Online Questions on Chapter = 6 ( TISSUE) 9th class

These are Online Practice Questions on Chapter =  6 ( TISSUE) for preparation of CBSE BOARD Examination, NTSE etc.

VERY SHORT ANSWER TYPE QUESTIONS (1 Mark)

1. The tissue derived directly from the meristem of embryo is called as................ .

2. A group of cells with similar structure organized to do a common function is called as................ .

3. Which plant tissue remains in active metabolic state always ?

4. Sieve tubes and companion cells are found in................tissue. (Xylem/ phloem/collenchyma)

5. Long, narrow, dead cells having a thick deposition of lignin in the cell wall are called................cells. (Parenchyma/cambium/sclerenchyma)

6. Which tissue is responsible for transport of water in plants ?

7. The special property of muscle fibres to contract forcefully and return to relaxed state is called..................(excitability/contractibility/flexibility)

8. A branch of science dealing with the study of bones is called................ .
(Ornithology/physiology/osteology)

9. The fluid matrix of blood is called................ . (plasma/lymph/serum)

10. Spindle-shaped, non-striated, involuntary muscle fibres present in hollow internal organs like urinary bladder are called................ . (smooth muscle fibres/striated muscle fibres/cardiac muscle fibres)

11. The brain and the spinal cord are made up of................ . (nephrons/erythrocytes/neurons)

12. The small, branched processes of a nerve cell are called................ .
(dendrites/axons/neurons).

SHORT ANSWER TYPE QUESTIONS (2 Marks)

1. Define tissue.

2. What do you mean by division of labour ?

3. Name the different elements of xylem and phloem.

4. In hydrophytes xylem is less developed. Why ?

5. Write the composition of mammalian blood.

6. What is the function of nervous tissue ?

7. State the main features of muscular tissue.

LONG ANSWER TYPE QUESTIONS (5 Marks)

1. What is tissue ? Explain meristematic plant tissue.

2. Mention the role of parenchyma, collenchymas and sclerenchyma.

3. Give summarized classification of animal-tissue.

4. Describe the structure of neuron with labelled diagram.

Online Notes on Chapter = 6 ( TISSUE) Part 3

This is Biology Online Notes on Chapter = 6 ( TISSUE) Part 3 of 9th class of NCERT Book for preparation of examinations like CBSE Board, Biology Olympiad, NTSE, CSIR NET etc.

ANIMAL TISSUE:

EPITHELIAL TISSUE:

• Always grows on some other types of tissue.

• Cells of epithelium are set very close to each other and the tissue     rests on a non-cellular basement membrane.

• Consists of single layer of cells.

• Blood vessels are absent and non-nervous in nature.

• It covers all the organs and lines the cavities of hollow organs            like stomach.

• It is primarily protective in function.

Types of Epithelium:

Epithelium tissues are classified as :

(a) Squamous epithelium : Also called pavement epithelium.

• Cells arranged end to end like tiles on a floor.

• Cells are polygonal in surface view.

• It forms the delicate lining of cavities (mouth, oesophagus, nose,

  pericardium, alveoli etc.) blood vessels and covering of the tongue

  and skin.

• Epithelial cells are arranged in many layers (stratum) to prevent       wear and tear in skin. This pattern is stratified squalors                     epithelium.

(b) Cubical epithelium :

• They are cube like cells that fit closely, cells look like squares in

section, but free surface appears hexagonal.

• It is found in kidney tubules, thyroid vesicles & in glands   (salivary glands, sweat glands).

• It forms germinal epithelium of gonads (testes & ovaries).

• It involves in absorption, excretion & secretion. It also provides

   mechanical support.

(c) Columnar epithelium :

• Columnar means ‘pillar-like’ epithelium. It forms lining of                stomach.

• Small intestine & colon, forming mucous membranes.

• Border of micro villi is present at the free surface end of each cell

   which increases absorption efficiency in small intestine.

(d) Ciliated epithelium :

• Cells may be cubical or columnar.

• On its free surface are present protoplasmic outgrowths called           cilia.

• It helps in the movement of ova in the fallopian tube.

CONNECTIVE TISSUE:

• The cells of the connective tissue are widely spaced and                  embedded in an intercellular matrix.

• The mature of matrix decides the function of tissue.

• White and yellow fibres are present in the matrix.

• Their basic function is to provide support to different organs &

   keeping them in place.

