INTRODUCTION

Animals, for the most part, ingest their food as large, complex molecules that must be broken down into smaller molecules (monomers) that can then be distributed throughout the body of every cell. This vital function is accpomplished by a series of specialized organs that comprise the digestive system.

INTRODUCTION

The integumentary system (From Latin integumentum, from integere ‘to cover’; from in- + tegere ‘to cover’ is the organ system that protects the body from damage, comprising the skin and its appendages (including hair, scales, feathers, and nails). The integumentary system has a variety of functions; it may serve to waterproof, cushion, and protect the deeper tissues, excrete wastes, and regulate temperature, and is the attachment site for sensory receptors to detect pain, sensation, pressure, and temperature. In humans the integumentary system also provides vitamin D synthesis.

The skin is the largest organ in the body: 12-15% of body weight, with a surface area of 1-2 meters. Skin is continuous with, but structurally distinct from mucous membranes that line the mouth, anus, urethra, and vagina. Two distinct layers occur in the skin: the dermis and epidermis. The basic cell type of the epidermis is the keratinocyte, which contain keratin, a fibrous protein. Basal cells are the innermost layer of the epidermis. Melanocytes produce the pigment melanin, and are also in the inner layer of the epidermis. The dermis is a connective tissue layer under the epidermis, and contains nerve endings, sensory receptors, capillaries, and elastic fibers.

INTRODUCTION

The ability to reproduce is one of the unifying characteristics of all living things. Sexual reproduction produces offspring that are genetically different from their parents.Asexual reproduction produces offspring genetically identical to their parent.

ASEXUAL REPRODUCTION

• Asexual reproduction allows an organism to rapidly produce many offspring without the time and resources committed to courtship, finding a mate, and mating.
• Fission, budding, fragmentation, and the formation of rhizomes and stolons are some of the mechanisms that allow organisms to reproduce asexually.
• The hydra produces buds;
• starfish can regenerate an entire body from a fragment of the original body.

INTRODUCTION

Cellular respiration involves the breakdown of organic molecules to produce ATP. A sufficient supply of oxygen is required for the aerobic respiratory machinery of Kreb’s Cycle and the Electron Transport System to efficiently convert stored organic energy into energy trapped in ATP. Carbon dioxide is also generated by cellular metabolismand must be removed from the cell. There must be an exchange of gases: carbon dioxide leaving the cell, oxygen entering. Animals have organ systems involved in facilitating this exchange as well as the transport of gases to and from exchange areas.

RESPIRATION IN SINGLE CELL ANIMALS

Single-celled organisms exchange gases directly across their cell membrane. However, the slow diffusion rate of oxygen relative to carbon dioxide limits the size of singlecelled organisms. Simple animals that lack specialized exchange surfaces have flattened, tubular, or thin shaped body plans, which are the most efficient for gas exchange. However, these simple animals are rather small in size.

RESPIRATION IN MULTICULTURAL ANIMALS

Large animals cannot maintain gas exchange by diffusion across their outer surface. They developed a variety of respiratory surfaces that all increase the surface area for exchange, thus allowing for larger bodies. A respiratory surface is covered with thin, moist epithelial cells that allow oxygen and carbon dioxide to exchange. Those gases can only cross cellmembranes when they are dissolved in water or an aqueous solution, thus respiratory surfaces must be moist.

METHODS OF RESPIRATION OF VARIOUS ORGANISMS

(a) Sponges and jellyfish lack specialized organs for gas exchange, so they take gases directly from the surrounding water.

(b) Flatworms and annelids use their outer surfaces as gas exchange surfaces. Earthworms have a series of thin-walled blood vessels known as capillaries. Gas exchange occurs at capillaries located throughout the body as well as those in the respiratory surface

(c) Amphibians use their skin as a respiratory surface. Frogs eliminate carbon dioxide 2.5 times as fast through their skin as they do through their lungs. Eels (a fish) obtain 60% of their oxygen through their skin. Humans exchange only 1% of their carbon dioxide through their skin. Constraints of water loss dictate that terrestrial animals must develop more efficient lungs.

