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Page No 79: - Chapter 6 Tissues class 9 ncert solutions Science - SaraNextGen [2024]


Question 1:

Define the term “tissue”.

Answer:

Tissue is a group of cells that are similar in structure and are organized together to perform a specific task.

 

Question 2:

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

Answer:

There are four different types of cells that make up the xylem tissue. They are:

(i) Tracheids

(ii) Vessels

(iii) Xylem parenchyma

(iv) Xylem fibres

 

Question 3:

How are simple tissues different from complex tissues in plants?

Answer:

Simple tissue

Complex tissue

These tissues consist of only one type of cells.

These tissues are made up of more than one type of cells.

The cells are more or less similar in structure and perform similar functions.

Different types of cells perform different functions. For example, in the xylem tissue, tracheids help in water transport, whereas parenchyma stores food.

Three types of simple tissues in plants are parenchyma, collenchyma, and sclerenchyma.

Two types of complex permanent tissues in plants are xylem and phloem.

Question 4:

Differentiate between parenchyma, collenchyma and sclerenchyma, on the basis of their cell wall.

Answer:

Parenchyma

Collenchyma

Sclerenchyma

Cell walls are relatively thin, and the cells in parenchyma tissues are loosely packed.

The cell wall is irregularly thickened at the corners, and there is very little space between the cells.

The cell walls are uniformly thickened, and there are no intercellular spaces.

The cell wall in this tissue is made up of cellulose.

Pectin and hemicellulose are the major constituents of the cell wall.

An additional layer of the cell wall composed mainly of lignin is found.

Question 5:

What are the functions of the stomata?

Answer:

Functions of the stomata:

(i) They allow the exchange of gases (CO2 and O2) with the atmosphere.

(ii) Evaporation of water from the leaf surface occurs through the stomata. Thus, the stomata help in the process of transpiration.

 

Question 6:

Diagrammatically show the difference between the three types of muscle fibres.

Answer:

The three types of muscle fibres are:Striated muscles, smooth muscles (unstriated muscle fibre), and cardiac muscles.

 

https://img-nm.mnimgs.com/img/study_content/curr/1/9/8/118/936/Chapter%206_html_m56470d94.jpg

Striated muscle fibres

 

https://img-nm.mnimgs.com/img/study_content/curr/1/9/8/118/936/Chapter%206_html_m57035486.jpg

Unstriated muscle fibres

 

https://img-nm.mnimgs.com/img/study_content/curr/1/9/8/118/936/Chapter%206_html_m7fff37fe.jpg

Cardiac muscle fibres

Question 7:

What is the specific function of the cardiac muscle?

Answer:

The specific function of the cardiac muscle is to control the contraction and relaxation of the heart.

 

Question 8:

Differentiate between striated, unstriated and cardiac muscles on the basis of their structure and site/location in the body.

Answer:

Striated muscle

Unstriated muscle

Cardiac muscle

On the basis of structure:

Cells are cylindrical

Cells are long

Cells are cylindrical

Cells are not branched

Cells are not branched

Cells are branched

Cells are multinucleate

Cells are uninucleate

Cells are uninucleate

Alternate light and dark bands are present

There are no bands present

Faint bands are present

Its ends are blunt

Its ends are tapering

Its ends are flat and wavy

On the basis of location:

These muscles are present in body parts such as hands, legs, tongue, etc.

These muscles control the movement of food in the alimentary canal, the contraction and relaxation of blood vessels, etc.

These muscles control the contraction and relaxation of the heart

Question 9:

Draw a labelled diagram of a neuron.

Answer:

https://img-nm.mnimgs.com/img/study_content/curr/1/9/8/118/963/Chapter%206_html_18a5f695.jpg

Structure 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 → Epithelial tissue

(b) Tissue that connects muscle to bone in humans → Dense regular connective tissue (tendons)

(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:

Skin: Stratified squamous epithelial tissue

Bark of tree: Simple permanent tissue

Bone: Connective tissue

Lining of kidney tubule: Cuboidal epithelial tissue

Vascular bundle: Complex permanent tissue

Question 12:

Name the regions in which parenchyma tissue is present.

Answer:

Leaves, fruits, and flowers are the regions where the parenchyma tissue is present.

 

Question 13:

What is the role of epidermis in plants?

Answer:

Epidermisis present on the outer surface of the entire plant body. The cells of the epidermal tissue form a continuous layer without any intercellular space. It performs the following important functions:

(i) It is a protective tissue of the plant body

(ii) It protects the plant against mechanical injury

(iii) It allows exchange of gases through the stomata

 

Question 14:

How does the cork act as a protective tissue?

Answer:

The outer protective layer or bark of a tree is known as the cork. It is made up of dead cells. Therefore, it protects the plant against mechanical injury, temperature extremes, etc. It also prevents the loss of water by evaporation.

 

Question 15:

Complete the table:

https://img-nm.mnimgs.com/img/study_content/curr/1/9/8/118/982/Chapter%206_html_m2560ac79.jpg

Answer:

https://img-nm.mnimgs.com/img/study_content/curr/1/9/8/118/982/Chapter%206_html_mae6f7d9.jpg

Also Read : INTRODUCTION-Chapter-7-Diversity-In-Living-Organisms-class-9-ncert-solutions-Science

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