TISSUES
abidaThe group of similar cells which performs same functions is called tissue. There are four types of tissues: epithelial tissues, connective tissues, muscles tissues and nerve tissues. Epithelial tissues The…
Nomenclature
sidraThe assignment of a distinctive name to each species is called nomenclature. Problems with common names Common names have two problems: I. First, common names vary from country to country.…
NUCLEUS
Nucleus contains most of the genes that control the cell. It is the most conspicuous organelle in the eukaryotic cell. Its average diameter is about 5. It performs two major…
Nucleic Acid – Discovery , Significance & Types
rubabNucleic acid is polymer of nucleotides. Discovery A German Chemist. Friedrich Miescher. discovered Nucleic in 1869. Ile discovered DNA only four years after the publication of Menders work. Miescher extracted…
ANIMAL SYSTEMATICS (CLASSIFICATION)
saadiaANIMAL SYSTEMATICS (CLASSIFICATION) Following groups used in animal classification: 1. Monophyletic Groups: The groups showing similarities due to single ancestors are called monophyletic groups. The classification based on monophyletic groups…
VACOULES AND VESICLES
Vacuoles and vesicles are membrane-enclosed sacs within the cell. But vacuoles are larger than vesicles. Vacuoles have various functions. They form food by phagocytosis. Many freshwater protists have contractile vacuoles…
ESSENTIAL ELEMENT
sanaThe elements which are needed by the plants for normal and healthy life are called essential elements. Only 16 elements, are essentigl elements. -Mere are two ty pes olessential elements:…
CENTRIOLES AND MICROTUBULE ORGANIZING CENTERS
Microtubule-organizing centers The specialized non membranous regions of cytoplasm near the nucleus are the microtubule-organizing centers. These centers contain dense material. This material gives rise to a large number of…
THE CYTOSKELETON
The cytoskeleton is a network of fibers suspended through the cytoplasm. There are three fibers in the cytoskeleton. These are microtubuies, microfilaments and intermediate filaments. Functions of Cytoskeleton - The…
ACTIVE ABSORPTION OF MINERALS
The concentration of mineral solutes is much higher in the absorbing cells than outside in most cases. This increased concentration of minerals in the cells is called solute accumulation. Salt…