One of the male gametes fuses with the egg cell forming a diploid zygote or oospore. This fusion of male and female gamete is called fertilization. 

Pollination and Its Types and Differences

The process of transfer and deposition of pollen grains from an anther of a flower to the stigma of a carpel of the same or another flower is known as pollination. This process is achieved in different ways, but the method of pollination is different in different species. Pollination is generally of two types: self pollination and cross pollination. When the pollen grain is transferred from anther to the stigma of the same flower, it is called self pollination

Flower and Its Parts

The flower is a highly specialized and colorful part of shoot of limited growth. It is concerned with the sexual reproductive process in higher plants leading to the formation of fruits and seeds. Flower is the reproductive structure found in flowering plants. The function of a flower is to affect reproduction, usually by providing a mechanism for the union of sperm with eggs. Flowers may be complete or incomplete. Hibiscus, mustard, etc

Fungi - Occurence, Structure, Characteristics, Importance, Reproduction and Control of Fungal Growth

Fungi are a group of non-green plants such as yeasts, moulds, mushrooms, etc. They do not contain chlorophyll and hence they cannot manufacture their own food. Fungi are either saprophytes or parasites. Saprophytic fungi feed on decaying organic material of dead organism. Parasitic fungi obtain their food from the tissues of living plants and animals. Fungi are unicellular or multi-cellular. The bodies of fungi are not differentiated

Virus - Characteristics, Structure, Classification, Mode of Transmission of Viral Diseases and Control of Viral Diseases

The word virus is derived from Latin word ‘viron’ which means ‘poison’. Virus is the smallest entity, which is parasitic, ultramicroscopic and disease producing organism. Virus multiplies only inside the living cells of plants and animals and for this reason, is called obligatory parasite. In non-living virus is inactive but it becomes active if it infects a living cell. It multiplies in a living cell and cause many diseases in living organism. Thus, virus is

Bacteria - Characteristics, Occurrence, Size, Shape, Structure, Importances and Control of Bacterial Diseases

Bacteria are the most primitive, simplest and the smallest, unicellular, microscopic organisms. Bacteria were first discovered by Antony von Leeuwenhoek in 1676 A.D. He observed them in a drop of rainwater with the help of a self constructed microscope and called them little animalcules. In 1838 AD these little animalcules were given the name bacteria by Ehrenberg and in 1854 AD they were classified as plants by Cohn.

Asexual Reproduction - Types, Advantages and Disadvantages

Reproduction is the most important characteristics of all living organisms. It is not beneficial for an individual but is essential for the continuity of life from one generation to the next generation. Thus, reproduction is the process which helps all living organisms to increase in number by producing young ones of their own kind. There are two types of reproduction. They are asexual reproduction and sexual reproduction. Today we are going to discuss

Plant Tissue - Types, Characteristics, Occurence and Function

The higher plants have multicellular bodies made up of various kinds of cells. These cells cluster together to perform specific functions. A group of plant cells having common origin and similar in structure and function is known as plant tissue. Most of the plant tissues are dead. Most of the tissues in plants are supportive, need less energy and maintenance. The growth of plant is indefinite. Plants grow throughout their life with the help of certain tissues

Animal Tissue - Types, Characteristics and Function

We know that the body of animals is made up of different types of tissues which perform specific functions. For example; contraction and relaxation of muscle cells result in the movement of body parts. Blood and lymph carry substances from one part to another part of a body. Nerve cells respond to external and internal stimuli. Thus, muscle, blood, nerve, etc are the examples of tissue found in our body. A group of animal cells having the same

Some of the Reasons for Origin of the Organisms on Earth

The estimated age of the earth is 4.5 billion years. When the earth was formed the temperature, pressure and environmental conditions were not appropriate for the life. Billions of years were taken by the earth for stabilization and maintenance of appropriate climate. Earth from the gases state changed into molten state and slowly solidified. Later atmosphere was formed. From the combination of hydrogen and oxygen rainfall occurred.

Some Hypothesis About the Origin of the Earth

It is curious to know about the formation of universe and our solar system. Numerous questions about the formation of himalayas, mountains, rivers, vegetation, oceans, etc on earth is another curiosity. Many scientists have tried to explain about the origin of the universe and solar system including our earth. Some scientists believe that our earth was formed from a big star. Other group of scientists believes that earth was evolved from the

Acid Rain - Causes, Effects and Control Measures

Acid rain is the precipitation or deposition of some industrial gases when come in contact with water having a pH lower than 5.6. It is caused by process of reaction of industrial gases with water in the atmosphere. Simply acid rain can be defined as a rain with a pH less than 5.6. Acid rain or acid deposition is a broad term that includes any form of precipitation with acidic components such as sulphuric or nitric acid that fall to the ground from the

AIDS - Causes, Symptoms, Modes of Transmission and Preventive Measures

AIDS is a sexually transmitted fatal disease. AIDS was first described in medical literature in 1981 in homosexuals and hence, the diagnosis of the first case. It is one of the most serious communicable disease at present time. It is a viral disease that disrupts the immune system of the body. In 2018, around 770,000 [570,000-1.1 million] people died from AIDS related illnesses worldwide. It has a large impact on society, both as an illness and as a source of

Cancer - Causes, Symptoms and Preventive Measures

Cancer may be defined as an active and uncontrolled proliferation of the cells of all types in any site or any tissue of the body leading to death if early detection and treatment is not done. Cancer cells have a very great invasive property. Cancer may affect an organ but the most common sites of cancer are the lungs, the breast, the uterus, the urinary bladder, the