Saturday, May 30, 2020

Tissue class 9

Target audience :- Class 9th CBSE / other relevant board following NCERT
Topics to be covered:
*Introduction
*Difference between plants and animals
*Plant tissues
          -Types (2)
               +Meristematic tissue
               +Permanent tissue
*Animal tissues
          -Types(4)
               +Epithelial tissue
               +Connective tissue
               +Muscular tissue
               +Nervous tissue
-INTRODUCTION:-
In the last chapter we have discussed about cell . We have learnt
*Cell is the building block of life
*All organisms are made up of cells
*On the basis of number of cells, there are      two types of cells
      +Unicellular(Amoeba)
      +Multicellular(Homo sapiens)
#In Amoeba ,all the life processes ( digestion, respiration, transportation and excretion) are done by single cell.
#In Homo sapiens , division of labour occur.
  -In this cells aggregate to form tissue and thus perform specialised function very efficiently.
  -For example muscle cells contract and relax to cause movement,
  -Nerve cells carry messages and
  -Blood flow to transport Oxygen,food,           water and waste etcs.
DIFFERENCE BETWEEN PLANTS AND ANIMAL
• Plants are stationary(Do not move).
•Most of the tissues are supportive (provide  structural strength)
•Most of the tissues are dead( provide mechanical strength)
• Dead tissues need less maintenance.
• Growth is limited to certain regions.
• some cells divide throughout life Such cells are called meristematic cells and rest are of permanent type.
• structural organisation of Organ and Organ system is less complex.
Now let us figure out animals
•Show locomotion(movement from one place to another) in search of food , mate and shelter.
•Consume more energy
•Most of the tissues are living.
• Uniform growth occur upto certain age limit.
• No demarcation of dividing and non dividing region
• Structural organisation of Organ and Organ systems is more specialised.
They possess different life styles and so different kind of tissue
We will now learn about Plant tissues:-
*PLANT TISSUES
  Types (2)
      -Meristematic tissue
      -Permanent tissue
MERISTEMATIC TISSUE
- also known as dividing tissue
-growth of plant occur only in those regions where where these tissue present
-depening upon the region where they are present , it is of 3 types:-
     •Apical Meristematic tissue
     •Lateral meristematic tissue
     •Intercalary meristematic tissue (see fig.        6.2)
New cells formed from meristem are life of meristem itself , but as they grow they differentiate to form components of other tissues.
Differentiation :-the process by which Meristem take up permanent shape ,size and a function.
APICAL MERISTEM:-
Location:-gtowing tip of stems and roots
Function:--increases the lenght of stem and root
INTERCALARY MERISTEM-
Location:- base of leaves or internodes of twigs
LATERAL MERISTEM:-
Increases girth (thickness) of stem and root due lateral meristem(cambium)
CHARACTERISTICS OF MERISTEM:-
Possess dense cytoplasm,
•Thin cellulose wall,
•Prominent nucleus
• no storage of food so no vacuole
• no food so no disease
IMP:- used in tissue culture as they are diseases free cells.
PERMANENT TISSUE:-
Meristem differentiate to form different types of permanent tissue.
• Types :- 2
  - Simple permanent tissue
  -Complex permanent tissue
SIMPLE PERMANENT TISSUE
Made up of one type of cells.
Types :-3
   -Parenchyma
         +Aerenchyma
         +Chlorenchyma
   - collenchyma
   -Sclerenchyma
PARENCHYMA
Characteristics:-
-Unspecialised  cells(donot have special function ) with thin cell wall.
-Living cells
-Loosely arranged (large intercellular space)
-Generally store food.
-Location :- Beneath the epidermis.
*Types :- two types
1.Chlorenchyma
2. Aerenchyma
Chlorenchyma:-
-Paranchyma containing chlorophyll is called chlorenchyma.
-Perform photosynthesis.
Aerenchyma:-
-In aquatic plants , large air cavities are present in parenchyma to help them float.
-such parenchyma is called Aerenchyma.
COLLENCHYMA:-
Location:- found in leaves stalks below epidermis.
Characteristics:-
 -living,
- elongate ,
 -irregular thickening at the corners And
 -very little intercellular space
Functions:-
-Provide flexibility to plants.
-Allow bending in various parts of plants without breaking.
-provide mechanical support.