(a) Fluid or vascular tissue :

Blood and lymph:

• Blood is a connective tissue, fluid matrix of blood is plasma             having wandering or floating cells, called corpuscles, blood             helps  in the transportation of various materials such as nutritive       substances, gases, excretory products, hormones etc. 

• Plasma Form 55% part of blood. Constitution : 90-91% : water,       7% : protein (Albumin, fibrinogen, globulin), 0.9% : inorganic         salt etc. Corpuscles

• Forms 45% part of blood. RBCs

• They are also called as erthyrocytes, containing red coloured             respiratory pigment called haemoglobin that helps in                         transportation of oxygen.

WBCs (Leucocytes : They are also called as ‘Soldiers of the              body’.)

• They are irregular, amoeboid, phagocyte cells that protect our body by engulfing bacterial & other foreign particles. They are of five types :

Monocytes, Lymphocytes, Basophiles, Neutrophiles, Eosinophils.

Blood platelets or thrombocytes

• They are spindle shaped cells which are involved in clotting of blood.

(b) Skeletal Tissue:

Bone:

• Matrix of bone is very hard because of salts such as calcium            phosphate, CaCO3 (60-70%) etc. and a protein ossein.

• Bone cells (osteoblasts) are embedded in this hard matrix.

• Matrix is deposited in the form of concentric layers of lamellae        formed round a central canal, the done cells occupy small spaces      between the concentric layers of matrix.

• The long bones are usually hollow containing cavity called as          marrow cavity. It is full of bone marrow.

Cartilage:

• This tissue is elastic, less harder as compared to bones.

• Elasticity is due to presence of chondrin (protein). Cells are              called  as chondroblast, which are widely spaced and matrix is        reinforced by fibres.

• It occurs at joint of bones, in the nose, ear, trachea & larynx.

• It provides flexibility and great tensile strength.

(c) Connective tissue:

It is the most abundant type of connective tissue. It is further divided into following types :

(i) Yellow fibrous connective tissue

• They are very elastic due to the presence of a network of yellow fibres in its matrix called as ligament which attaches bone to bone.

(ii) White fibrous connective tissue

• They are very little matrix containing abundant white fibres forming layers.

• Bundles of this tissue are called as tendons, which attaches muscles to the bones.

(d) Aerolar tissue :

• It is the most distributed connective tissue in the body.
• This tissue fills spaces inside organs and is found between the skin & muscles, around blood vessels, nerves and in the bone marrow.

(e) Adipose tissue :

• These are oval and round cells, filled with fat globules.
• The cells are called as adipocytes.
• It is found in subcutaneous layer below the skin, around the heart, brain and below the eyeballs. It acts as an insulator and prevents loss of heat from the body.

MUSCULAR TISSUE:

• Movements are brought about in our body with the help of muscular tissues.
• They are long fibre-like cells called muscle fibres.
• They are capable of contraction or relaxation.

Types of Muscular Tissue:

(a) Striated muscles:

• They are also called as voluntary muscles because these are under the control of one’s will.

• Muscle fibres or cells are multinucleated and unbranched.

• Each fibre is enclosed by thin membrane which is called as sarcolemma Cytoplasm is called as sarcoplasm.

• These muscles get tired and need rest.

(b) Cardiac muscle fibres:

• They are only involuntary muscles.

• Only found in the walls of heart.

• Their structure is in between the striated and non-striated muscles.

• They are uninucleated and branched. Branches are united by intercalated disc.

• In these muscles rhythmic contraction and relaxation occurs throughout the life.

(c) Non-striated muscles:

• They are involuntary muscles also called as smooth muscles.

• These muscle fibres are uninucleated and spindle shaped.

• They are not enclosed by membrane but many fibres are joined together in bundles.

• Such muscles are found in the walls of stomach, intestine, urinary bladder, bronchi, iris of eye etc.

• Peristaltic movements in alimentary canal are brought about by smooth muscles.

NERVOUS TISSUE:

• They are highly specialized tissue due to which the animals are able to perceive and respond to the stimuli.

• Their functional unit is called as nerve cell or neuron.

• Cell body is cyton covered by plasma membrane.

• Short hair like extensions rising from cyton are Dendron which are further subdivided into dendrites.

• Axon is long, tail like cylindrical process with fine branches at the end. Axon is covered by a sheath.

• Axon of one neuron is very closely placed to the dendrons of another neuron to carry impulses from one to another neuron in the form of electrochemical waves. This close proximity is called as synapse.

