Flora: Flora refers to the total number of plants found in a particular area at a particular time.
Fauna: Fauna refers to the total number of animals found in a specific region at a particular time.
Vegetation: It is a broad term used for the plant forms of a region. It does not have any particular taxa or botanical characteristics.
Organism: An organism may be defined as a form of life composed of mutually interdependent parts that maintain various vital processes. The basic and fundamental unit of life is a cell, Hence the form of life in the form of an organism may range from Unicellular to Multicellular entity.
Unicellular organisms are those entities that exist in the form of a single cell and include Bacteria, Archaea, Protozoa etc. the multicellular organism exists in the form containing many cells all of which works in coordination with each other and includes Algae, Fungi, Plants, and Animals, etc.
Biology is the science of life forms and living processes. The living organisms interact with one another as well as with their physical and chemical environment. The term biology was introduced by G. R. Treviranus and Lamarck (1802). The living organisms occur almost in every habitat on earth. All living beings share certain unified and basic characteristics. These include organization, energy utilization, regulation or homeostasis, growth, development, reproduction, and adaptation
1. Growth: All organisms possess the ability to grow. An increase in mass and number of individuals are essential for the growth of the living organism. The growth of multicellular organisms occurs due to cell division. Cell division occurs in plants throughout their life but in animals occurs and stops after a certain period of time. But certain organs of the animal body replace cells throughout the life of an organism such as skin cells, etc. Not only multicellular organisms but unicellular organisms grow via cell division.
2. Reproduction: Reproduction is another characteristic of living organisms. Reproduction is the ability to produce offspring either similar to parents such as in the case of the asexual mode of reproduction or partially similar to their parents such as in the case of the sexual mode of reproduction. Apart from sexual and asexual modes of reproduction, some organisms such as Planaria, reproduce by regeneration. But there are certain organisms that do not reproduce such as mules, sterile worker bees, etc.
3. Metabolism: Every organism is made up of different chemicals which are synthesized and degraded throughout the life of an organism according to the need of the body. There are many metabolic reactions occurring in the living organism. It includes both catabolic (breakdown complex compound into the simpler form) and anabolic (simpler molecules combined to form complex compound) reactions. Microbes, fungi, plants, and animals undergo metabolism.
4. Cellular organization: Cellular organization is the defining feature of all characteristics of organisms.
5. Response to the external stimuli: Living organisms are able to respond to external stimuli which can be physical, chemical, or biological. Human organisms are the only organism that possesses self-consciousness.
Living organisms are made up of many types of inorganic as well as organic biomolecules. Inorganic compounds include water, minerals, etc. which are always micromolecules (small-sized, low molecular weight, readily soluble in water and diffusible) while organic molecules may be micro (e.g., monosaccharides, amino acids, vitamins, etc.) or macro-molecules (large-sized, high molecular weight, insoluble or slightly soluble and non-diffusible e.g., Polysaccharides, proteins, fats, nucleic acids, etc.). These molecules are also known as biomolecules as they are produced by and exist in living organisms. Both types (Inorganic and organic) of biomolecules play important roles in metabolism.
Role of Water: Water forms 70-90% of the cellular pool. It forms 65% (about two-thirds) of the human body. It is formed of H and O in the ratio of 2:1. 95% of water is found in a free state and 5% in combined form in the cell. Water helps in sustaining life processes.
Role of Oxygen: Oxygen is mainly utilized in aerobic respiration of the nutrients inside the mitochondria to produce energy-rich ATP molecules, so it is essential for life. In the absence of oxygen, only 5% of energy available is released.
Role of Carbohydrates: Carbohydrates are organic compounds formed of C, H, and O generally in the ratio of 1:2:1. These are commonly called saccharides (Gk. saccharon = sugar). Carbohydrates are the main storage molecules and most organisms use carbohydrates, as an important fuel, by breaking these bonds and releasing energy to sustain life.
Role of Proteins: Proteins are polymeric compounds formed by the interlinking of amino acids (monomers) by peptide bonds. Out of about 100 types of amino acids, only 20 types of amino acids. Proteins play a vital role in the formation of structures in living organisms. Like carbohydrates and fat, protein can be broken down with the release of energy. Protein is not stored as such in the body and it is only used as a substantial source of energy in conditions of starvation.