*SCLERENCHYMA:-
Location:-
-in stem around vascular bundle,
-In the veins of leaves,
-in the hard covering of seeds and nuts.
Characters:-
- cells are dead
-long and narrow
-walls are thicker due to lignin.
-No internal space inside the cell.
Functions:-
-Make the plant hard and stiff.
-provide strength to plant parts.

* EPIDERMIS:-
- outermost layer of cells.
-Usually made up of single layer of cells.
-entire surface of plants has an outer layer of epidermis.
-cells are continuous without intercellular space.
-epidermal cells are flat,
-outer and side walls are thicker than inner walls.
- protects all parts of plants.
Adaptation:-
-in very dry habitat epidermis may be thicker since protection against water loss is critical.
-Epidermal cells on the aerial parts of plants often secretes a waxy , water resistant layer On their outer surface
Functions:-
Aids in protection against lose of water,
Mechanical injury,
Invasion by parasitic fungi.
2.In desert plants, epidermis has a thick waxy coating of cutin on its outer surface.
Cutin is a chemical substance with waterproof quality.
Stomata:-
-Small pores here and there on the epidermis of leaf.
-enclosed by two kidney shaped cells called guard cells.
Functions:-
-Exchange of gases with atmosphere.
-Transpiration(loss of water from aerial parts of plants)

*Epidermis of roots:-
-bear long hair like parts that greatly increase the total absorptive surface area.
Function:-
Water absorption.
Secondary meristem:-
-As plants grow older, outer protective tissue undergoes certain changes
-A strip of secondary meristem, located in the cortex forms layers of cells which constitute the cork.
Characteristics:-
-cells of cork are dead , compactly arranged without intercellular spaces.
- have suberin in their walls that makes them impervious to gases and water.
mi

*Complex permanent tissue:-
- made up of more types of cells.
-All cells coordinate to perform common functions.
Types:- two types
1. Xylem
2. Phloem
-Both are conducting tissue contain vascular bundle
-Vascular russes is a distinct feature of complex plants.

Xylem:-
Consists of
1.Tracheids,
2. Vessels
3.Xylem parenchyma
4.Xylem fibres
Tracheids and vessels
- have thick walls and many are dead cells when mature.
-tubular structure
-transport water and minerals vertically.

Parenchyma stores food.

Xylem fibre are mainly supportive in functions.

Phloem :-
Consist of
1. Sieve cells,
2. Sieve tubes,
3.Companion cells,
4.Phloem fibre,
5. Phloem parenchyma.
- Sieve tubes are tubular cells with perforated walls.
- Phloem transports food from leaves to other parts of plants
-phloem fibres are dead
- others are living.

*ANIMAL TISSUES:-

-When we breathe we feel the movement of our chest.
-For this we have muscle cells.
- contraction and relaxation of muscle cells results in movement.
-During breathing we inhale oxygen.
- this oxygen absobed in lungs and is transported to all body cells through blood.
-In mitochondria , oxygen combine with glucose to make Carbon-di-oxide, water and ATP(adinosine triphosphate).
-Blood flows and carries various substances from one part of body to another.(oxygen ,food etc).
-also collect waste from  of all parts of body and Carries them to kidney and liver for disposal.
So blood and muscles are the russes in our body.
Four types of animal tissue in detail:-
1.epithelial tissue
2.connective tissue
3. Muscular tissue
4. Nervous tissue

Epithelial tissue:-
-Covering and protective tissue in animal body.
-Covers most organs and cavaties within the body.
-Forms a barrier to keep different system separate.
-skin, lining of mouth, lining of blood vessels, lung alveoli and kidney tubules are made up of epithelial tissue.
Characteristics:-
-cells are tightly packed and forms a continuous sheet
-have small amount of cementing material between them .
- no intercellular space.
Functions:-
Anything entering or leaving must cross atleast one layer of epithelium
-so permeability of epithelial play important role in exchanging material between body and external environment , also between different parts of body.
-different epithelial shows different structure and so different functions:-
-For example:-
1. Simple squamous epithelium:-
- cells are extremely thin and flat, forms a delicate lining.
-lining of oesophagus , mouth , blood vessels and lung alveoli.
2.Stratified squamous epithelium :- present in skin.
-prevent wear and tear.
When squamous epithelium are arranged in many layers then it is called stratified squamous epithelial.
3. Columnar epithelial:-
-In the inner lining of intestine, tall epithelial cells are present, called columnar epithelial cells.
-In respiratory tract, columnar cells have cilia, so called ciliated columnar epithelial .
- cilia push the mucus forward to clear the tract.
4. Cuboidal epithelial:-
- forms lining of kidney tubules and ducts of salivary glands.
-provide mechanical support.
5. Glandular epithelial:-
- A portion of epithelial tissue fold inward and a multicellular gland is formed , called glandular eplithilial tissue.