Online Notes on Chapter = 6 ( TISSUE) Part 2

This is Biology Online Notes on Chapter = 6 ( TISSUE) Part 2 of 9th class of NCERT Book for preparation of examinations like CBSE Board, Biology Olympiad, NTSE, CSIR NET etc.

(b) Supporting Tissues : These are supportive in function and are of three types :

(i) Parenchyma : It is the fundamental tissue.

• Tissue first time evolved in bryophyte.

• Thin walled cells, oval or spherical in structure.

• Cell wall mainly composed of cellulose & pectin.

• Large central vacuole for food & water storage.

• Primary function is food storage.

• Some parenchyma involved in excretory substance storage are

   so called as idioblast, storing such as resin, tannin, gums & oils.

• In typical parenchyma chlorophyll is absent.

• Chloroplast containing parenchyma tissue are chlorenchyma

which perform photosynthesis e.g., mesophyll of leaves.

• In hydrophytic plants aerenchyma (a type of parenchyma

   containing air spaces) provides buoyancy.

• Parenchyma provides turgidity to cells.

(ii) Collenchyma : It is the living mechanical tissue.

• Elongated cells with thick corners.

• Localized cellulose & pectin thickening.

• Provides flexibility to plant parts & easy bending of various

   parts of plant.

• Present only in herbaceous dicot stem.

• Present at thin margin of leaves.

• Few chloroplasts may be present.

• Gives mechanical strength & elasticity to the growing stems.

(iii) Sclerenchyma : (Scleras – hard) Strengthening tissue.

• Composed of extremely thick walled cells with little or no

   protoplasm.

• Cells are dead & possess very thick lignified walls.

• Lignin is water-proof material.

• Intercellular spaces are absent.

Cells of sclerenchyma are of two types :

Sclereids :

• These are also called grit cells or stone cells.

• These are small cells, where lumen is so small due to higher             thickening of cell wall, as present in drup fruit (mango, coconut,      walnut) in legume seeds (Macrosclereid).

Fibers :

• They are very long, narrow, thick, lignified cells. Lumen is large       as compared to sclereids. Generally 1-3 mm long.

• In the thick walls of both the fibres and sclereids are present thin

   areas called as pits.

Sclrenchyma Fibres:

• These are used in the manufacture of ropes, mats & certain textile

   fibres.

• Jute and coir are obtained from the thick bundle of fibres.

(B) Complex Permanent Tissues:

• It consists of more than one type of cells which work together as a

   unit.

• It helps in transportation of organic materials, water & minerals.

• It is also known as conducting or vascular tissue.

• Xylem & phloem together form vascular bundles.

Xylem : Also known as wood and is a vascular and mechanical tissue.Thick walled cells are found in the form of tubular passages.

Xylem consists of four types of cells called as elements :

(i) Tracheids :

• They are elongated angular dead cells (primitive elements) mainly

    involved in conduction of water and minerals in gymnosperms.

(ii) Vessles : They are advance element (generally found in                     angiosperms).

• Vessels are cylindrical tube like structures placed one above the        other end to end which form a continuous channel for efficient        conduction of water.

(iii) Xylem parenchyma :

• They are small & thick walled parenchymatous cells subjected for

storage of starch (food).

(iv) Xylem sclerenchyma :

• Thy are non-living fibres with thick walls and narrow cavities           provide mechanical support.

• Except xylem parenchyma all other xylem elements are dead.

• The annual rings present in the trunk of a tree are xylem rings.

• By counting the number of annual rings, we can determine the         age of a tree.

Phloem : They also consist of both parenchymatous and schlerenc-

    -hymatous cells.

Phloem consists of four types of element :

(i) Sieve tubes :

• Sieve tubes are slender tube like structures made up of elongated,

   thin walled cells placed end to end.

• The end walls of sieve tube cells are perforated by numerous              pores, called as sieve plates.

• Nucleus of sieve cell degenerates at maturity. However, cytoplasm

   persists, because of protoplasmic continuation of sieve tube with

   companion cell through plasmodesmata.

• Sieve cells possess slime protein or protein which is concerned         with growth and repair of sieve cells.

(ii) Companion cells :

• Companion cells have dense cytoplasm and prominent nuclei.

   * Sieve cells & companion cells are so called sister cells because     they originate from single mother cell.

(iii) Phloem fibre :

• They give mechanical support to sieve tubes.

(iv) Phloem parenchyma :

• They store food and help in radial conduction of food.