(d) Arthropods, annelids, and fish use gills: Gills greatly increase the surface area for gas exchange. They occur in a variety of animal groups including arthropods (including some terrestrial crustaceans), annelids, fish, and amphibians.Gills typically are convoluted outgrowths containing blood vessels covered by a thin epithelial layer. Typically gills are organized into a series of plates and may be internal (as in crabs and fish) or external to the body (as in some amphibians).Gills are very efficient at removing oxygen fromwater: there is only 1/20 the amount of oxygen present in water as in the same volume of air.Water flows over gills in one direction while blood flows in  the opposite direction through gill capillaries. This countercurrent flow maximizes oxygen transfer. Terrestrial vertebrates utilize internal lungs:

INTRODUCTION

Living things must be capable of transporting nutrients, wastes and gases to and from cells. Single-celled organisms use their cell surface as a point of exchange with the outside environment. Multicellular organisms have developed transport and circulatory systems to deliver oxygen and food to cells and remove carbon dioxide and metabolic wastes.

CIRCULATORY SYSTEMS IN SINGLE CELLED ORGANISMS

Single-celled organisms use their cell surface as a point of exchange with the outside environment. Sponges are the simplest animals, yet even they have a transport system. Seawater is the medium of transport and is propelled in and out of the sponge by ciliary action. Simple animals, such as the hydra and planaria lack specialized organs such as hearts and blood vessels, instead using their skin as an exchange point for materials. This, however, limits the size an animal can attain. To become larger, they need specialized organs and organ systems.

CIRCULATORY SYSTEMS IN MULTICELLULAR ORGANISMS

Multicellular animals do not have most of their cells in contact with the external environment and so have developed circulatory systems to transport nutrients, oxygen, carbon dioxide andmetabolicwastes.Components of the circulatory system include

i. Blood: a connective tissue of liquid plasma and cells
ii. Heart: a muscular pump to move the blood
iii. Blood vessels: arteries, capillaries and veins that deliver blood to all tissues

TYPES OF CIRCULATORY SYSTEMS

(a) The open circulatory system The open circulatory system, examples molluscs and arthropods. Open circulatory systems (evolved in insects, mollusks and other invertebrates) pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells. Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood. The resulting blood flow is sluggish.

INTRODUCTION

The nervous system coordinates rapid and precise responses to stimuli using action potentials. The endocrine system maintains homeostasis and long-term control using chemical signals. The endocrine system works in parallel with the nervous system to control growth and maturation along with homeostasis.

HORMONES

The endocrine system is a collection of glands that secrete chemical messages we call hormones. These signals are passed through the blood to arrive at a target organ, which has cells possessing the appropriate receptor. Exocrine glands (not part of the endocrine system) secrete products that are passed outside the body. Sweat glands, salivary glands, and digestive glands are examples of exocrine glands. Hormones are grouped into three classes based on their structure:

1. Steroids
2. Peptides
3. Amines

1. STEROIDS

Steroids are lipids derived from cholesterol. Testosterone is the male sex hormone. Estradiol, similar in structure to testosterone, is responsible for many female sex characteristics. Steroid hormones are secreted by the gonads, adrenal cortex, and placenta.

2. PEPTIDES AND

3. AMINES

Peptides are short chains of amino acids; most hormones are peptides. They are secreted by the pituitary, parathyroid, heart, stomach, liver, and kidneys. Amines are derived from the amino acid tyrosine and are secreted from the thyroid and the adrenal medulla. Solubility of the various hormone classes varies.

Synthesis, Storage, and Secretion

• Steroid hormones are derived from cholesterol by a biochemical reaction series. Defects along this series often lead to hormonal imbalances with serious consequences. Once synthesized, steroid hormones pass into the bloodstream; they are not stored by cells, and the rate of synthesis controls them.

• Peptide hormones are synthesized as precursor molecules and processed by the endoplasmic reticulum and Golgi where they are stored in secretory granules. When needed, the granules are dumped into the  bloodstream. Different hormones can often be made from the same precursor molecule by cleaving it with a different enzyme.

• Amine hormones (notably epinephrine) are stored as granules in the cytoplasm until needed.

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EVOLUTION OF ENDOCRINE SYSTEMS

Most animals with well-developed nervous and circulatory systems have an endocrine system. Most of the similarities among the endocrine systems of crustaceans, arthropods, and vertebrates are examples of convergent evolution. The vertebrate endocrine system consists of glands (pituitary, thyroid, adrenal), and diffuse cell groups secreted in epithelial tissues. More than fifty different hormones are secreted. Endocrine glands arise during development for all three embryologic tissue layers (endoderm, mesoderm, ectoderm). The type of endocrine product is determined by which tissue layer a gland originated in. Glands of ectodermal and endodermal origin produce peptide and amine hormones; mesodermal-origin glands secrete hormones based on lipids.

i. Endocrine Systems and Feedback Cycles

The endocrine system uses cycles and negative feedback to regulate physiological functions. Negative feedback regulates the secretion of almost every hormone. Cycles of secretion maintain physiological and homeostatic control. These cycles can range from hours to months in duration.

