Saturday, 6 August 2011

CBSE Class IX ( 9th) Science | Chapter 6. Tissues | Lesson Exercises

Question 1. Define the term tissue.
Answer : Tissue may be defined as a group or cluster of cells that are similar in structure and work together to achieve a particular function.Tissue as a cluster of cells performs a particular function at a definite place in the body.With in a tissue, cells are arranged or designed to give the highest possible efficiency of function. Blood, phloem and muscle are all examples of tissues.

Question 2. How many types of elements together make up the xylem tissue?
Name them.

Answer : Xylem tissue are Complex tissues, which are made of more than one type of cells. Xylem tissue consists of tracheids, vessels, xylem parenchyma and xylem fibres. The cells have thick walls, and many of them are dead cells. Tracheids and vessels are tubular structures. This allows them to transport water and minerals vertically. The parenchyma stores food and helps in the sideways conduction of water. Fibres are
mainly supportive in function.

Question 3. How are simple tissues different from complex tissues in plants?
Answer :

Differences between simple and complex tissues in Plants
Simple TissueComplex Tissue

These are made up of only one type of cells, which look like each other.
All cells have common origin and structure.
They are called epidermis .
Their main role is to store and provide structural support.
Examples— Collenchyma, Parenchyma and sclerenchyma.

These are made up of more than one type of cells.
The cells of complex tissues have different origin as well as structure.
They are called vascular tissue .
Their main function is transport of water, minerals, sugars and other metabolites.
Examples— Xylem and phloem.

Question 4. Differentiate between parenchyma, collenchyma and sclerenchyma on the basis of their cell wall.
Answer :

Differences between parenchyma, collenchyma and sclerenchyma on the basis of their cell wall
Parenchymacollenchymasclerenchyma

The cell wall is thin and is made up of cellulose.

The cell wall is thick due to deposition of lignin.
The cell wall is thick at the corners due to deposition of pectin.

Question 5. What are the functions of the stomata?
Answer : Stomata are small pores present in the epidermis of the leaf. Stomata are enclosed by two kidney-shaped cells called guard cells.
The main function of stomata are :
They are necessary for exchanging gases like Co2 or O2 with the atmosphere. Photosynthesis is not possible without them.
They are responsible for Transpiration in which water is lost in the form of water vapour from the plant surface. This ultimately helps in absorption of minerals by root tissues on account of build up root pressure.

Question 6. Diagrammatically show the difference between the three types of muscle fibres.
Answer :
Types of Muscles FibreS

Question 7. What is the specific function of the cardiac muscle?
Answer : The specific function of cardiac muscle to contract and relax rhythmically throughout life and to ensure the blood circulation through entire body.Heart muscle cells are cylindrical, branched and uninucleate.

Question 8. Differentiate between striated, unstriated and cardiac muscles on the basis of their structure and site/location in the body.
Answer :
Differences Striated, Unstriated and Cardiac Muscles
Striated Muscle Unstriated Muscle Cardiac Muscle

The fibres or cells are long and cylindrical.
The fibres or cells are un-branched.
Multiple nuclei are present on the periphery.
Striations with light and dark band present.
They are present in Hand, feet and other skeletal muscles.
The cells are long, narrow, spindle-shaped.
The fibres or cells are unbranched.
Single centrally located nucleus.
Striations absent.

They are present in Walls of stomach, intestine, ureter and bronchi.

The cells are short, cylindrical and branched.
At some places, they develop lateral outgrowths to form cross-connections.
Cardiac cell are uninucleate and have a centrally located single nucleus
Striations present, but not as prominent as they are present in striated muscle.
They are present in the heart.


Question 9. Draw a labelled diagram of a neuron.
Answer : 
Labelled Diagram of a Neuron


Question 10. Name the following.
(a) Tissue that forms the inner lining of our mouth.
(b) Tissue that connects muscle to bone in humans.
(c) Tissue that transports food in plants.
(d) Tissue that stores fat in our body.
(e) Connective tissue with a fluid matrix.
(f) Tissue present in the brain.

Answer :
(a) Tissue that forms the inner lining of our mouth --- Squamous epithelium
(b) Tissue that connects muscle to bone in humans - Tendon
(c) Tissue that transports food in plants - Phloem
(d) Tissue that stores fat in our body - Adipose tissue
(e) Connective tissue with a fluid matrix - Blood
(f) Tissue present in the brain - Nervous tissue


Question 11. Identify the type of tissue in the following: skin, bark of tree, bone, lining of kidney tubule, vascular bundle.
Answer : 
Given Type of tissue

Skin

Bark of tree

Bone

Lining of kindey tubule

Vascular bundle
Squamous epithelium

Cork or secondary epidermis (tissue)

Connective tissue

Cuboidal epithelium

Conductive tissue (xylem and phloem)


Question 12. Name the regions in which parenchyma tissue is present.
Answer : Parenchyma tissue are cluster of living cells . They consists of relatively
unspecialised cells with thin cell walls. They are usually loosely packed and have large
intercellular spaces. This tissue is mainly found in all soft parts of the plant such as stem, root, leaves, flowers, fruits. It is also found in the ground tissue of petioles, mesophyll of leaves as well as in vascular bundles.

Question 13. What is the role of epidermis in plants?
Answer :
Role of epidermis in plants :
1. Protection of the underlying cells and tissues.
2. Prevention of water loss.
3. Prevention of mechanical injury and invasion by parasite fungi.
4. Absorption of water.
5. Exchange of gases and transpiration through stomata.

Question 14. How does the cork act as a protective tissue?
Answer : Cork is a multi layered structure of of epidermal. These cells are dead and compactly arranged without intercellular space. They also have a chemical called suberin in their walls which makes them impervious to water and gases.

Question 15. Complete the table:

Chapter 6. Tissues CBSE Class IX ( 9th) Science - Question 15



 Answer :

 Chapter 6. Tissues  | Question 15 : Answer | CBSE Class IX ( 9th) Science |


10 comments:

  1. This is awesome ... Helped me a lot in finishing my h/w , and also helped in increasing my FA grades ... :) :D ...

    ReplyDelete
  2. This is simply....magneficant .....

    Hats off¡

    ReplyDelete
  3. bless you,,,,, so helpfull,,,, i lost my bio copy and this helped me a lot...... nice work

    ReplyDelete
  4. you can also prepare ppt but it is very help full for me!!!

    ReplyDelete
  5. It helps a lot for my unit test prepration

    ReplyDelete
  6. last table is incorrect. sclerenchyma comes under simple permanent tissue

    ReplyDelete
  7. this is awesome but one thing is incorrected u
    in last table scelerenchyma comes in simple permanent tissue

    ReplyDelete
  8. Awsm it really helped my daughter
    Adorable

    ReplyDelete