What is an Ecosystem?

What is an Ecosystem?

Hi viewers: Today we will discuss about the ecosystem.  First of all let us check out the meaning of ecology. Eco has come from the Latin word Oikos, which means Home and Logy means Study.  Here home is referred to our nature.  So the study of home is known as Ecology. Ecosystem Hello viewers, Today we will touch upon a very important and interesting topic.  We will talk about ecosystem, the different types of ecosystems, food cycle, energy flow and so on.  Let me define it first and then we will move into the details and explain each step by step. Definition of Ecosystem: An ecosystem is a natural ecological unit consisting of biotic and abiotic components, the interaction among which results in a table and self-perpetuating system.   Population or biological population: It is the association of individual members of the same species living together in a particular locality. Community or biotic community: It consists of several populations living in association in a given area. Biome:...
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What is Adaptation?

What is Adaptation?

Adaptation Hello viewers, Today we are going to talk about another very important and interesting topic and that is Adaptation.  We will go through the definition first and then explain each aspects of it in details.  So let's get started. What is adaptation? Definition Adaptation is the mode of adjustment by the living organism, to the surrounding environment through morphological and physiological changes. Explanation All living organisms have to struggle for existence for their survival the struggle is always against the difficulties and odds present in the environment.  Only they can survive which have advantageous variation such variation ultimately lead to adapted features.   Aims-  Adaptation enable an individual to struggle well for existence thus the adapted one are only selected by nature for survival.   Adaptation in lotus:  Lotus is a partially submerged plants. Root: The root system is very ill developed and hence roots are scanty in number The roots do not carry any root cap. Stem: Stem is an underground rhizome. The stem carries adventitious root. Leaves: The petiole is very...
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Theory of evolution by Natural Selection

Theory of evolution by Natural Selection

Hello viewers, Today we are going to talk about the evolution by natural selection by Charles Darwin, which is a very interesting and fascinating topic and there is so much to talk about.  We will start with the definition first and then go into the detailed explanation of the topic.  So let's get started... Definition of evolution: Organic evolution is a slow and gradual process of change through, which higher forms of living organisms are produced from the pre-existing lower forms by means of speciation. Origin of life There are several theories put forward to explain the probable way of origin of life.   Devine theory: It states that the first life was created by God as it could not be proved experimentally it is not universally accepted. The theory of cosmic origin: It states that the first life was brought from some where in outer cosmos.  Due to lack of experiment support this is also not accepted. Theory of biochemical origin: It states that the...
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Hormones

Hormones

Hormones Hi viewers: Today we will discuss a very important topic of biology, which is Hormones.  Now let us check out the meaning of Hormones from its definition cited below Definition Hormones are special types of organic compounds that are secreted from the special cell (plants) or from the endocrine glands (animals) and act in the role of chemical messengers to maintain co-ordination in living organism. Plant hormone or phytohormone As the plant has no nervous system the co-ordination is mainly maintained by the hormones various types or hormones are secreted in the plant.   Properties of hormones: Hormones work individually in very low concentration. It acts as a catalyst. Hormones cannot act on those cells from which they are secreted but act a site remote from their place of production after being transported through the conducting systems. They are generally protein in nature and never stored in any other place for future use except the secreting glands or tissues. But some hormones like adrenal corticohormones are steroid...
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Growth and Reproduction in Plants and Animals

Growth and Reproduction in Plants and Animals

Growth and Reproduction Today we are going to discuss another interesting topic and that is growth and reproduction in plants and animals.  We will go through the different influencing factors and internal factors that play a role in growth and reproduction is detail below and we will start with the definition of growth first.... Definition:  Growth is a permanent and irreversible increase in size, form or volume of a living organism and is always attend by an increase in weight.   Method of growth- Growth can be achieve by three principal methods. Increase in number of cells produce through cell division. Proliferation of the intercellular spaces. Increase in volume of cell.   Rate of growth:  When the amount of growth is expressed per unit time is called rate of growth it is generally slower in plant than the animals. If the amount of growth is graphically plotted against time, a sigmoid curve is obtained.  If this growth rate curve is examined three phases are found. Lag period:  At...
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Heredity Inheritance and Variation of Traits

Heredity Inheritance and Variation of Traits

Heredity Inheritance and Variation of Traits Hello viewers, Today we are going to discuss about another important chapter which is heredity inheritance and variations of traits in living organism.  So as we always do, we will start with the definition first and then we will go deeper in the details of it.  So let's get started..... Mendel’s work containing his discoveries was first published in the year 1866 in an ordinary journal, “Brunn Society on Natural Science” in the name “Experiment in plant hybridization”.  But his contribution remained unnoticed until 1900, when his laws were rediscovered by three European botanist – Hugo De Vries of Holland, Carl Correns of Germany, and Enrich Von Tschermak of Austria.   Heredity Inheritance and Variation It is the mode of transference of characters from the parents to the offsprings or from one generation to another.   Genetics:  The branch of science concerned with heredity. a. Heredity: The mechanism by which the physical, mental etc. characteristics of parents are transmitted from one generation to...
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Meiosis Cell Division

Meiosis Cell Division

Hi Viewer: Today we will discuss another very important cell function, which is known as Meiosis Cell Division.  Meiosis cell division do occur in plant cell and as well as in animal cell.  Living organisms produce gametes by this process.  It is very complicated too.  So let us check out what happens in the process, which is described below. Meiosis  Definition: Meiosis is the germ mother cell division in which the chromosome number of the mother cell is reduced to half in each daughter cell (reductional division). Site of occurrence:  In plant meiosis occurs in the microspore mother cell and megaspore mother cell and in animal it occurs in the germ mother cell of the testis and ovary.   PROPHASE 1 Leptotene (lepto-thin/tene-band): Chromosomes start to dehydrate It appears as distinct longitudinal threads 4.  Each chromosome has a beaded appearance 5.  The appearance is for the chromomeres 6.  In some insects the chromosomal ends are arranged in a particular direction. This is called a bouquet stage. N.B.   Draw two centrioles...
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