ii. Mechanisms of Hormone Action

The endocrine system acts by releasing hormones that in turn trigger actions in specific target cells. Receptors on target cell membranes bind only to one type of hormone. More than fifty human hormones have been identified; all act by binding to receptor molecules. The binding hormone changes the shape of the receptor causing the response to the hormone. There are two mechanisms of hormone action on all target cells.

iii. Nonsteroid Hormones

No steroid hormones (water soluble) do not enter the cell but bind to plasma membrane receptors, generating a chemical signal (second messenger) inside the target cell. Five different second messenger chemicals, including cyclic AMP have been identified. Second messengers activate other intracellular chemicals to produce the target cell response.

iv. Steroid Hormones

The second mechanism involves steroid hormones, which pass through the plasma membrane and act in a two step process. Steroid hormones bind, once inside the cell, to the nuclear membrane receptors, producing an activated hormone-receptor complex. The activated hormonereceptor complex binds toDNAand activates specific genes, increasing production of proteins.

THE LYMPHATIC SYSTEM

• The lymphatic system is composed of lymph vessels, lymph nodes, and organs. The functions of this system include the absorbtion of excess fluid and its return to the blood stream, absorption of fat (in the villi of the small intestine) and the immune system function.

• Lymph vessels are closely associated with the circulatory system vessels. Larger lymph vessels are similar to veins. Lymph capillaries are scatted throughout the body. Contraction of skeletal muscle causes movement of the lymph fluid through valves.

• Lymph organs include the bone marrow, lymph nodes, spleen, and thymus.
• Bone marrow contains tissue that produces lymphocytes. B-lymphocytes (B-cells) mature in the bone marrow.
• T-lymphocytes (T-cells) mature in the thymus gland.
• Other blood cells such as monocytes and leukocytes are produced in the bone marrow.
• Lymph nodes are areas of concentrated lymphocytes and macrophages along the lymphatic veins.
• The spleen is similar to the lymph node except that it is larger and filled with blood.
• The spleen serves as a reservoir for blood, and filters or purifies the blood and lymph fluid that flows through it.

• If the spleen is damaged or removed, the individual is more susceptible to infections.
• The thymus secretes a hormone, thymosin, that causes pre-T-cells to mature (in the thymus) into T-cells.

IMMUNITY

INTRODUCTION

The single-celled protozoan ancestors of animals had their weight supported by water and were able to move by cilia or other simple organelles. The evolution of large and more complex organisms (animals) necessitated the development of support and locomotion systems. Animals use their muscular and skeletal systems for support,  locomotion, and maintaining their shape.

SKELETAL SYSTEMS OF VARIOUS ANIMALS

(i) Movement is a major characteristic of animals. This movement is a result of contraction of muscles. The skeleton helps transmit that movement. Skeletons are either a fluid-filled body cavity, exoskeletons, or internal skeletons.

(ii) Hydrostatic skeletons consist of fluid-filled closed chambers. Internal pressures generated by muscle contractions cause movement as well as maintain the shape of the animals, such as the sea anemone and worms. The sea anemone has one set of longitudinal muscles in the outer layer of the body, and a layer of circular muscles in the inner layer of the body. The anemone can elongate or contract its body by contracting one or the other set of muscles.

(iii) Exoskeletons are characteristic of the Phylum Arthropoda. Exoskeletons are hard segments that cover the muscles and visceral organs. Muscles for movement attach to the inner surface of the exoskeleton Exoskeletons restrict the growth of the animal, thus it must shed its exoskeleton (or molt) to form a new one that has room for growth. The bulk and weight of the exoskeleton and associated mechanical problems limits the size a animals can attain.

Note : Spiders use a combination of an exoskeleton for protection and fluid pressure for movement. Vertebrates have developed an internal mineralized (in most cases) endoskeleton composed of bone and/or cartilage. Muscles are on the outside of the endoskeleton.

Cartilage and bone are types of connective tissue.

• Sharks, and rays have skeletons composed entirely of cartilage; other vertebrates have an embryonic cartilage skeleton progressively replaced by bone as they mature and develop.
• Some areas of the human body, however, retain cartilage in the adult: in joints and flexible structures such as the ribs, trachea, nose and ears.

THE SKELETON AND MUSCLES

• The skeleton and muscles function together as the musculoskeletal system. This system (often treated as two separate systems, the muscular, and skeletal) plays an important homeostatic role: allowing the animal to move to more favorable external conditions.