Role of lipids: Lipids comprise a major group of insoluble hydrocarbons having many functions. These are polymers of alcohols (e.g., glycerol) and fatty acids interlinked by ester bonds. Complex lipids such as true fats are important organic molecules that are used to provide energy.
Role of Nucleic acid: These are polymers of nucleotides interlinked by phosphodiester bonds called polynucleotides. Each nucleotide is formed of 3 components: a pentose sugar (e.g., ribose in RNA and deoxyribose in DNA), a phosphate group, and an inorganic nitrogen-base (a purine or a pyrimidine). DNA acts as genetic material in most organisms and controls the synthesis of structural and functional proteins. RNA also acts as genetic material in all plant viruses e.g., TMV, and helps in protein synthesis.
There are about 1.7 to 1.8 million known species. The variety of species inhabiting a geographical niche is known as Biodiversity. Different organisms have different names according to the region. So, to solve the problem and to give one organism one name, scientists had decided to give one scientific name to each organism. This process of naming is known as nomenclature. Principles and criteria were given for naming the organisms, by scientists known as the International Code for Botanical nomenclature (ICBN) for plants and the International Code of Zoological Nomenclature (ICZN) for animals. This helps the scientist from all over the world to interact with each other using the same name. Each name consists of two parts, the first part is the generic name or genus followed by the genus name. This is known as Binomial Nomenclature. This was given by a scientist known as Carolus Linnaeus. There are certain rules for nomenclature-
Biological names are in Latin and written in italics.
The first word represents the Genus and the second represents the species.
Both the words, that is, genus and species name should be underlined and should be in italics.
The first-word genus starts with a capital letter and the second-word species starts with a small letter. For example, mango is written as Mangifera indica
the name of the author comes after the species name.
In order to study all organisms in a simple way, scientists have proposed a system of classification. Classification is the process of grouping organisms based on observable characteristics. Organisms are also classified based on the taxa. This type of classification is known as taxonomy. Taxa (singular taxon) are defined as the group of organisms or populations presented as the same unit based on some characteristics. The study of different kinds of organisms and their relationships is known as systematics, which includes classification, nomenclature, and identification of different kinds of organisms. It also gives information about the evolutionary relationship among different organisms.
The Classification includes a hierarchy of steps that represents rank or a category. the overall taxonomic arrangement is known as the taxonomic category and all categories together form a taxonomic hierarchy.
Taxonomic studies of all known organisms had led to the development of common categories such as kingdom, phylum, class, order, family, genus, and species.
Species: Group of individuals or a population that is capable of interbreeding is known as species. Species are classified based on some fundamental similarities.
Genus: It represents a group of related species which share one or more characteristics in common. It can also be defined as the aggregates of closely related species.
Family: It includes a group of related genera but with fewer similarities with genus and species. In the case of plants, the family contains both vegetative and reproductive features. For example, Datura, Solanum, and Petunia are placed in a family known as Solanaceae.
Order: It is the assemblage of families with only a few similarities. For example, Convolvulaceae and Solanaceae are placed in order Polemoniales.
Class: Related orders are included in the class. For example, class Mammalia includes order Primata along with order Carnivora.
Phylum: Different classes combine to form phylum. Fishes, amphibians, reptiles, birds, and mammals are placed in the phylum Chordata. They are placed in Chordata as they possess some common features such as the presence of notochord and dorsal hollow neural system.
Kingdom: Different phylum forms the kingdom. Animals are placed in the animal kingdom whereas plants are placed in the plant kingdom.
Domain: It is placed in the highest position. Kingdom forms a domain.
Taxonomic studies are helpful in agriculture, forestry, industry, and understanding biodiversity. This information is useful in classifying the organisms and storing the information along with the specimens. There are certain procedures and techniques that are established by biologists to preserve the specimen and information. For example,
It is a collection of preserved plant material along with the scientific data associated with it. Specimen kept in a herbarium can be a whole plant, plant parts. They can be in the form of dried samples on paper, or they can be kept in boxes, or any other preservatives. Collection or preservation of fungi is known as Fungarium. Preservation of specimens of wood is known as Xylarium.
