The Living World Notes

The Living World 

           

Life is the condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death.

Life is a characteristics quality that differentiates an inanimate(non_livings)objects from the animate(living) forms.

CHARACTERISTICS EXHIBITED BY LIVING ORGANISMS –

Growth,
Reproduction,
Ability to sense environment and mount a suitable response,
Metabolism,
Ability to self-replicate,
Self-organise,
Interact and
Emergence.

1. Reproduction process of producing young ones by living things.

                     Asexual Reproduction  do  not  invovle the fusion of gametes or sex cells , e.g, Amoeba
                     Sexual Reproduction  Invovles the fusion of gametes, e.g.,humans

2. Consciousness​   the state of being aware of and responsive to one's surroundings & ability of an organism to sense their environment.

3. Adaptation   Adaptation, in biology, process by which an animal or plant species becomes fitted to its environment.
                            Short Term Adaptation   Temporary changes to responds to changing environment.                                                                       e.g, hibernation and aestivation
                            Long Term adaptation permanent changes in response to changing environment,                                                                          e.g., humming birds

4. Metabolism the chemical processes that occur within a living organism in order to maintain life.

                                 Catabolism involves all of the metabolic processes that tear down biomolecules,
                                 Anabolism is all of the metabolic processes that build biomolecules

5. Thermoregulation Process of regulation body temperature.
                                                       Heat stroke  Increase in body temperature above normal level
                                                       Hypothermia  decrease in body temperature below normal level

​BIODIVERSITY   

Biodiversity the variety of plant and animal life in the world or in a particular habitat, a high level of which is usually considered to be important and desirable. Biological diversity encompasses microorganism, plants, animals and ecosystems such as coral reefs, forests, rainforests, deserts etc

SYSTEMATICS

In biology, systematics is the study and classification of living things; in other words, grouping organisms based on a set of rules (or system).

Two Kinds of Systematics :-Systematics can be divided into two closely related and overlapping levels of classification:

taxonomic (known as the Linnaean System) and phylogenetic.

Taxonomic classifications group living things together based on shared traits - usually what they look like or what their bodies do. For example, animals that lay eggs and have scales we call reptiles, and animals that have live births and have fur or hair we call mammals.
Phylogenetic classifications use the taxonomic names, but further group organisms by how evolutionary related they are to one another.
It is study of the units of the biodiversity, It attempts to classify the diversity of organisms on the basis of following four fields viz,
identification. classification, nomenclature and taxonomy.

​Identification It aims to  identify the correct name and position of an organism in the already established classification system It is done with the help of Keys. Key is a list of alternate characters. An organism can be identified easily  by selecting and eliminating the characters present in the key.

Classification  It involves the scientific grouping of identified organism into convenient categories or taxa based  on some easily observable and fundamental characters.

The various categories are kingdom, phylum,class, order, family, genus and species.

Nomenclature After classification, organism are subjected to a format of two-word naming system called binomial nomenclature. It consists of two components, i.e., generic name and specific epithet 

• For example,  in Mangifera indica, 'Mangifera' is the generic name and 'indica'  is the specific name of mango. This system was proposed by C Linnaeus (a Swedish Botanist) in (1753) in his book Species Plantarum.
• An organism is known by different names in different languages. It would be impossible for any person to remember the names of an organism in all the languages. Hence, there is need for a uniform system of nomenclature of organisms. A uniform system of nomenclature and identification helps the scientists in systematic study of living beings. ICBN (International Code for Botanical Nomenclature) applies to the plants and ICZN (International Code for Zoological Nomenclature) applies to the animals.

• General Rules for Nomenclature:

• Biological names are usually written in Latin. They are written in italics.
• A biological name usually contains two terms. The first term shows the genus, while the second term shows the species.
• Biological name is underlined, when it is handwritten.
• The first term of the biological name begins with a capital letter. The second and the subsequent terms begin with the small letter.                  

           Codes for Biological Nomenclature    

      
             5 codes of nomenclature which helps to avoid errors, duplication and ambiguity in scientific names.

                                      These codes are as follows

                   ICBN    INTERNATIONAL CODE OF BOTANICAL NOMENCLATURE
      ICZN    INTERNATIONAL CODE OF ZOOLOGICAL NOMENCLATURE
      ICVN    INTERNATIONAL CODE OF VIRAL NOMENCLATURE
      ICBN    INTERNATIONAL CODE OF BACTERIOLOGICAL NOMENCLATURE
      ICNCP INTERNATIONAL CODE OF NOMENCLATURE FOR CULTIVATED