• Certain cells in the bones produce immune cells as well as important cellular components of the blood.
• Bone also helps regulate blood calcium levels, serving as a calcium sink. Rapid muscular contraction is important in generating internal heat, another homeostatic function.

TYPES OF SKELETONS

• The axial skeleton consists of the skull, vertebral column, and rib cage.
• The appendicular skeleton contains the bones of the appendages (limbs, wings, or flippers/fins), and the pectoral and pelvic girdles.
• The human skull, or cranium, has a number of individual bones tightly fitted together at immovable joints.
• At birth many of these joints are not completely structured together as bone, leading to a number of “soft spots” or fontanels, which do not completely join until the age of 14-18 months.
• The vertebral column has 33 individual vertebrae separated from each other by a cartilage disk. These disks allow a certain flexibility to the spinal column, although the disks deteriorate with age, producing back pain. The sternum is connected to all the ribs except the lower pair. Cartilage allows for the flexibility of the rib cage during breathing.
• The arms and legs are part of the appendicular skeleton.
• The upper bones of the limbs are single: humerus (arm) and femur (leg).
• Below a joint (elbow or knee), both limbs have a pair of bones (radius and ulna in the arms; tibia and fibula in legs) that connect to another joint (wrist or ankle).
• The carpals makeup the wrist joint; the tarsals are in the ankle joint.

Each hand or foot ends in 5 digits (fingers or toes) composed of metacarpals (hands) or metatarsals (feet).

Limbs are connected to the rest of the skeleton by collections of bones known as girdles. The pectoral girdle consists of the clavicle (collar bone) and scapula (shoulder blade).

BONE

Although bones vary greatly in size and shape, they have certain structural similarities. Bones have cells embedded in a mineralized (calcium) matrix and collagen fibers. Compact bone forms the shafts of long bones; it also occurs on the outer side of the bone. Spongy bone forms the inner layer.

Compact bone has a series of Haversian canals around which concentric layers of bone cells (osteocytes) and minerals occur. New bone is formed by the osteocytes. The Haversian canals form a network of blood vessels and nerves that nourish and monitor the osteocytes.

Spongy bone occurs at the ends of long bones and is less dense than compact bone. The spongy bone of the femur, humerus, and sternum contains red marrow, in which stem cells reproduce and form the cellular components of the blood and immune system. Yellow marrow, at the center of these bones, is used to store fats. The outer layer of the bones is known as the periosteum.

The inner layer of the periosteumforms new bone or modifies existing bone to meet new conditions. It is rich in nerve endings and blood and lymphatic vessels.When fractures occur, the pain is carried to the brain by nerves running through the periosteum.

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GROWTH OF BONE

Endochondral ossification is the process of converting the cartilage in embryonic skeletons into bone. Cartilage is deposited early in development into shapes resembling the bones-to-be. Cells inside this cartilage grow and begin depositingminerals.

• The spongy bone forms, and osteoblasts attach and lay down themineral portions of spongy bone. Osteoclasts remove material from the center of the bone, forming the central cavity of the long bones. The perichondrium, a connective tissue, forms around the cartilage and begins forming compact bone while the above changes are occurring. Blood vessels form and grow into the perichondrium, transporting stem cells into the interior.
• Two bands of cartilage remain as the bone develops, one at each end of the bone.
• During childhood, this cartilage allows for growth and changes in the shape of bones. Eventually the elongation of the bones stops and the cartilage is all converted into bone.

• Bones continue to change as adults, to adapt to the stresses generated by physical activity. Exercise can increase the diameter and strength of bone; inactivity can decrease them. Age is a factor: osteoporosis is a disease that primarily affects older, postmenopausal women. Increasing calcium intake, reducing protein intake, exercise and low doses of estrogen are effective treatments for osteoporosis.

TYPES OF JOINTS

INTRODUCTION

Multicellular animals must monitor and maintain a constant internal environment as well asmonitor and respond to an external environment. In many animals, these two functions are coordinated by two integrated and coordinated organ systems: the nervous systemand the endocrine system. Three basic functions performed by nervous systems are:-

1. Receive sensory input from internal and external environments
2. Integrate the input
3. Respond to stimuli

SENSORY INPUT

Receptors are parts of the nervous system that sense changes in the internal or external environments. Sensory input can be in many forms, including pressure, taste, sound, light, blood pH, or hormone levels, that are converted to a signal and sent to the brain or spinal cord.