Uses of Herbarium
Essential for studying plant taxonomy.
To identify the flora of the area.
It stores the historic record of vegetation with time.
Scientists can study the environmental change and human impacts according to the extinct species with time.
The source of plant DNA is used in plant taxonomy and the study of molecular taxonomy.
It also serves as the repository for viable seeds of rare species.
Collection of living plants for reference. Wide ranges of plants are labeled with botanical names. There are certain special plants that are kept such as cacti, succulents, herb gardens, etc. They also contain special collections such as alpine plants, exotic plants, tropical plants, etc.
Uses of Botanical Gardens
Species diversity can be conserved through botanical gardens.
Living collections of plants maintain genetic diversity.
Helpful for the scientist in the research and the development.
Seed banks are helpful in the safeguard of the species.
They are meant for educational purposes mainly. For example, they are usually set up in colleges, schools, etc. Specimens for preservation are kept in containers or jars along with the preservatives such as formalin. It also includes skeletons of certain animals including human beings. Plants and animals are preserved and kept in dry form. Insects are preserved in insect boxes.
These are parks in which animals are kept in enclosures and displaced to the common public. They are meant for recreation purposes. Animals in zoological parks can also breed. Animals present in zoos are provided with natural conditions in which they live. Children call these parks as zoos. They love to visit these places.
It is a taxonomic aid for the identification of plants and animals based on certain similarities and dissimilarities. It is used for identifying unknown organisms. Separate taxonomic keys are given for each taxonomic category for identification purposes. A Couplet is a pair of contrasting characters used as a tool for identification key to help in the identification of the newly discovered organisms.
Monograph.
A monograph is the writing work of a specialist on a single scholarly subject or an aspect of a subject. It is often written by a single author.
Questions
Very Short Answer Type Questions
A. Name three botanists who contributed to the field of plant taxonomy.
B. Expand ICZN? (Clue: The organization that dictates the correct use of the scientific names of animals)
C. What is a couplet in the taxonomic key?
D. Define a monograph.
E. Define metabolism.
F. The mitotic cell division in amoeba represents growth or reproduction?
G. Name a few botanical gardens in India. Also, name the largest botanical garden in the world.
H. If a habitat contains 20 animal species and 20 plant species, is it “diversity” or “biodiversity”?
I. Identify the correctly written scientific name for mango species- Mangifera indica/Mangifera Indica.
J. What is the lowest category of classification?
K. What are the Taxonomic keys?
L. Who is known as the Father of Taxonomy?
M. What are the 8 levels of taxonomy?
N. What is Taxonomy?
O. What is Reproduction?
P. List out the building blocks of life?
Q. What is Biology?
R. What is Biodiversity?
S. What is DNA?
T. What are Carbohydrates?
U. What is Cellular organization?
Short Answer Type Questions
A. What are the units of classification followed by Botanists while classifying plants?
B. Define the following:
1. Phylum
2. Class
3. Order
4. Genus
C. State the differences between flora, fauna, and vegetation.
D. What do you mean by endemic and exotic species? Give examples for each.
E. The number and kind of organisms are not constant. Explain.
F. Brinjal and potato belong to the same genus but different species. What separates the two species?
G. What is taxon? Give a few examples.
H. A person living in a coma is considered living or dead?
I. What are the different defining properties of a living organism?
J. What is biodiversity?
K. What is ICBN?
L. What are the building blocks of the living system?
M. Write the full form for the following code – ICVN, ICBN, ICZN, ICNB.
N. Define the following terms- Metabolism, Growth and Development.
O. What is binomial nomenclature?
Long Answer Questions
A. What do you mean by living? Explain the defining characteristics of living organisms.
B. With reference to Brassica compestris linn.
1. Give the common name of the plant
2. What do the first two words of the name indicate?
3. Why is the scientific name written in italics?
4. What does “linn.” mean?
C. How will a scientist go about the identification, nomenclature and classification of a plant which he feels is a new species?
D. What is Reproduction?Bottom of Form