• Microbiology

    MICROBIOLOGY

    The word microbiology is derived from the Greek word, MICRO means small, BIOS means life and LOGIA means study. It is the study of microscopic organisms either unicellular, multicellular or acellular. Microbiology include disciplines of Virology, mycology and bacteriology etc. Eukaryotic microorganisms exhibit cell organelles and include fungi, protists and algae. Prokaryotic microorganisms are conventionally classified as lacking organelles and include Eubacteria, Archaebacteria. Microbiologist traditionally relayed on culture, staining and microscopy. However, if only 1 percent of microbes present in the environment are culture able. Microbiologist often relay on extraction or detection of nucleic acid either DNA or RNA. Viruses are not always classified as organisms as they have been…

  • Q & A

    Q & A ON REPRODUCTION IN ORGANISMS

    Q1. What is life span? Ans: Life span is the period from birth to natural death of an organism. Q2. Define clone. Ans: The individuals that are morphologically and genetically similar to the parent are called clone. Q3. Mention the different means/ methods of asexual reproduction with example. Ans:  Cell division – Protista, Monera Binary fission – Amoeba, Paramecium Budding – Yeast Zoospores (microscopic motile endogenous spores) – aquatic fungi, chlamydomonas Conidia (microscopic immotile exogenous spores)- pencillium External buds – hydra Internal buds like gemmules – sponges (spongilla) Q4.Unicellular organisms are immortal. Justify. Ans: Single celled organisms like amoeba & bacteria reproduce by cell division and there is no natural…

  • Biochemistry,  Q & A

    Q & A ON WATER AND MINERAL SALT

    Q1.  What is the approximate percentage (in mass) of water in the human body? Is this percentage expected to be larger in the adult or in the old individual?  Ans: Approximately 65% of the human individual mass is water. The brain, for example, has around 90% of water in mass, the muscles, 85%, and the bones have between 25% and 40% of water. Younger adult individuals have proportionally more water in mass than older individuals. Q2.  What are the main biological functions of water? Ans: Water is the fundamental solvent for chemical reactions of living beings; it is the main means of substance transportation in the cell and between cells…

  • Biochemistry,  Cell biology,  Genetics

    WHAT IS DNA?

    Deoxyribonucleic acid (DNA) is a molecule that carries most of the genetic instructions used in the development, functioning, and reproduction of all known living organisms and many viruses. DNA is a nucleic acid; alongside proteins and carbohydrates, nucleic acids compose the three major macromolecules essential for all known forms of life. DNA  stores instructions for making other large molecules, called proteins. These instructions are stored inside each of your cells, distributed among 46 long structures called chromosomes. These chromosomes are made up of thousands of shorter segments of DNA, called genes. Each gene stores the directions for making protein fragments, whole proteins, or multiple specific proteins. DNA is well-suited to…

  • Q & A

    Q & A OF ANATOMY OF FLOWERING PLANTS

    Q1) Name the associated structure of companion cell. Ans: Sieve tube cell Q2) Name an enucleated plant cell. Ans: Sieve tube cell Q3) Name the conductory elements of xylem. Ans: Tracheary elements- Tracheids and Vessels (tracheae)  Q4) What is periderm? Ans: Phellogen, Phellum and Phelloderm are collectively called as Periderm Q5) What is annual ring? Ans: Springwood and autumn wood that appear as alternate concentric rings constitute an annual ring.  Q6) Name the meristem which is responsible for growth in diameter of the cortex. Ans: Cork Cambium Q7) What is intrafascicular cambium? Ans: Cells of cambium present between primary xylem and primary phloem. Q8) What is interfascicular cambium? Ans: The…

  • Botony

    ANATOMY OF DICOTYLEDONOUS AND MONOCOTYLEDONOUS PLANTS

    For a better understanding of tissue organisation of roots, stems and leaves, it is convenient to study the transverse sections of the mature zones of these organs. Dicotyledonous Root Look at Figure, it shows the transverse section of the sunflower root. The internal tissue organisation is as follows: The outermost layer is epiblema. Many of the cells of epiblema protrude in the form of unicellular root hairs. The cortex consists of several layers of thin-walled parenchyma cells with intercellular spaces. The innermost layer of the cortex is called endodermis. It comprises a single layer of barrel-shaped cells without any intercellular spaces. The tangential, as well as radial walls of the…

  • Botony

    THE TISSUE SYSTEM- ANATOMY OF FLOWERING PLANTS

    We were discussing types of tissues based on the types of cells present. Let us now consider how tissues vary depending on their location in the plant body. Their structure and function would also be dependent on location. On the basis of their structure and location, there are three types of tissue systems. These are the epidermal tissue system, the ground or fundamental tissue system and the vascular or conducting tissue system. Epidermal Tissue System The epidermal tissue system forms the outer-most covering of the whole plant body and comprises epidermal cells, stomata and the epidermal appendages – the trichomes and hairs. The epidermis is the outermost layer of the…

  • Botony

    THE TISSUES- ANATOMY OF FLOWERING PLANT

    A tissue is a group of cells having a common origin and usually performing a common function. A plant is made up of different kinds of tissues. Tissues are classified into two main groups, namely, meristematic and permanent tissues based on whether the cells being formed are capable of dividing or not. Meristematic Tissues Growth in plants is largely restricted to specialised regions of active cell division called meristems (Gk. meristos: divided). Plants have different kinds of meristems. The meristems which occur at the tips of roots and shoots and produce primary tissues are called apical meristems (Figure). Apical meristem: Shoot Apical meristem: Root Root apical meristem occupies the tip…