INTEGRATION AND OUTPUT

In the sensory centers of the brain or in the spinal cord, the barrage of input is integrated and a response is generated. The response, a motor output, is a signal transmitted to organs than can convert the signal into some form of action, such as movement, changes in heart rate, release of hormones, etc.

ENDOCRINE SYSTEMS

Some animals have a second control system, the endocrine system. The nervous system coordinates rapid responses to external stimuli. The endocrine systemcontrols slower, longer lasting responses to internal stimuli. Activity of both systems is integrated.

DIVISIONS OF THE NERVOUS SYSTEM

• The nervous system monitors and controls almost every organ system through a series of positive and negative feedback loops.
• The Central Nervous System (CNS) includes the brain and spinal cord.
• The Peripheral Nervous System (PNS) connects the CNS to other parts of the body, and is composed of nerves (bundles of neurons).
• Not all animals have highly specialized nervous systems.
• Those with simple systems tend to be either small and very mobile or large and immobile.
• Large, mobile animals have highly developed nervous systems: the evolution of nervous systems must have been an important adaptation in the evolution of body size and mobility.

NERVOUS SYSTEM IN VARIOUS ORGANISMS

Coelenterates, cnidarians, and echinoderms have their neurons organized into a nerve net. These creatures have radial symmetry and lack a head. Although lacking a brain or either nervous system (CNS or PNS) nerve nets are capable of some complex behavior. Bilaterally symmetrical animals have a body plan that includes a defined head and a tail region. Development of bilateral symmetry is associated with cephalization, the development of a head with the accumulation of sensory organs at the front end of the organism. Flatworms have neurons associated into clusters known as ganglia, which in turn form a small brain. Vertebrates have a spinal cord in addition to a more developed brain. Chordates have a dorsal rather than ventral nervous system. Several evolutionary trends occur in chordates: spinal cord, continuation of cephalization in the form of larger and more complex brains, and development of a more elaborate nervous system.

VERTEBRATE NERVOUS SYSTEM

The vertebrate nervous system is divided into a number of parts. The central nervous system includes the brain and spinal cord. The peripheral nervous system consists of all body nerves. Motor neuron pathways are of two types: somatic (skeletal) and autonomic (smoothmuscle, cardiac muscle, and glands).The autonomic system is subdivided into the sympathetic and parasympathetic systems.

WHAT IS CELL?

All living organisms on earth are divided in pieces called cells. Cells are small compart-ments that hold all of the biological equipments necessary to keep organisms. Cells carry out all the basic functions of life: growth, metabolism and r e pr o- duct ion . There are someorganisms like amoeba consists of a single cell. This single cell increasein size and when it attains a certain size, it divides into two separates individuals. In case of multi cellular organisms, the cell also divides into two parts, but the two parts remaining joined this process is repeated crore of times so that body mass is built up. In this process some cells become specialized to perform specific functions but other retains their capacity for cell division throughout life.

WHO GAVE THE CELL THEORY?

The term cell was coined by Robert Hooke in 1665. In 1838 matthias schleiden, German botanist proposed the idea that all plants consists of cells. In 1839, The Eodor Schwann a German zoologist asserted that all plant and animals are made up of cells. This finding forms the basis of cell theory.

COMPONENTS OF CELL?

In the living organisms there are two types of cellular organizations. If we look at very simple organisms like bacteria and blue-green algae, We will discover cells that have no defined nucleus, these are prokaryotes cells. The cells which have definite nucleus are known as eukaryote. But the things which both have in common is that there are compartments surrounded by some type of membranes. These are called cell membranes.

Cell membranes : It is like a plastic bag with some tiny holes that bag holds all of the cell pieces and fluids inside the cell and keeps foreign particles outside the cell. The holes are there to let some things move in and out of the cell. Compounds called proteins and phospholipids make up most of the cell membrance.the phospholipids make the basic bag. The proteins are found around the holes and help move molecules in and out of the cell. Substances like Co2 and O2  can move across the cell membranes by a process called diffusion. Diffusion is a process of movements of substance from a region of high concentration to a region where its concentration is low. Water also obeys the law of diffusion. The movement of water molecules is called osmosis.

Cytoplasm : It is the fluid that fills a cell. Scientists used to call the fluid proto plasm.cytoplasm contain many specialized cell called organ cells. Each of these organ cells performs a specific function for the cell. Cell organells : Organells are living part of the cell have definite shape, structure and functions. To keep their function different from each other these organelles use membranes bound little structure with in them selves. Some of the important organells are :

(a) Endoplasmic reticulum : It is a network of tulsular membranes connected at one end to the nucleus and on the other to the plasma membranes. Endoplasmic reticular (ER) are two types:-rough endoplasmic reticular (RER) and Smooth endoplasmic reticulum (SER).