*Connective tissue:-
-Tissue which connects the body.
-example:- blood , bone, tendon ligament, adipose, cartilage and areolar.
- Cells are loosely spaced.
-Embedded in intercellular matrix.
- Matrix can be jelly like, fluid , dense or rigid .
- nature of matrix depends upon functions the tissue perform.
1.Blood:- fluid connective issue.
-Matrix is called plasma (fluid) in which RBCs , WBCs and platelets suspended.
- Plasma contains proteins , salts and hormones.
- Blood flows and transport gases, digested food , hormones and waste materials to different parts of body.
2. Bones:-
-strong and non- flexible tissue.
-Forms framework that supports the body.
- anchor the muscles
-support main Organs of the body.
- bone cells are embedded in hard matrix
- matrix compost of hard calcium and phosphorus compounds.
3.Ligament:- join bone to bone.
-elastic , has considerable strength.
- contain very little matrix.
4. Tendon:- join bone to muscle.
-fibrous tissue with great strength but limited flexiblity.
5.Cartilage:-
-widely spaced cells .
-Solid matrix composed of protein and sugar
-smoothen bone surface at joints.
-Present in nose , ear, trachea and laryings.
6.Areolar connective tissue:-
- Found between skin and muscles, around blood vessels and nerves and in bone marrow.
-fill space inside Organs,
-support internal organs.
-helps in repair of tissue.
7. Adipose tissue:-
-fat storing tissue.
-found below the skin and between internal organs.
-act as insulator.

*Muscular tissue:-
-Consists of elongated cells called muscle fibre
-responsible for movement in the body.
- Contains special protein called contractile proteins which contract and relax to cause movement.
Types:- three types
1.voluntory/skeletal/striated muscle
2.involulantory/unstriated muscle
3.Cardiac muscle
1.Voluntory /skeletal/Striated muscle:-
-cells are long, cylindrical, unbranched and multinucleate.
-can move by our conscious will(voluntary)
-attached to body skeleton (skeletal)
-under microscope , it shows alternate dark and light bands (Striated)
-found in limbs .
2.Involuntary /unstriated muscle:-
-cells are long with pointed ends(spindle shaped) and uninucleate.
- movement of food in alimentary canal or contraction and relaxation of blood vessels are the examples.
-we can't start or stop these movements by our own will.
- found in iris of eye, in uterus and in bronchi of lungs.
- no alternative dark or light band seen under microscope (unstriated).
3.Cardiac muscles:-
- muscles of heart shows rhythemic contraction and relaxation throughout life.
-cells are cylindrical, branched and multinucleate.

*Nervous tissue:-
-made up of nerve cells called neurons.
-One meter long cell.
-Highly specialised for being stimulated and then transmitting the stimulus very rapidly from one place to another within the body.
-brain , spinal cord and nerves are all composed of nervous tissue.
-parts of neuron:- three parts
1. Cell body(with nucleus and cytoplasm)
- possess many, short ,branched parts called dendrites.
2. Axon (single long part)
3. Nerve endings.

Many nerve fibres are bound together by connective tissue make up a nerve
- signal passes along nerve fibre is called nerve impulse.
-nerve impulse allow us to move our muscle when we want to.
-Functional combination of nerve and muscle tissue is fundamental to most animals.
-this combination enable animals to move rapidly in response to stimulus.

