Biology: Branches, Concepts, Notes & NCERT Solutions

Collegedunia Team logo

Collegedunia Team Content Curator

Content Curator

Biology is the study of life and life processes. Biology is the basis for the scientific study of living organisms and their respective characteristics. Life science, medicine, conservation, genetics, microbiologyCell biology and various other fields are distributaries of the subject of Biology. Modern technology has led its way to Interdisciplinary research by integrating various disciplines such as Chemistry, physics and medicine to gear up the development in biology and its allied fields. In Class 12 syllabus, Biology subject is divided into Botany (study of plants) and Zoology (Study of animals).

Also Read: Comparison Articles in Biology

Branches of Biology

Branches of Biology


Aspects of Biology

The different aspects of biology and their subtopics are discussed below.

Taxonomic Hierarchy of Organisms

There are millions of living organisms in the world and without any classification, it is impossible to identify each of them separately. Thus, all the organisms are classified in a taxonomic hierarchy in the order of Kingdom → Phylum → Class → Class → Order → Family → GenusSpecies.

Below are some concepts that explains in detail about the Plant kingdom, morphology of plants and their functions.

Below are some concepts that explains in detail about the Animal kingdom, lifecycle of animals & insects, their functions and anatomy.


Ecology and Environment

All the living organisms in this world constantly interact with one another for the basic need of survival. The inter-relationship between these organisms determines the balance between environment and organisms. The food chain, biomass, energy pyramid, etc maintain the proportion and balance to lead a sustainable life.


Cell- Basic Unit of Life

Cell is the basic unit of life. Cells are broadly classified into Plant cells and animal cells. The only difference between the two is that animal cells don’t have a cell wall. Cells contains cell organelles which have different functions to promote the growth of the cell. Some of the cell organelles are the nucleus, mitochondria, vacuoles, cytoplasm, endoplasmic reticulum, cell wall, cell membrane, etc. The DNA or the genetic information is present inside the nucleus. 


Unicellular and Multicellular Organisms 

All organisms can be classified into unicellular or multicellular. Unicellular organisms are single celled microscopic organisms. Some of the examples of unicellular organisms are amoeba, paramoecium, euglena, etc. Apart from these, all other organisms are multicellular where a group of cell with common function makes up a tissue, tissues together form organ and organs together form organ system. 


Microbiology 

It is the study of microorganisms such as bacteria, virus, fungi, algae, etc. It is also necessary to study the characteristics and function of each of these organisms. Depending of the study of the subject, microbiology is classified into different fields such as bacteriology (study of bacteria), virology (study of viruses), mycology (study of fungus), etc.


Physiology, Health and Hygiene

It is very important to take good care of health and hygiene. The study of various organs of the human body and its functions forms a large portion of the subject. It also deals with the diseases that occurs in the body which may be either communicable or non-communicable diseases. The sources, preventive measures and treatment for these dieases also come under the purview of the subject.

Below are some articles that explains in detail about different physiological functions of human body and their respective organs.

Below are some articles that explains in detail about different hormones secreted in the human body and their respective functions.

Below are some articles that explains in detail about different types of vitamins and their deficiency diseases in the human body.


Genetics and Evolution

The passing on of characteristics from one generation to another is called heredity. Any minute changes in this gene transfer might cause a unique characteristic which forms the basis for evolution. Evolution has been the case since life appeared on earth. Evolution helps in adapting to the changing environment. 


CBSE CLASS XII Related Questions

  • 1.
    If a natural population of 60 individuals is in Hardy-Weinberg equilibrium for a gene with two alleles B and b, with the gene frequency of allele B of 0.7, the genotype frequency of Bb will be:

      • ( 0.21 )
      • ( 0.42 )
      • ( 0.49 )
      • ( 0.56 )

    • 2.
      Name any two VDs which might occur in a human female. State any two complications in a female if it is left untreated.


        • 3.

          Flowering plants with hermaphrodite flowers have developed many reproductive strategies to ensure cross-pollination. Study the given outbreeding devices adopted by certain flowering plants and answer the questions that follow.

          Note : All plants belong to the same species. No pollen tube growth/inhibition of pollen germination on stigma. Pollen germination on stigma.

          • [(a)] Name and define the outbreeding device described in the above table.
          • [(b)] Explain what would have been the disadvantage to the plant in the absence of the given strategy.


            • 4.

              Given below is a heterogeneous RNA formed during Eukaryotic transcription:

              heterogeneous RNA

              How many introns and exons respectively are present in the hnRNA?

                • 7, 7
                • 8, 7
                • 8, 8
                • 7, 8

              • 5.
                Enlist three advantages of genetically modified plants.


                  • 6.
                    Student to attempt either option (A) or (B):
                    (A)
                    (i) Explain why the milk produced by the mother during the initial days of lactation is considered to be very essential for the newborn infant.
                    (ii) What is the term used for the milk produced during the initial days of lactation?
                    OR
                    (B) Many children in the metro cities are suffering from a very common exaggerated response of the immune system to certain weak antigens in air.
                    (i) What is the term used for the above mentioned disease?
                    (ii) Name the main type of antibody produced by the immune system in response to this disease.
                    (iii) Which two main inflammation-causing chemicals are produced by the mast cells in such an immune response?

                      CBSE CLASS XII Previous Year Papers

                      Comments


                      No Comments To Show