Functions of ER:

• It forms the supporting skeleton frame work of the cell.
• It provides a pathway for distribution of nuclear material.
• It provides surface for various enzymatic reactions.

Tissue is a cellular organizational level intermediate between cells and a complete organism. Hence a tissue is an ensemble of cells not necessarily identical, but fromthe same origin, that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues. The study of tissue is known histology.

ANIMAL TISSUE

The structure of animal tissue is directly related to its function. Tissue is groups of cells with a basic structure and function. There are four types of tissues.

TYPE OF ANIMAL TISSUE

• Epithelial tissue
• Connective tissue
• Muscular tissue
• Nervous tissue.

EPITHETICAL TISSUE:

It is a tissue that is made up of tightly packed cells. Without much materials with in these cells. The reasons for the tightly packed cells are to act as a barrier against mechanical injury, invading micro- rganisms and fluid loss. We can define epithetical tissue by considering two points in mind one is the number of cells layers and two the shape of the cells.

(i) On the basis of cell layers

(a) When an epitheliumhas a single layer of cells it is called a simple epithelium.

(b) Where as a multiple tier of cells are known as stratified epithelium.

(ii) On the basis of simple shape of cells:

• Cuboidal : its occurrence is in kidney tubules, salivery glands, inner lining of the cheek. Its main function is to give mechanical strength.
• Columnar : its occurrence is in sweat gland, tear gland, salivary gland its main function is to gives mechanical strength concerned with secretions.
• Squamous : when it forms a living as that of blood vessels, it is called endothelium. Its main function is to protect the underlying parts from injury, entry of germs, etc.
• Connective tissue : its main function is to bind and support other tissues. They have sparse populations of cells scattered through an extra cellular matrix. This extra cellular matrix is a web of fibers that is  woven in a homogeneous ground substance they can be liquid, solid, or jelly like. There are a few types of connective tissue.

CONNECTIVE TISSUE:

A. Areolar tissue : It fills spaces inside organs found around muscles, blood vessels and nerves. Its main function is to joins skin to muscles, support internal organs, help in the repair of tissues.Where as tendon’s main function is to connect muscles to bones and ligament is connects bones to each other.

B. Adipose tissue : its occurrence is below skin, between internal organs and in the yellow bone Marrow. Its main function is to storage of fat and to conserve heat.

C. Skeletal tissue : Bone & Courtilage cartilage occurrences is in nose pic, epigotis and in intervertebral disc of mammals. Its main function is to provide support and flexibility to body part. Where as bone protects internal delicate organs provides attachments for muscles, bone marrow makes blood cells.

D. Fluid tissue : Blood & Lymph blood transport O2 nutrients, hormones to tissues and organs. Where as leucocytes fight diseases and platelets help in cloting of blood. Lymph transport nutrients into the heart and it also forms the defense system of the body.

MUSCULAR TISSUE:

It is specialized for an ability to contract muscle cells. These are elongated and referred to as muscle fibers. When a stimulates is received at one end of a muscle cell, a wave of excitation is conducted through the entire cell so that all parts contract in harmony. There were three types of muscle cells: skeletal, cardiac, and smooth muscles.

Muscular tissue:

• skeletal
• cardiac
• Smooth muscle tissue.

A. Skeletal muscle : It attached primarily to bones. Its main function is to provide the force for locomotion and all other voluntary movements of the body.

B. Cardiac muscle : It occurs only in the heart. The contraction and relaxation of the heart muscles help to pump the blood and distribute it to the various parts of the body.

C. Smooth muscles : It can be found in stomach, intestines, and blood vessels these muscles cause slow and prolonged contractions which are involuntary.

D. Nervous tissue : This tissue is specialized with a capability to conduct electrical impulses and convey information from one area of the body to another. Most of the nervous tissue (98%) is located in the central nervous system. The brain and spinal cord. There are two types of nervous tissue neurons and neuroglia.

NERVOUS TISSUE:

• Neurons
• Neuroglia

Neurons: it actually transmit the impulses, receptor nerve ending of neurons react to various kind of stimuli and can transmit waves of excitation from the farthest point in the body to the central nervous system. You will read all the details in Chapter Four.

Important facts regarding animal tissue:-

• Muscles contain special protein called contractile protein. Which contract and relax to cause movement.