Thankyou :-)




Tuesday, April 28, 2020

Control and coordination

Control and coordination
Topics to be covered are:- 
1.Introduction,
 2.Animals –Nervous system.
 3.What happens in reflex action 4.Human brain
 5.How are these tissues protected 6.How does the Nervous tissue cause action?
 7.Coordination in plants 8.Immediate response to stimulus 9.Movement due to growth 10.Hormones in animals. Introduction:-
 •Recall the previous:-
 •Feature of alive:-
 •Movement
 •Growth
 •Seed germination
Why do we associate such visible movements with life?
• Because all these are a response to a change
•For example :-bright ligh is focussef on our eyes, the size of pupil gets reduce. 
•We whisper in class
Conclusion:- •All leaving organism respond to a change in the environment.
•The change in the environment to which organism respond is called stimuli such as light , heat , cold smell etc.
•Both plants and animals respond to stimuli but in different way.
System for control and coordination in animals:
•It includes 2 main stats:-
 Nervous system 
Endocrine  system
•Animals – Nervous system -
In animals control and coordination are provided by nervous and muscular tissue 
•Nervous system is made up of neurons 
-All information of stimuli is detected and conducted by specialised neurons present at the tip of sense organs.
 -Such neurons are called receptors  -It conduct information via electrical impulses from one part of body to another
On the basis of where the receptors present, it is of following types:
*Photoreceptor:-
 •Present in ear
 •Receive sound
•Help in hearing and maintaim balance of body.
 *Photoreceptor :-
•Present in eyes
•Receive Light 
•Help in seeing.
 *Thermoreceptors:-
 -Present in skin.
 -Feel temperature.
 -Help in feeling heat / cold and touch.
*Olfactory receptor:-
 -Present in nose.
 -sense of smell
 -help in detection of smell. *Gustatory receptors
 -present in tongue
 -Sense of taste.
 - help in detection of taste
Ques-What is neutron?
Ans:-Neuron is the structure And functional unit of nervous system. How neuron acquire and conduct information?
•What is the Functioning of neuron?
Functioning of neuron:- Neuron acquire information at the end of dendritic tip.
 •As chemical reaction takes place that create an electric impulse
•The impulse travel from dendrite to cell body and then at the end of axon passing through it
•At the end of axon , electrical impulse set off the release of some chemicals.
•These chemicals cross the synapse and start a similar electrical impulse in the dendrite of next neuron
•A similar synapse finally allow delivery of such impulses from neuron to other cells(eg muscle cells or gland). 
*Parts of neuron:-
•Dendrite
- Acquire Information.
•Cell body:- Information acquired is now travelled as an electrical impulse.
•Axon:-Longest fibre on cell body is called axon.
                 -Transmits electrical impulse from cell body to dendrite of        next neuron.

Synapse
Gap between nerve ending of one neuron and denrite of other neuron.
-Here electrical signals are converted into chemical signal for onward transmission.
Types of neuron:-
Sensory Neurons:- Neurons which transmit messages from body parts to CNS.
Motor Neurons:- Neurons which transmit messages from CNS to body parts.
Relay Neurons:- Neurons which relay the signals within CNS.
- Also called mixed neuron
*Reflex action:-
•It is sudden ,quick and automatic response to change in environment.
•Involves only spinal cord.
•Occur within fraction of seconds.:
•Example- knee jerk, withdrawal of hand on touching hot object.

Stimulus
Observable or detectabe change in external or internal environment to which an organism react.
Reflex arc :-
The path through which nerve impulses pass during reflex action is called reflex arc.
Heat(stimulus)-->Receptor(skin)--->Spinal cord--->Effector organ(muscle) -->Response(hand withdraw)

Response:- Final action after reflex action.
Voluntary and involuntary action
Voluntary action:- Action controlled by forebrain.
Example:- Walking , running, writing etc.
Involuntary action:- Actions controlled by mid brain and hind brain.
Example:- Beating of heart, digestion of food , breathing sweating ,working of kidney etc.
Need of reflex action:-
In some situations we need to act quickly otherwise our body would be harmed .
In these cases , response is generated from spinal cord instead of brain.
In this way ,time taken for action is reduced which save us from injury.
Some of these situations are touching a hot object , pinching etc.