(v) Leptome :

• Main part of phloem involved in conduction of food, which is           sieve tube.

• In xylem, only unidirectional movement is possible while in             phloem bidirectional movement can occur.

• In phloem, except phloem sclerenchyma all elements are living.

Online Notes on Chapter = 6 ( TISSUE) Part 1

This is Biology Online Notes on Chapter = 6 ( TISSUE) Part 1 of 9th class of NCERT Book for preparation of examinations like CBSE Board, Biology Olympiad, NTSE, CSIR NET etc.

CHAPTER AT A GLANCE:

PLANT TISSUE – Meristematic & Permanent

Meristematic Tissue:

These are simple living tissues having thin walled compactly arranged immature cells which are capable of division and formation of new cells.

Main features of Meristematic tissues are :

• Thin primary cell wall (cellulosic).

• Intercellular spaces are absent (compact tissue).

• Generally vacuols are absent, dense cytoplasm & prominent             nuclei are present.

• Large numbers of cell organelles are present.

• Active metabolic state, stored food is absent.

• Actively dividing cells are present in growing regions of plants         e.g., root & shoot tips.

Classification on the Basis of Origin:

(A) Primary (Promeristem):

• Derived directly from the meristems of embryo.

• They consist of cells derived from primary meristem.

• They add to primary growth of plants

(B) Secondary:

• Formed by permanent tissues.

• These are having cells derived from primary permanent tissue.

• They usually add to the diameter of plants.

Permanent tissue differentiation Secondary Meristem:

Classification on the Basis of Location:

(A) Apical Meristem

• It is present at the growing tips of stems and roots.

• Cell division in this tissue leads to the elongation of stem & root,     thus it is involved in primary growth of the plant.

(B) Intercalary Meristem

• It is present behind the apex.

• It is the part of apical meristem which is left behind during growth

    period.

• These are present at the base of leaf & internode region.

• These lead to the increase in the length of leaf (Primary) e.g., in        grass stem, bamboo stem, mint stem etc.

(C) Lateral Meristem

• It is also called as secondary meristem.

• It occurs along the sides of longitudinal axis of the plant.

• It gives rise to the vascular tissues.

• Causes growth in girth of stem & root.

• They are responsible for secondary growth.

PERMANENT TISSUE:

• The permanent tissues are composed of those cells which have          lost their capability to divide.

• They have definite shape, size and thickness. The permanent              tissue may be dead or living.

• The division & differentiation of the cells of meristematic tissues      give rise x

• The cells of permanent tissue loose the capacity to divide and            attain a permanent shape, size and function.

Depending upon the Structure and Composition, the Permanent tissues are classified into two types :

(A) Simple Permanent Tissues

• These are made up of same type of cells which are similar                  structurally and functionally.

• They include two types of tissue :

(a) Protective Tissues : These tissues are primarily protective in

function. 

They consist of :

(i) Epidermis

• Epidermis forms one cell thick outermost layer of various body

  organs of plants such as leaves, flowers, stems and roots.

• Epidermis is covered outside by cuticle. Cuticle is a waterproof

  layer of waxy substance called as cutin which is secreted by the      epidermal cells.

• Cuticle is very thick in xerophytes.

• Cells of epidermis of leaves are not continuous at some places

   due to the presence of small pores called as stomata.

• Each stomata is guarded by a pair of bean-shaped cells called

   as guard cells. These are the only epidermal cells which possess

   chloroplasts, the rest being colourless.

Functions of Epidermis:

• The main function of epidermis is to protect the plant from

   desiccation and infection.

• Cuticle of epidermis cuts the rate of transpiration and

   evaporation of water and prevents wilting.

• Stomata in epidermis allow gaseous exchange to occur during

   photosynthesis respiration.

• Stomata also helps in transpiration.

(ii) Cork or Phellem:

• In older roots and stems, tissues at the periphery become cork 

   cells or phellem cells.

• Cork is made up to dead cells with thick walls and do not have

   any intercellular spaces.

• The cell walls in cork deposit waxy substance called as suberin.

• The cells of cork become impermeable to water and gases due

   to the deposition of suberin.

• The cork cells are without any protoplasm but are filled with

   resins or tannins.

Functions of Cork :

• Cork is protective in function. Cork cells prevent desiccation,

   infection and mechanical injury.

• Imperviousness, lightness, toughness, compressibility and

   elasticity make the cork commercially valuable.

