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.

Molecular Theory of Magnetism - Facts about Molecular Theory

The theory was first propounded by Weber in 1852 AD and was later developed by Ewing in 1890 AD. Due to this fact, it is also known as Weber Ewing theory. According to this theory, every magnetic substance contains a very tiny magnet called molecular magnet. In a magnetized piece of iron, molecules are present in all possible direction and form (closed chains) random orientation and the result is that one molecular magnet cancels

Neil Armstrong - Biography

Neil Armstrong was born on August 5, 1930, on a farm near Wapakoneta in the western Ohio, USA. He took his first airplane ride at the age of 6. He was fascinated with aviation, so he started to build model aeroplanes and conducted experiments in a homemade wind tunnel. As a boy, he worked at a pharmacy and took flying lessons. He was licensed to fly at 16, before he got his driver’s license. He always paced ahead, not back. He is known

QBASIC Programming-Elements, Features, Statements. Learn QBASIC within few minutes...

QBASIC is a high level computer language published by Microsoft which stands for Quick Beginners All Purpose Symbolic Instruction Code. QBASIC environment includes a full screen syntax checking, multi-file and multi-window editing, full debugging facilities, pull-down menus, syntax-checking editor and a simple yet a powerful menu structure that can be driven through either by a keyboard or a mouse. Once you are in the QBASIC

Teddy Stoddard and his Teacher-Who Make A Difference? An Inspiring Story

On her very first day of teaching, Mrs. Thompson stood in front of her class. Then she told her students that it was untruth that she loved them equally. Perhaps, it was impossible. In the class, she saw a messy small boy named Teddy Stoddard slumped in his seat. He was untidy in his get up and messy in his figure. He did not play well with others. Mrs.

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

Low Blood Pressure - Causes, Symptoms and Preventive Measures

The blood pressure less than 130 (systolic)/85 (diastolic) mmHg (according to American Heart Association) is normal blood pressure in adults. On an average it may be 120/80 mmHg. But when the pressure decreases than the normal it is explained as a low blood pressure. Low blood pressure, medically known as ‘Hypotension’ is generally considered as systolic blood pressure of 90 mmHg or less in adults. Blood pressure varies, depending on

High Blood Pressure - Causes, Symptoms and Preventive Measures

According to American Heart Association, high blood pressure (medically known ‘Hypertension’) means systolic blood pressure is consistent at 140 or over 140 or diastolic blood pressure is consistent at 90 (140/90 mmHg). High Blood Pressure is a serious problem because people with this condition have a higher risk for heart disease and other medical problems than people with normal blood pressure. If left untreated, high blood

Heart Attack - Causes, Symptoms and Preventive Measures

Heart attack, also known as myocardial infarction (MI), generally occurs when the supply of blood and oxygen to an area of heart muscle is generally blocked, usually by a blood clot. This may cause to the heart to stop beating and from pumping blood effectively and leads to death or permanent damage to the heart. A heart attack, or myocardial infarction (‘Myo’ means muscle, ‘cardial’ refers to the heart and ‘infarction’ means death o tissue due to lack