• Fat storing adipose tissue is found below the skin and between internal organs.
• Two bones are connected to each other by a tissue called ligament. This tissue is very elastic.
• The skin, the living of the mouth, the living blood vessels, kidney tubules are allmade up of epithelial tissue.
• Voluntary muscles and cardiac muscles are richly supplied with water where as involuntarymuscles are poorly supplied with blood.
• Muscles tissue is composed of differtiated cells containing contractile protein.

PLANT TISSUE:

INTRODUCTION

Plants are composed of three major organ groupsroots, stems and leaves. These are comprised of tissue working together for a common goal (function). In turn tissues are made up of number of cells which are made of elements and atoms on the most fundamental level. Plant tissue can be divided differently into two types:

1. Permanent tissues
2. Meristematic tissue.

1. Permanent tissue : plant tissue are characterized and classified according to their structure and function. These tissues can be simple, consisting of a single cell type. They can also be complex, consisting of more than one cell type. These tissues are incapable of cell division. Therefore these tissues are called permanent tissue.
Types of Permanent tissue

• Simple
• Complex

A. Simple permanent tissue : These are of three types.

• Parenchyma
• Collenchyma
• Sclerenchyma

(i) Parenchyma :

• It occurs in all soft parts of plants like cortea of roots and is meant for storage of food and provides turgidity to softer parts of plants.
• Certain parenchymatous tissues contain chloroplast and synthesize food.
• In aquatic plant parenchymatous cells are stellate and have air cavities between them to store air, such tissue is called aerenchyma.
• The outermost protective layer of plants is made up of specially modified parenchyma. These cells are without intercellular spaces.

(ii) Collenchyma :

• It occurs in hypodermis of stemand petiole and around veins.
• Generally it is absent in roots, leaves and monocot stems
• This tissue provides mechnical support and in some cases it may possess chloroplasts to perform photo synthesis.

(iii) Sclerenchyma :

• It is a tissue of dead and thick walled cells having no intercellular spaces.
• It is the chief mechanical tissue in plants and is able to bear push, pull, strain and shearing forces. They are of two types.
• Selerenchyma fibres
• Sclereids or stone cells.

Selerenchyma fibres : they usually occur as patches in pericylcle of dicotstem and within xylem and phloem. These are source of natural fibres like jute, coir, hemp, Levin etc.

Sclereids or stone cells : they occur in hard covering of seeds shell of nuts, endocarp of stung fruits, bark and pith of certain plants. They provide stiffness to part where they occur.

B. Complex permanent tissue : complex tissues are made up of more than one type of cells. All these cells coordinate to perform a common function. Xylemand phloemare examples of such complex tissue.

i. Xylem
ii. Phloem

(i) Xylem :

Scheduled Tribes and Other Traditional Forest Dwellers

(Recognition of Forest Rights) Act, enacted in 2006, is a tool to provide occupational and habitat ional rights to the people, thus, incentivising conservation and sustainable use of biological resources by providing access to livelihood enhancing resources to people.

National Biotechnology Development Strategy, 2007

IV. Livestock genetic diversity

India, endowed with varied forms of animal genetic resources, is traditionally considered as an important rearing centre for domesticated animals. India has vast resources of livestock (485 million) and poultry (489 million), which play a vital role in rural livelihood security. In terms of population, India ranks first in buffaloes, second in cattle and goats, third in sheep, fourth in ducks, fifth in chicken and sixth in camels in the world. The genetic resources of farm animals in India are represented by broad spectrum of native breeds of cattle buffaloes, goats, sheep, swine, equines, camel and poultry. There are around 140 listed breeds of livestock and poultry in India, with 30 breeds of cattle, 10 of buffalo, 42 of sheep, 20 of goat, 3 of pig, 6 of horse an pony, 8 of camel and 18 of poultry. Besides, there are breeds of yak, mithun, ducks, quails and several nondescript populations.

Conservation is the protection, preservation, management, or restoration of wildlife and natural resources such as forests and water. Through the conservation of biodiversity the survival of many species and habitats which are threatened due to human activities can be ensured. Other reasons for conserving biodiversity include securing valuable Natural Resources for future generations and protecting the well being of eco-system functions.

The United Nations Commission on Sustainable Development (CSD) was established in December 1992 by General Assembly Resolution A/RES/47/191 as a functional commission of the UNEconomic and Social Council, implementing a recommendation in Chapter 38 of Agenda 21, the landmark global agreement reached at the June 1992 United Nations Conference on Environment & Development/Earth Summit held in Rio de Janeiro. 