• Cork is used for insulation, as shock absorber in linoleum.

• Cork is used in the making of a variety of sport goods such as

   cricket balls, table tennis, shuttle cocks, wooden paddles etc.

Questions on Chapter = 5 ( THE FUNDAMENTAL UNIT OF LIFE)

These are Online Practice Questions on Chapter =  5 ( THE FUNDAMENTAL UNIT OF LIFE) 

VERY SHORT ANSWER TYPE QUESTIONS (1 Mark):

1. Name the largest cell of living world ?

2. Amoeba is a.............organism.

3. Who gave the fluid mosaic model of plasma membrane ?

4. Movement of solvent into the cell is called as................. .

5. Which cell organelle is called as the ‘Head quarter of cell’ ?

6. Which cell organelle is called as ‘Power house of cell’ ?

7. Which cell organelle contains enzymes for ATP production ?

8. In mitochondria, which portion contains specific proteins ?

9. Which cell organelle is called as ‘Digestive bag’ ?

10. Which organelle controls osomostic pressure in a cell ?

11. Plastids having coloured pigments are called as............... .

SHORT ANSWER TYPE QUESTIONS (2 Marks):

1. What is the composition of protoplasm ?

2. Define cell ?

3. What is the difference between diffusion and osmosis ?

4. Why plasma membrane is called as selectively permeable                 membrane ?

5. Define Cristae ?

6. State any two function of Golgi body ?

7. Name various type of plastids present in a plant cell ?

8. State the main function of lisosome ?

LONG ANSWER TYPE QUESTIONS (5 Marks):

1. Who gave the cell theory ? What does it state ? Which organism      is an exception of cell theory ?

2. Draw a neat and labelled diagram of nucleus. State its main              function.

3. Describe the types of endoplasmic reticulum and draw necessary      figure ? Give its main functions also?

4. Draw a neat and labelled diagram of mitochondria.

5. Differentiate between plant and animal cell with suitable figures.

Online Notes on Chapter = 5 ( THE FUNDAMENTAL UNIT OF LIFE) Part 4

This is Online Notes on Chapter =  5 ( THE FUNDAMENTAL UNIT OF LIFE)  Part 4 for preparation of CBSE BOARD Examination, NTSE etc.

Mitochondria:

It is a rod shaped structure found in cytoplasm of all eukaryotic cells except mammalian RBC’s.

• These are also absent in prokaryotes.

• It was first seen by Kolliker in insect cells.

• Maximum mitochondria are found in metabolically active cells.

• It is also called as ‘Power House of the Cell’ or the ‘Storage Battery’.

• It is double membranous structure where outer membrane has specific proteins while inner membrane is folded inside to form chambers called "Cristae".

Functions of Mitochondria :

(a) Its main function is to produce and store the energy in the form of ATP.

(b) It is the site of Kreb cycle of respiration

Ribosomes:

Ribosomes are the sites of protein synthesis.

All structural and functional proteins (enzymes) coded by the nuclear DNA are synthesized upon cytoplasmic ribosomes. The DNA codes are transcripted into messenger RNA (mRNA) molecules in the chromosomes of the nucleus.

Functions of Ribosomes :

(a) Ribosomes are the main site of protein synthesis. Synthesized

proteins is transported by endoplasmic reticulum.

Plastid:

• It is double membranous discoidal structure, found only in plant cells.

• Besides being discoidal of rhombic in plant cells, they occur in variable shapes like in algae. They can be ‘U’-shaped, spiral, coiled, ribbonshaped etc.

Depending upon the type of pigment present in them, they are of following three types :

(i) Leucoplast – White, found in underground parts

(ii) Chloroplast – Red, brown

(iii) Chloroplast – Green in colour, found in aerial parts of plants

These are found only in plant cell. It helps in the process of photosynthesis so it is called the ‘Kitchen of Plants’.

Chloroplast have following two parts :

(i) Grana : It constitutes the lamellar system. These are found layered on top of each other. These stacks are called Grana. Each granum of the chloroplast is formed by superimposed closed compartments called Thylakoids.

Function : They are the sites of light reaction of photosynthesis as they contain photosynthetic pigment chlorophyll. In each thylakoid,

Quantasomes are present which are called as Photosynthetic units.

(ii) Stroma : It is a granular transparent substance also called as

matrix. Grana are embedded in it. Besides Grana they also contain lipid droplets, starch grains, ribosomes etc.