Human brain
Main coordinating centre of body.
Consist of 3 parts:-
-Fore brain
-Mid brain
-Hind brain
Fore brain:-
Most complex and specialised part of brain
It consists of
•Olfactory lobe
•Cerebrum
•Diencephalon
Function:-
Olfactory lobe:-Centre for sense of smell.
Cerebrum:-receive sensory impulse from various receptors
Main seat for will power, intelligency memory , experience and conscious sensation and voluntary action.
Diencephalon:- Center for temperature regulation, hunger and emotional reaction.
Mid brain:- consist of 1. Optic lobe ,2. Crura cerebri
Functions:-
Optic lobe:- Centre of visual activities.
Control movement of eye ball and change in pupil size.
Crura cerebri:- Transmit impulse between fore brain and hindbrain.
Control reflex movement of head neck and trunk.
Hindbrain:- Consist of 1.Cerebellum 2. Pons varoli 3.medulla oblongata.
Functions:-
Cerebellum:- Maintain posture and equilibrium of body
Regulate voluntary movement.
Example:- picking pen, walking in a straight line.
Pons varoli:- control involuntary action.
Example respiration regulation
Medulla oblongata:- Control involuntary action .
Example:- Heart beat respiration ,blood pressure, coughing and sneezing etc.
Covering /Meanings of brain
Three menings- 1. Piameter2.Arachnoid membrane 3.Durameter.
Piameter :- innermost, extremely thin , delicate and vascular menings.
Arachnoid membrane:- Middle, thin vascular, give Webby appearance of spider.
Durameter:- Outermost, thick and fibrous layer.
Protection of brain :-

  • Brain is protected by hard bony structure called skull.
  • Along with this it is covered by 3 menings
  • Between piameter and arachnoid membrane, a clear alkaline fluid is present called cerebrospinal fluid
  • Functions of CSF:- Act as a shock absorber.
  • Forms a medium for exchange of nutrients and wastes among nerve tissue.
Protection of Spinal cord:- Spinal cord is protected by vertebral column called backbone.
How does Nervous tissue cause action?
  • When a nerve impulse reaches the muscles, muscles fibre move.
  • Muscle cells moves by changing their shape so that they shorten
How muscle fibre change their shape?
  • Muscle cell have special protein named Actin and Myosin.
  • When these proteins receive impulse their shape and arrangement in the cell change.
  • When this happens, new arrangement of these protein give muscle cells a shorten form.
Coordination in plants:-
Plants do not have nervous system.
Types of movement:-
Two types:-
1. Dependent on growth
2. Independent of growth
Independent of growth:-
  • It has immediate response to stimulus
  • Plants use electrical chemical means to convey information from cell to cell.
  • For movement to happen , cell change their shape by changing the amount of water in them, resulting in swelling or shrinking of cells.
  • Example:- Drooping of Touch me not plants on touching it
Dependent on growth:-
  • These movements are tropic movements(directional movement) in response to stimulus..
  • Tendrils:- pea plants climb up other support by tendrils.
  • Tendrils are sensitive to touch.
  • Part of tendril in contact with support grow slow as compare to part of tendril away from it.
  • This cause the tendril to circle around the object and cling to it.
  • Phototrophism :- growth of plant part towards sunlight. Shoot shows phototrophism.
  • Geotropism:- growth of plant parts toward earth Roots show geotropism.
  • Hydrotropism:-Growth of plant parts toward water. *Roots show hydrotropism.
  • Chemotropism :-growth of plant part towards chemicals example:- growth of pollen tube towards ovule.
Plant hormones:-
  • Chemical compound which help to coordinate growth , development and responses to environment.
  • Main plant hormones are :-
  • Auxin
  • Gibberelin
  • Cytokinins
  • Abscisic acid
Functions of hormones:-
Auxin:- Hormones synthesis at shoot tip.
Help the cell to grow longer.
Involved in photosynthesis.
Gibberellin:-Help in growth of stem.
Cytokinins:-Promote cell division.
Present in fruits and seeds in large concentration
Abscisic acid:-inhibit growth
Cause wilting of leaves.
Also known as stress hormones
Limitations of electric communication:-
  • Electric impulse reach to only those cells which are connected to nervous tissue.
  • Once an electric impulse is generated in a cell and transmitted, cell will take some time to reset it’s mechanism before it can generate and transmit a new impulse.
Note:-
  • Along with electric communication, animals also use another means of communication between cells named chemical communication.
  • Plant donot use electrical communication and use chemical communication only.
  • Mechanism of transporting impulse in plants.
  • When an impulse is received by cell , it releases a chemical compound
  • This compound would diffuse all around original cell.
  • It other cells around have the means to detect this compound using special molecules on their surfaces then they would be able to recognise information and even transmit it.
Hormones in animals:-
  • Chemical substances which coordination the activities of living organisms and also for their growth.
  • Hormones produced in one part of an organism move to another part to achieve desire effect.
  • Endocrine glands secretes their product (hormones into the blood.
  • List of endocrine gland with their hormones name And their functions are listed below:-