1. Overview

India is faced with the challenge of sustaining its rapid economic growth while dealing with the glob¬al threat of climate change. This threat emanates from accumulated greenhouse gas emissions in the atmosphere, anthropogenically generated through long-term and intensive industrial growth and high consumption lifestyles in developed countries. While engaged with the international community to collec¬tively and cooperatively deal with this threat, India needs a national strategy to firstly, adapt to climate change and secondly, to further enhance the ecolog¬ical sustainability of India's development path.

Climate change may alter the distribution and quality of India's natural resources and adverse¬ly affect the livelihood of its people. With an econo¬my closely tied to its natural resource base and cli¬mate-sensitive sectors such as agriculture, water and forestry, India may face a major threat because of the projected changes in climate.
India's development path is based on its unique resource endowments, the overriding priori¬ty of economic and social development and poverty eradication, and its adherence to its civilizational legacy that places a high value on the environment and the maintenance of ecological balance.

In charting out a developmental pathway which is ecologically sustainable, India has a wider spectrum of choices precisely because it is at an earlystage of development. Our vision is to create a pros¬perous, but not wasteful society, an economy that is self-sustaining in terms of its ability to unleash the creative energies of our people and is mindful of our responsibilities to both present and future genera¬tions.
Recognizing that climate change is a global challenge, India will engage actively in multilateral negotiations in the UN Framework Convention on Climate Change, in a positive, constructive and for¬ward-looking manner. Our objective will be to establish an effective, cooperative and equitable global approach based on the principle of common but differentiated responsibilites and respective capabilities, enshrined in the United Nations Framework Convention on Climate Change (UNFCCC). Such an approach must be based on a global vision inspired by Mahatma Gandhi's wise dic¬tum—The earth has enough resources to meet peo¬ple's needs, but will never have enough to satisfy people's greed. Thus we must not only promote sus¬tainable production processes, but equally, sustain¬able lifestyles across the globe.

affirm their responsibility for accumulated green¬house gas emissions and fulfill their commitments under the UNFCCC, to transfer new and additional financial resources and climate friendly technologies to support both adaptation and mitigation in devel¬oping countries.

Biosequestration is the capture and storage of the atmospheric greenhouse gas carbon dioxide by biological processes.
This may be by increased photosynthesis (through practices such as reforestation / preventing deforestation and genetic engineering); by enhanced soil carbon trapping in agriculture; or by the use of algal bio sequestration (see algae bioreactor) to absorb the carbon dioxide emissions from coal, oil or gas-fired electricity generation.

Soil is the most important layer of the earth’s crust. It is a valuable resource.

Soil is the mixture of rock debris and organic materials which develop on the earth’s surface. The major factors affecting the formation of soil are relief, parent material, climate, vegetation and other life-forms and time. Besides these, human activities also influence it to a large extent. Components of the soil are mineral particles, humus, water and air. The actual amount of each of these depend upon the type of soil. Some soils are deficient in one or more of these, while there are some others that have varied combinations.

A river drains the water collected from a specific area, which is called its ‘catchment area'

The flow of water through well-defined channels is known as ‘drainage’ and the network of such channels is called a ‘drainage system’. The drainage pattern of an area is the outcome of the geological time period, nature and structure of rocks, topography, slope, amount of water flowing and the periodically of the flow.

Climate refers to the sum total of weather conditions and variations over a large area for a long period of time (more than thirty years). Weather refers to the state of the atmosphere over an area at any point of time. The elements of weather and climate are the same, i.e. temperature, atmospheric pressure, wind, humidity and precipitation. Youmay have observed that the weather conditions fluctuate very often even within a day. But there is some common pattern over a few weeks or months, i.e. days are cool or hot,windy or calm, cloudy or bright, and wet or dry. On the basis of the generalized monthly atmospheric conditions, the year is divided into seasons such as winter, summer or rainy seasons. During the summer season the desert area of Rajasthan witnesses 50º temperature whereas Pahalgamsector of Jammu and Kashmir has 20ºC temperature. During winter nights Dras sector of Jammu and Kashmirwitnesses– 45ºC temperature where as Thiruvananth puram has 20ºC. Rainfall also varies in terms of quantity and distribution in the regions of Himalaya rainfall is in the from of snowy balls where as in the rest of part of India it is a general rain. Again annual rainfall varies from 400ºC in the Meghalya to 10ºc in Ladakh and West Rajasthan. In the coastal area the variation of rainfall is less. Whereas in the inner part of country the seasonal variation is more. Accordingly the Indians show their unity in diversity in terms of food, clothing, housing and culture.