Function : This is the site of dark reaction of photosynthesis. Also helps in protein synthesis due to presence of ribosomes.

Vacuoles:

• These are membrane bounded regions in the cytoplasm containing water and other substances.

• They are bounded by a single membrane called Tonoplast.

• In animal cells vacuoles are smaller in size and numerous while in plant cells a single large vacuole is found which occupies about 90% of the volume of cell.

Functions :

It helps in maintaining osmotic pressure in a cell & stores toxic metabolic products of plant cell.

Lysosome:

• They are tiny sac-like granules containing enzymes of intracellular digestion.

• They are bounded by a single membrane.

• They occur in animal cells and a few plant cells.

• They do not have a definite shape or size.

Functions :

(a) Their main function is phagy = digestion.

(b) They are kind of waste disposal system.

(c) They help in digesting foreign materials & cells.

Suicidal Bag : During disturbances in cellular metabolism i.e., in case of cell damage, lysosomes burst and their enzymes are released into the cytoplasm and they digest their own cell. So they are also called ‘Suicidal Bag’.

Online Notes on Chapter = 5 ( THE FUNDAMENTAL UNIT OF LIFE) Part 3

This is Online Notes on Chapter =  5 ( THE FUNDAMENTAL UNIT OF LIFE)  Part 3 for preparation of CBSE BOARD Examination, NTSE etc.

Cell Wall:

• It is the outermost covering of the plant cells.

• It is absent in animal cells.

• Cell wall is rigid, strong, thick, porous and non-living structure. It is made up of cellulose and hemicelluloses. Cell walls of two adjacent cells are joined by a layer called middle lamellae.

Functions of Cell Wall :

(a) It provides definite shape to the cell.

(b) It provides strength to the cell.

(c) It is permeable and allows entry of molecules of different sizes.

(d) It has the characteristics of repair and regeneration.

Nucleus:

•Nucleus is the most important cell organelle which directs and controls all its cellular activities.

• It is called as ‘Headquarter of the cell’.

• It was discovered by Robert Brown in 1831.

• In Eukaryotes, a well-defined nucleus is present while in Prokaryotes, a well-defined nucleus is absent.

• Prokaryotes contain a primitive nucleus.

• It has double layered covering called as nuclear membrane.

• Nuclear membrane has pores which regulate the movement of materials in & out of the cell.

• Besides nuclear membrane, nucleus also contains nucleolus and

chromatin material and the substance filled inside the nucleus is nucleolus.

• Chromosomes or chromatin material consists of DNA which stores and transmits hereditary information for the cell to function, grow and reproduce.

Functions of Nucleus :

(a) It controls all the metabolic activities of the cell and regulates the cell cycle.

(b) It helps in transmission of hereditary characters from parents to

off springs.

Cytoplasm:

• Cytoplasm was discovered by Kolliker in 1862.

• It is the site of both biosynthetic and catabolic pathways.

• It can be divided into two parts :

(i) Cytosol : Aqueous soluble part contains various fibrous proteins

forming cytoskeleton.

(ii) Cell organelles : Living part of the cells having definite shape,

structure and function bounded by plasma membrane.

Endoplasmic Reticulum:

• It is the network of membranes present in the cytoplasm.

• It was discovered by Porter, Claude and Fullam.

• These are present in all cells except prokaryotes and mammalian

erythrocytes.

Functions of ER :

(a) It is the only organelle which can move within a cell so it serves

as a channel for the transport of materials between various regions of cytoplasm and between cytoplasm and nucleus.

(b) It also functions as a cytoplasmic framework to provide space for some of the biochemical activities. It forms endoskeleton of cell.

(c) It helps in synthesis of fats, steroids, cholesterol etc.

(d) SER plays a crucial role in detoxification of drugs and poisonous by-products.

Golgi Apparatus:

Golgi apparatus consists of a system of membrane bounded vesicles arranged parallel to each other in stacks called Cisternae along with some large and spherical vacuoles. It was discovered by Camilo Golgi. In plants Golgi membrane is bounded. It is single membrane bounded. It is absent in prokaryotes, mammalian

RBC’s & sieve cells.

Functions of Golgi apparatus :

(a) It helps in formation of lipids.

(b) It helps in formation of middle lamellae.

(c) It is secretary in nature.

(d) It helps in melanin synthesis.

(e) Lipids and proteins synthesized in endoplasmic reticulum are

packed at Golgi complex. They provide the site for assembly of

new membrane material.