Biospace

What are stem cells? Stem cells are cell develop in animal which is plastic in nature and differentiated into types of cells. All other cells with specialized function are generated under the proper microenvironment in body. One stem cell can produce one stem cell replica and one other type of cell which can be further differentiated and develop into cell line. Stem cell have ability to self- renew, differentiation, plasticity (moldability) History of stem cells In 19th century Theodor Boveri and Valentin Haecker coined the term stem cell. They both are zoologist.(Pic 2) Artur Pappenheim was first discover the theory of blood stem cells in 20th century. He was a German haematologist. (Pic 3). Georges Mathe was perform the bone marrow transplant using stem cell therapy in 1958.he was oncologist and immunologist.(Pic 4) Ernest McCulloch and James Till. define the main properties of stem cells. In 1960s at university of Toronto. They also discover the blood forming stem cel...

Structure of Nucleic acids DNA and RNA form the genetic material of all living organisms. They store the information in biochemical form. What is a gene?   A gene is a sequence of nucleotides in DNA or RNA that encodes the synthesis of a gene product, either RNA or protein.  The genes are expressed by two important process - Transcription of genes from DNA to RNA and then Translation of Genes into Proteins. While DNA makes multiple copies of itself by the process of DNA replication. We will discuss all of them in detail later. Structure of DNA  DNA is a double helical structure. J.D. Watson  and F.H.C. Crick proposed the three-dimensional model of physiological DNA in 1953 on the basis of X-ray diffraction studies of DNA obtained by Franklin and Wilkins. They gave the structure of B- DNA.  The important features of Watson – Crick Model or double helix model of DNA are as follows: 1. The DNA molecule consists of two polynucleotide chains or ...

Now we will study the Cyanobacteria.... CYANOBACTERIA These are blue-green bacterias  photosynthetic , mostly photolysis mediated oxygen evolveing prokaryotes Come among the oldest organisms Thallus ranges from unicellular , colonial to filamentous, multiseriate branched filamentous condition Their distinguishing characters are- Grow on diverse habitats for they have dual-capacity of oxygenic as well as facultatively anoxygenic photosynthesis. possess various morphologically distinctive structures like akinetes and heterocyst. cell wall is made up of peptidoglycan cyanobacterial cytoplasm is covered extensively by flattened vesicular structures called thylakoids or lamellae which are the photosynthetic sites Pigments present are-Chlorophyll-a , Beta-carotene , phycobiliproteins (which include phycocyanin , allophycocyanin , phycoerythrin and allophycocyanin B) . Some are motile and some show gliding movement when not having flagella. Ultrastructure of cyanob...

Biochemistry is the most important part of biology, that is important to understand the living creatures.  Biochemistry  is the study of the chemical substances and vital processes occurring in living organisms.  Biochemists  focus heavily on the role, function, and structure of bio molecules. The study of the chemistry behind biological processes and the synthesis of biologically active molecules are examples of  biochemistry . So i will be discussing biochemistry now,  Lets Start with Water and pH Water The physical and chemical properties of water make it remarkably suitable for its numerous functions in living organisms. The water molecule (H2O) is composed of two atoms of hydrogen and one of oxygen. Each hydrogen atom is linked to the oxygen atom by a single covalent atom. The oxygen atom bears a slight negative charge and each of the two hydrogen atoms bears a slightly positive charge. There is a separation of charge withi...

Now today we will study the Kingdom Monera and Archaebacteria. KINGDOM MONERA General characteristics Most of them are prokaryotic and are among the smallest organisms on earth. The nucleus is not well organised .i.e. the nucleus lacks nuclear membrane, nucleoplasm , chromatin fibres an also nucleoli . Cell Lacks membrane bound organelles like mitochondria , chloroplasts ,etc. 70 S ribosomes are present in the cell where S is the sedimentation co-efficient. Photosynthetic pigments are present in the form of chromatophores. The plasma membrane in folds to to form the mesosome which has the respiratory enzymes . The monerans posses cell wall except the mycoplasma and its composed of Peptidoglycan. They reproduce asexually for they lack sexual reproduction. The genetic material consists of a single DNA molecule and not particular pattern is followed while distribution of Genetic material. A process known as Mitosis Accomplishes this. They ...