THE LIFE CYCLE

THE LIFE CYCLE

1.1-REPRODUCTION

     All living organism produce new individuals of the same spices, that is a new generation of the spices from an existing individual. this fundamental characteristic of living thing is known as reproduction.

     Reproduction is necessary to maintain the number of individuals of a species and to prevent their extinction. 

     organism belonging to the same spices look similar to each other and create new individuals that look like themselves. A basic process in reproduction is the creation of DNA copy. cells use chemical reaction to create a DNA. in this process of copying, some variation take place each time. thus DNA copies generated are similar but not identical to the original.
    
            

                 

THE IMPORTANT IN VARIATION

changes in ecological system, which are beyond our control like varying temperature, varying water level can wipe out a spices. but, if variation in some individual are suitable for new environment, there is chance of survival of that spices.

MODE OF REPRODUCTION

        Two main modes of reproduction are asexual reproduction and sexual reproduction.

ASEXUAL REPRODUCTION

Asexual reproduction is a mode of reproduction by which offspring arise from a single organism, and inherit the genes of that parent only; it is reproduction which almost never involves ploidy or reduction.
                                       
                                        

                                                 


      CLONING
In biology, cloning is the process of producing similar populations of genetically identical individuals that occurs in nature when organisms such asbacteria, insects or plants reproduce asexually. Cloning in biotechnology refers to processes used to create copies of DNA fragments (molecular cloning), cells (cell cloning), or organisms. The term also refers to the production of multiple copies of a product such as digital media or software.
The term clone is derived from the Ancient Greek word κλών (klōn, “twig”), referring to the process whereby a new plant can be created from a twig. Inhorticulture, the spelling clon was used until the twentieth century; the final e came into use to indicate the vowel is a "long o" instead of a "short o".^[1][2]Since the term entered the popular lexicon in a more general context, the spelling clone has been used exclusively.
In botany, the term lusus was traditionally used.^[
In the United States, the human consumption of meat and other products from cloned animals was approved by the FDA on December 28, 2006, with no special labeling required because food from cloned organisms has been found to be identical to the organisms from which they were cloned.^[4] Such practice has met strong resistance in other regions due to misinformation,^[5] such as Europe, particularly over the labeling issue


    SEXUAL REPRODUCTION
Sexual reproduction is a process that creates a new organism by combining the genetic material of two organisms. 


REPRODUCTION IN HUMAN BEING


Human reproduction is any form of sexual reproduction resulting in the conception of a child, typically involving sexual intercourse between a man and a woman. During sexual intercourse, the interaction between the male and female reproductive systems results in fertilization of the woman's ovum by the man's sperm, which after a gestation period is followed by childbirth. The fertilization of the ovum may nowadays be achieved by artificial insemination methods, which do not involve sexual intercourse.
                


  
MALE & FEMALE REPRODUCTIVE SYSTEM

life's internal secrets

life processes 
         Nutrition, respiration, excretion, transportation, reproduction, sensitivity and growth are some of the processes that help the living being to sustain. These processes that are common to all living beings are called as the life processes.
     
Energy for life processes

                 All living organisms require energy to perform various activities. This energy is derived from the food they eat. Thus food is a kind of fuel which provides energy to all the living organisms. Food contains several components called as nutrients. Based on their functions nutrients are divided into three types.

        (1) Energy giving nutrients  -  Carbohydrates, fats(2) Body building nutrients  -  Proteins(3) Protective and regulating nutrients  -  Vitamins and minerals

Heterotrophic nutrition

    Organisms that depend on other organisms for their food are heterotrophic organisms. All animals and fungi are heterotrophs. Different organisms use different strategis to obtain food depending upon their body design, organization, functioning and also availability of food material.

e. g.

1. Fungi like yeast, mushrooms and some carnivorous plants break down the food material into simple substances outside the body and then absorb it.
2. Some organisms take in whole food and then break it down to simple substances inside their bodies and then absorb it. E.g. human being, cat, cow, etc.
3. Some animals and plants derive nutrition from other plants or animals without killing them but during the process they harm the host plant or animal. E.g . cascuta,ticks, lice, leeches, tapeworms etc

  

  Nutrition in human beings

         All the processes involved in nutrition in human beings take place by association of digestive organs called digestive system. The digestive system includes alimentary canal and the digestive glands.

(1) Mouth:

        The alimentary canal beings with mouth. We eat a variety of food items which have to pass through the same digestive tract. Naturally the food has to be processed to generate particles with small size.

        Can you tell which organs of the body are involved in breaking the large food particles into smaller ones?

        Such crushed food is wetted with saliva secreted by the saliva glands so the food can smoothly pass through the soft lining of the alimentary canal. The food that we take is of complex nature. It is converted into simpler molecules with the help of biological catalysts called as enzymes. Enzyme salivary amylase breaks down starch into a simple sugar maltose. Thus digestion starts in the mouth itself.

(2) Stomach:

        The partly digestion food goes down through the oesophagus into a ‘J’ shaped stomach placed on the left side of the abdomen. The food is pushed forward in the canal due to rhythmic contraction and relaxation of the muscles of the canal called as peristaltic movement

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Digestive glands

liver

  

                                                                    villi

stomach

Excretion in human beings

     

           the excretory system in human beings includes a pair of kidney, a pair of ureters, urinary bladder and urethra. kidneys remove the waste products from the blood and urine.

                                                           

  

           Human Excretory System

school of elements

           you are know that matter can exist in the form of elements, compounds and mixtures. when element were discovered scientists adopted different ways to classify them. in earlier days very few elements were known. at that time they were classified as metals and non-metals on the basis of their properties. some elements showed properties of both metals and non-metals and they could not be placed in any of the two classes.to overcome these difficulties, scientists tried to find out some pattern or regularity in the properties of elements.

1.1-Newlands' octaves

       newlands' law states that  "when the elements are arranged in an increasing order of their atomic masses, the properties of the eights elements are similar to the first."

1.2-mendeleeves's periodic table

   the physical and chemical properties of elements are a periodic function of their atomic masses.

        the tabular arrangement of the elements based on the periodic law is called the mendeleev's periodic table.

1.3-modern periodic table

    

classification of elements