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STAR FISH-BLOOD VASCULAR SYSTEM
BLOOD VASCULAR SYSTEM IN STAR FISH A true blood vascular system is absent. In star fish, this system circulates digested food to all body parts. It can be studied under two parts. 1. Perihaemal...
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STAR FISH-NERVOUS SYSTEM AND SENSE ORGANS
NERVOUS SYSTEM AND SENSE ORGANS OF STAR FISH In Star fish the nervous system is primitive and diffuse type. It has no ganglia. It is associated with the epidermis. It has nerve fibres. J. Smith (1937)...
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STAR FISH-REPRODUCTIVE SYSTEM
REPRODUCTIVE SYSTEM-FERTILIZATION - DEVELOPMENT IN STAR FISH Star fish is unisexual. Male and female animals are separate. Sexual dimorphism is not seen. Only during the breeding season they can be...
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ECHINODERMATA LARVAE
Echinodermata larval forms Echinoderms are unisexual animals. Sexual dimorphism is absent. Fertilisation takes place in water. The development may be direct or indirect. If the development is...
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ECHINODERMATA CHAHACTERS- CLASSIFICATION
ECHINODERMATA GENERAL CHARACTERS AND CLASSIFICATION Echinodermata means spiny skinned animals. This name was first proposed by Jacob Kelin (1734) for echi-noids. It was Leuckert (1847) who first...
View ArticleECHINODERMATA WATER VASCULAR SYSTEM
WATER VASCULAR SYSTEM-AMBULACRAL SYSTEM IN DIFFERENT ECHINODERMS Water vascular system (or) Ambulacral system is a peculiar system which is seen in only Echinoderms. This system is modified in...
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BALANOGLOSSUS-EXTERNAL MORPHOLOGY
BALANOGLOSSUS.-HABIT, HABITAT-EXTERNAL CHARACTERS Balanoglossus is a worm like Protochordate organism. It belongs to Phylum: Chordata Subphylum: Hemichordata Order: Enteropneusta. Habit and Habitat: It...
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BALANOGLOSSUS-ANATOMY-BODY WALL
BALANOGLOSSUS -INTERNAL STRUCTURES AND BODY WALL Balanoglossus is a long cylindrical worm like hemichordate animal. It lives in burrows in the sand of intertidal region. It's body wall is smooth. It is...
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BALANOGLOSSUS-DIGESTIVE SYSTEM
DIGESTIVE SYSTEM OF BALANOGLOSSUS Balanoglossus is a worm like chordate animal. It is cylindrical organism and lives in burrows of the sand. This animal shows a long alimentary canal and associated...
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BALANOGLOSSUS- RESPIRATION
RESPIRATION MECHANISM IN BALANOGLOSSUS Balanoglossus lives in burrows in the intertidal sandy areas. Its body is long cylindrical. In its pharynx 'U' shaped gills are present with increase in its age...
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BALANOGLOSSUS-CIRCULATORY SYSTEM
BLOOD VASCULAR SYSTEM IN BALANOGLOSSUS Balanoglossus will show open type of blood vascularsystem. It shows 1. Blood 2. Dorsal sinus 3. Heart 4. Afferent vessel 5. Distributing vessels 6. Collecting...
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BALANOGLOSSUS -REPRODUCTIVE SYSTEM, AND EMBRYO DEVELOPMENT
BALANOGLOSSUS-REPRODUCTION Balanoglossus performs asexual and sexual reproduction Asexual reproduction: Gilchrist described asexual reproduction in Balanoglossus capsensis. In the summer season its...
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HEMICHORDATE CHARACTERS -CLASSIFICATION
HEMICHORDATES -GENERAL CHARACTERS- CLASSIFICATION Balfour classified urochordata, cephalochordata and vertebrata as phylum chordata. But Bateson included Hemichordata in this phylum chordata. These...
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BALANOGLOSSUS-AFFINITIES-PHYLOGENITC RELATIONS
BALANOGLOSSUS-SYSTEMATIC POSITION IN THE ANIMAL KINGDOM Hemichordates show non-chordate and chordate features. These animals show more non-chordate hence Hyman objected its inclusion in the phylum...
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CELL BIOLOOY-INTRODUCTION (brief history of cytology)
Cell biology (Gr., kytos-hollow vessel or cell, logos-to discourse) is a biological science which deals with the study of cells. The cell itself can be regarded as the vital unit of organisms....
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PROKARYOTIC CELL -STRUCTURE
BASIC STRUCTURE OF A PROKARYOTIC CELL The cells which lack true nuclear membrane are called prokaryotic cells. Blue green algae, bacteria are the examples for prokaryotic cells. Prokaryotic cells lack...
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PROKARYOTIC CELL- EUKARYOTIC CELL- DIFFERENCES
Differences between Prokaryotic Cell and Eukaryotic Cell Feature Prokaryotic cell Eukaryotic cell 1. Nuclear envelope absent present 2. DN A ' single, circular and naked more than one and combined...
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AN ANIMAL CELL-STRUCTURE
ANIMAL CELL-STRUCTURE-ORGANELLES Cell is a fundamental, structural and functional unit of living organism. The science which deals with cells and their organelles is called cell-biology. The term cell...
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PLASMA MEMBRANE –CELL MEMBRANE- STRUCTURE -FUNCTIONS
CELL MEMBRANE- PLASMA MEMBRANE STRUCTURE -FUNCTIONS The cytoplasm of the animal cell is bounded by a thin limiting membrane called "Cell membrane". 1) Nageli and Cramer called this membrane as cell...
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MITOCHONDRIA- DEFINITION-STRUCTURE- FUNCTION
MITOCHONDRIA STRUCTURE AND FUNCTIONS DEFINITION OF MITOCHONDRIA: mitochondria are center for cellular respiration. It converts chemical energy into kinetic energy Information About Mitochondria 1) In...
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LYSOSOMES –STRUCTURE-FUNCTIONS
Lysosomes-Structure –Enzymes-Polymorphic Nature-Function-Biogenesis Lysosome : These are first observed in liver cells. They are 1.5 to 2 milii micron in size These are single membrane bounded...
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GOLGI APPARATUS (GOLGI BODY)-STRUCTURE AND FUNCTIONS
GOLGI COMPLEX –STRUCTURE-FUNCTION In the animal and plant cells clusters of fat filled structures are present. They are called Golgi apparatus or complex. In 1898 Camillo Golgi' recognised it in the...
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ENDOPLASMIC RETICULUM-STRUCTURE- TYPES RETICULUM (ROUGH ER- SMOOTH ER) FUNCTIONS
Structure –Types And Functions Of Endoplasmic Reticulum In the cytoplasm of the cell complex membrane bounded system is present. It was called cytoplasmic vacuolar system by "Sacz & De robertis" in...
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RIBOSOMES -STRUCTURE - FUNCTION
Ribosome Structure Types And Functions In 1949 Claude observed ribosomes and called them as microsomes. In 1955 Pallade named them as Ribosomes. Occurance: In both eukaryotic and prokaryotic cells...
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CELL NUCLEUS STRUCTURE-FUNCTION
Structure and Functions of NUCLEAS In Cell In 1832 " Robert Brown" discovered nucleus. It is the essential part of the cell A definite nucleus is absent in prokaryotic cell. Instead of it a DNA...
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