Zoology is the branch of biology in which we study animals


CYTOPLASM The cytoplasm of a cell has two distinct parts: ---------------------------- ---------------------------- The Cytomembrane system: It consists of well-defined structures, such as endoplasmic reticulum, Golgi apparatus. vacuoles, and vesicles. The fluid cytosol: It suspends the structures of the cytomembrane system. Italso contains various dissolved

Kingdoms of Life – Classification & Evolution

Kingdoms of Life 1. Kingdom classification system In 1969. Robert II. Whittaker described a system of classification. This classification forms five kingdoms. The basis of classification of Whittaker is: (i)        Cellular organization (ii)       NtIode of nutrition. Fig (a) Five kingdom system classification, (b) Recent

Molecular Approaches to Animal Systematics

Molecular Approaches to Animal Systematics Molecular approach includes study of molecules like protein, DNA, RNA of different species. Molecular techniques provide important information in recent years. These information are used for taxonomic studies. The animals have sequence of nitrogenous bases in DNA. These sequence


Nomenclature The assignment of a distinctive name to each species is called nomenclature. Common names have two problems: (a)    First, common names vary from country to country. Even they vary from region to region within a country. Some species have hundreds of different common

Taxonomic Hierarchy

A Taxonomic Hierarchy There are two basis of taxonomic hierarchy: (a)        Taxonomic hierarchy based on morphology Karl von Linne (Carolus Linnaeus) gave the modern classification system. It is still used today. He believed that different species could be grouped into same categories. This grouping


CLASSIFICATION OF ORGANISM The study of kinds and diversity of organisms and the evolutionary relationships among them is called systematics or taxonomy. The study of systematics gives the order and relationships among the organisms. This relationship arises from e evolutionary processes. These studies also

Movement of membrane across plasma membrane

      greater than it inside. Filtration Hydrostatic       pressure     forces     small molecules            across            selectively permeable membranes from areas of higher    pressure     to   areas    of    lower pressure. A frog’s blood         pressure forces           water          and dissolved wastes into the kidney        tubules      during urine formation. Active


Molecules can cross membranes in a-number of ways. They may use their own energy. Or they rely on an outside energy source. There are following types of cell movements. SIMPLE DIFFUSION Th movement of molecules from the area of higher concentration to the ar


The plasma membrane surrounds the cell. Chemically plasma membrane is composed of: Protein: 60 to 80% Phospholipids: 20 to 40 % Cholesterol in small amount Carbohydrates in small amount Fig: Fluid mosaic model of plasma membrane STRUCTURE OF CELL MEMBRANE S. onathan Singer and