Cell wall

The cell wall is a thick rigid protective layer surrounding all plant cells except gametes and zoospores. This note contains detail information about cell wall of the eukaryotic cell.

Summary

The cell wall is a thick rigid protective layer surrounding all plant cells except gametes and zoospores. This note contains detail information about cell wall of the eukaryotic cell.

Things to Remember

  • The cell wall is a thick rigid protective layer surrounding all plant cells except gametes and zoospores.
  • Beside plants, it occurs in fungi, bacteria, blue-green algae etc but it is completely absent in an animal cell.
  • Plasmodesmata are cytoplasmic connections or bridges present between two adjoining cells. 
  • The chemical composition of the secondary wall is cellulose, hemicellulose, pectin and extra chemical compound like lignin. 
  • The cell wall of leaf cells prevents excessive transpiration.It also carries out enzymatic activities.

 

 

 

 

 

MCQs

No MCQs found.

Subjective Questions

Q1:

How can we control poultry diseases?


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>We can control poultry diseases by vaccinating on time, providing medicines according to the disease, and paying attention to the kind of problems they are getting. Also, caring about their health and managing proper&nbsp;hygiene, pasture and environment are important.</p>

Q2:

What are the main diseases of poultry birds?


Type: Long Difficulty: Easy

Show/Hide Answer
Answer: <p>The main diseases of poultry birds are as follows:</p>
<p><strong>Bird Flu:</strong> Bird flu is a viral infection spread from the bird. The red spot appears on the body and yellow stool is discharged. This can also be transmitted to human, so we must be careful.</p>
<p><strong>Habitual Vices:</strong> Eating the flesh, eating eggs and hiding eggs are the habitual vices of poultry birds. Such habits are formed due to inappropriate spacing and wrong feeding.</p>
<p><strong>New Castle Disease:</strong> It is a viral disease. After infection, the whole stock should be killed and buried and the house must be disinfected.</p>
<p><strong>Infection Bursal Disease (IBD):</strong> It is also a viral disease. Birds should be vaccinated timely.</p>
<p><strong>Coccidiosis:</strong> It is caused by some species of protozoa and it is a widely spread disease in poultry.</p>

Q3:

How will you do production management of poultry birds?


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>Production management of poultry birds can be done by keeping up to date records of the following aspects:</p>
<ul>
<li>The record of capital goods</li>
<li>Income and expenditure records</li>
<li>Meat and egg production records</li>
<li>Feed and medicines purchase and consumption records</li>
<li>Growth record of the birds</li>
</ul>

Q4:

Write short notes on feeding management.


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>The feed should contain the proper amount of vitamins, minerals, fats, carbohydrates and water for the growth and proper development of chickens. Feeding management is a very important activity in commercial poultry farming. For the poultry farming, 70% of investment is required for poultry farming feed. Proper feeding is required for the proper development of the farming.</p>

Q5:

How can feed be prepared from local materials for poultry birds?


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>In readymade feed, a&nbsp;vitamin-mineral premix is added into all kinds of feed. Particular selection and the combination of food sources should be made out of the nutrients to prepare balanced feeding. We can add the local materials like maize, wheat, bran etc.</p>

Q6:

What things are to be considered while feeding poultry birds?


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>While feeding poultry birds, all kinds of nutrients (carbohydrates, fats, proteins, minerals, vitamins and water) are to be considered.</p>

Q7:

Explain the life cycle of poultry birds.


Type: Long Difficulty: Easy

Show/Hide Answer
Answer: <p>The life cycle of a chicken begins with eggs. A hen lays about one egg per day. But, it stops laying the eggs in winter until spring. The eggs should be fertile for breeding. Fertilized eggs are collected and set to brooding with clean and dry litter. Mother hen then keeps on embracing the eggs with wings to keep it warm, which is called incubation. The yolk inside the egg supplies the food to the embryo and it grows to become a chick. When a chick is grown for 21 days and is &nbsp; strong &nbsp;enough it open its shell of the egg and comes out. This process is called hatching. A female chick is called hen and a male is called a rooster.</p>
<p>But in this modern day poultry farming, incubation and hatching of fertile eggs are obtained from breeding stocks and set to the incubator for 18 days and then to hatching machine for 5 days.</p>

Q8:

What do you mean by nutrients and balanced diet of poultry birds?


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>Nutrients can be classified into six categories- carbohydrates, fats, proteins, minerals, vitamins and water. The first two are required for energy and the later four are required for growth, maintenance, and vitality. Providing such nutrients is known as a balanced diet of poultry birds.</p>

Q9:

What is the  percentage of meat sector that is contributed by chickens?


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>It is estimated that nearly 50% of meat sector is contributed by chickens.</p>

Q10:

Give the symptoms and preventive methods of New Castle Disease?


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>New Castle Disease is a viral disease. The symptoms are respiratory problems, neck and body twisting, green stool and high fever, etc. Treatment of this disease is impossible. After infection, the whole stock should be killed and buried and the house must be disinfected.</p>

Videos

poultry farming in nepal
Poultry Farming
poultry farming training
Poultry farming
Cell wall

Cell wall

Cell wall

cell wall

source:www.buzzle.com

The cell wall is a thick rigid protective layer surrounding all plant cells except gametes and zoospores. Beside plants, it occurs in fungi, bacteria, blue-green algae etc but it is completely absent in an animal cell.

Structure of Plant cell wall

Structure of Plant cell wall
source:en.wikipedia.org

fig:Structure of Plant cell wall

It consists of following important parts;

  • Primary wall
  • Secondary wall
  • Middle lamella
  • Plasmodesmata

Primary wall

It is present in all growing living plant cell. But only this wall layer is present in a certain plant cell. eg; Parenchyma. It is thin, elastic and lies inner to the middle lamella. Its thickness may range to 1-3µm (micron). It is chemically composed of cellulose, hemicellulose, and pectin. It consists of loosely arranged cellulose microfibrils which remain embedded in the matrix of hemicellulose, pectin, and water.

Secondary wall

It is present or formed only in certain mature non-dividing or dead cells. Eg; cork cells, sclerenchyma, tracheids, vessels. It lies inner to the primary wall and is thick and inelastic in nature. Its thickness may range from 5-10µ. The chemical composition of a secondary wall is cellulose, hemicellulose, pectin and extra chemical compound like lignin. It consists of closely arranged cellulose microfibrils in the matrix.

Middle lamella

It lies in between the primary walls of two adjoining cell. It is also called cementing layer which joins the cell together. It is chemically composed of calcium and magnesium pectates.

Plasmodesmata

Plasmodesmata are cytoplasmic connections or bridges present between two adjoining cells. These connections are present in small pores across the cell wall. They help to transfer the substances across the cell and also give cytoplasmic continuity to the cells.

Function of cell wall

  • It protects inner contents of cells.
  • It gives mechanical support and rigidity to the cell.
  • It gives shape to the cell.
  • It prevents undue expansion of the cell.
  • The cell wall of root hairs helps in the absorption of water and minerals.
  • It prevents osmotic bursting of the cell.
  • The cell wall of leaf cells prevents excessive transpiration.
  • It also carries out enzymatic activities.

Lesson

Cell

Subject

Biology

Grade

Grade 11

Recent Notes

No recent notes.

Related Notes

No related notes.