Importance of iodine:-
  • Iodised salt is necessary because iodine mineral is essential part of thyroxine hormones.
  • Thyroxine is released by thyroid gland.
  • Thyroxine regulates metabolism of carbohydrates, fats and proteins.
  • So we must consume iodised salt which is necessary for proper working of thyroid gland.
  • It’s deficiency causes a disease called goiter.
  • Diabetes
  • Due to deficiency of insulin hormones
  • Insulin is secreted by Pancreas.
  • Insulin is responsible to control blood sugar levels.
  • Treatment :-Injections of insulin hormones can be helpful.
Feedback mechanism:-
  • The excess or deficiency of hormones has a harmful beffect on our body.
  • Feedback mechanism makes sure that hormones should be secreted in precise quantity and at right time.
  • Example:- Feedback mechanism to control the sugar level in blood as follows:-

Important ques assignment:--
  • write in detail about animals nervous system .
  • What are receptors And it’s types?
  • What is neuron? Write about functioning of neuron.
  • Write about parts of neuron.
  • What are the types of neuron?
  • What is reflex action?
  • Define :- stimulus, reflex arc and response.
  • What is the need of reflex action?
  • What is voluntary and involuntary action?
  • Draw and give a detain about CNS.
  • How is brain protected?
  • How muscle fibre change their shape?
  • Give a detail account of coordination in plants.
  • Define :- Phototrophism, geotropism, hydrotropism and chemotropism
  • What are plant hormones? Explain in detail.
  • What are animal hormones? Explain in detail.
  • What is the importance of iodine?
  • What is diabetes?
  • What is feedback mechanism?



Tuesday, March 17, 2020

Maa o maa poem

बेटी

 

माँ माँ .. मै तेरी लाडो माँ !

आने दे तेरी बगिया में मुझे ,

मै भी फूल गुलाबो माँ !

माँ माँ ... मै तेरी लाडो माँ !!!

 

परी तू मेरी, ताज पापा का ,

दिल का टुकड़ा, लाज दादा का !

 

डरती क्यों फिर? माँ माँ,

मम्मा.... मैं तेरी लाडो हू मम्मा !!!

 

डर लगता है समाज का .. डरा देती है ये दुनिया ,

दहेज में ना जला दे तुझे.. झुकना ना सीख दे कोई तुझे !

 

रिश्तों में उलझी दुनिया में ,

लाना मै भी चाहती हूं ..बिटिया है मेरी तू बताना मै भी चाहती हूं !

फिर बिकती दुनिया को देख डर लगता है ,

मांगती दुनिया में केसा हम्सफ्र होगा ?

लाडो दिल का टुकड़ा तू मेरा !

 

माँ मेरी माँ ...

पढ़ना देना ... लिखा देना ,

 लाडो मै तेरी .. मुझे लायक बनाना देना ,

सोना चांदी मुझे हिला ना सके ,

खुद पर विश्वास करना सिखा देना माँ !

मम्मा.... मैं तेरी लाडो हू मम्मा !!!

 


Beti 

Maa o maa ..Mai Teri laado maa
Aane de Teri bgiya me mujhe
Mai bhi fool gulabo maa
Maa o maa ..Mai Teri laado maa

Pari tu meri ,taaj h papa Ka
Dil Ka tukra , laaj h daada Ka

Drti kyo fir  maa o maa
Mumma mai Teri laado Hu mumma

Drr lgta h smaj Ka .. drr deta ye sma
dahej me naa jla de tujhe .. jhukna na seekha de koi tujhe

Rishton me ulljhi is duniya me
Laana Mai bhi chahti hu ..bitiya h meri Tu btana Mai bhi chahti Hu
Fir bikti duniya ko dekh Drr lgta h
Mangti duniya me kesa hmsfr Hoga
Laado Dil Ka tukra Tu Mera

Maa or meri maa .. pda dena Likha dena ... Laado Mai Teri .. layk bna dena
Sona chandi mujhe hila na ske ..
Khud pr vishva krna sikha dena mumma

Maa o maa Mai Teri laado Hu maa