Biology · Science General

Cell Biology and Structure

3,062 Questions

Cell biology focuses on the structure and function of cellular organelles. Key topics include cellular respiration, DNA inheritance, and energy production. These fundamental biology concepts are crucial for medical entrance and state service examinations.

Cell organelles functionsCellular respiration sitesDNA and ribosomesAnimal cell structurePlant cell components

Cell Biology and Structure Questions

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

Choose the incorrect statement.

  1. Permanent tissues having all cells similar in structure and function are called simple tissue.

  2. Complex tissue has different types of cells performing different functions altogether.

  3. Secondary meristem is lateral meristem.

  4. The cells of permanent tissues divide further.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

  • Permanent tissues may be defined as a group of living or dead cells formed by meristematic tissue and have lost their ability to divide and have permanently placed at fixed positions in the plant body. Meristematic tissues that take up a specific role lose the ability to divide. This process of taking up a permanent shape, size and a function is called cellular differentiation. Cells of meristematic tissue differentiate to form different types of permanent tissues.
Simple tissues - A group of cells which are similar in origin; similar in structure and similar in function are called simple permanent tissue.
  • Complex permanent tissue - The complex tissue consists of more than one type of cells which work together as a unit. Complex tissues help in the transportation of organic material, water and minerals up and down the plants. That is why it is also known as conducting and vascular tissue.
  • Lateral Meristem - This meristem consists of cells which mainly divide in one plane and cause the organ to increase in diameter and growth. Lateral meristem usually occurs beneath the bark of the tree in the form of Cork Cambium and in vascular bundles of dicots in the form of vascular cambium. The activity of this cambium results in the formation of secondary growth.

So the correct option is 'The cells of permanent tissues divide further'.

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

Stone cells is an alternative name of 

  1. Cortical fibres

  2. Sclereids

  3. Xylary fibres

  4. Phloem fibres
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A. Cortical fibres are the extraxylary fibres present in cortex.

B. Sclereides are excessively thick walled short sclerenchyma cells.

C. Xylary fibres are the sclerenchyma fibres present in the xylem.

D. Phloem fibres are the sclerenchyma fibres present in the phloem.

So the correct answer is ‘sclereids’.

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

Which simple permanent tissue is formed of dead cells?

  1. Collenchyma

  2. Sclerenchyma

  3. Aerechyma

  4. Xylem
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Collenchyma, is the simple permanent mechanical tissue, formed of living cells. 

Sclerenchyma, is the simple permanent mechanical tissue, formed of dead cells.

Aerenchyma, is a type of parenchyma, simple permanent tissue, formed of living cells.

Xylem is a simple complex permanent tissue formed of the majority of dead cells. 

So, the correct answer is ‘Sclerenchyma’.

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

Sclerenchymatous cells in their cell walls have large percentage of

  1. Cellulose

  2. Pectin

  3. Lignin

  4. Silica
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sclerenchyma is a simple permanent tissue which is mainly composed of dead cells. The walls consist of cellulose, hemicellulose and lignin. These are the principal supporting cells in plant tissues that have ceased elongation. 

So, the correct answer is option C.

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

Which of the following is/are composed of dead cells?

  1. Sclerenchyma

  2. Tracheids

  3. Vessels

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • Sclerenchyma cell is a simple permanent tissue which is mainly composed of dead cells. It provides strength and rigidity to the stem. 
  • It forms the protective covering of nuts and fruits. Their cell walls contain, besides cellulose, a high proportion of lignin. 
  • It forms a protective coating on seeds and nuts.

Therefore, the correct answer is option A.

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

Which cells among the permanent tissue are impermeable to water?

  1. Parenchyma

  2. Collenchyma

  3. Both A and B

  4. Sclerenchyma
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The chief mechanical tissue of the plant body composed of highly thick walled cell with little or no protoplasm is called as sclerenchyma. Sclerenchyma consist of lignin. Lignin deposition is so thick that the cell walls become strong, rigid and impermeable to water. 

Therefore, the correct answer is option D.

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

Which of the following tissues is dead at maturity?

  1. Sclerenchyma

  2. Collenchyma

  3. Parenchyma

  4. Both B and C
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The chief mechanical tissue of the plant body composed of highly thick walled cell with little or no protoplasm is called as sclerenchyma. The thickening of cell wall is due to deposition of cellulose or lignin or both. Lignin deposited cells are said lignified. Sclerenchyma cells are dead at maturity because of the absence of protoplast. 

Therefore, the correct answer is option A.

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

The cells of sclerenchyma can be classified as

  1. Fibres and fibriosis

  2. Ligaments

  3. Fibre and sclereids

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The chief mechanical tissue of the plant body composed of highly thick walled cell with little or no protoplasm is called as sclerenchyma.

The cells of sclerenchymatous cells can be classified as:
1. Fibres- Fibres are long, elongated sclerenchymatous cells with pointed ends.
2. Sclereids- Sclerenchymatous cells which are short and possess extremely thick lignified walls. 
Therefore, the correct answer is option C.

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

The sclerenchyma cells are thick walled due to the presence of

  1. Acetone

  2. Lignin

  3. Lipids

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The chief mechanical tissue of the plant body composed of highly thick walled cell with little or no protoplasm is called as sclerenchyma. The thickening of cell wall is due to deposition of cellulose or lignin or both. Lignin deposited cells are said lignified.

Therefore, the correct answer is option B.

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

The tissue which has dead cells in the functional state is

  1. Collenchyma

  2. Sclerenchyma

  3. Parenchyma

  4. Phloem
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Sclerenchyma cells are dead cells at maturity and have a very thick cell wall due to the deposition of lignin. 
  • They are either present in the form of fibres or sclereids (stone cells).
  • They are located in the leaf veins, hard coverings of the seeds and vascular bundle. 
  • Its main function include- 1) provide rigidity and mechanical support to the plant body, 2) It also makes the plant stiff and hard.
  • So, the correct answer is 'Sclerenchyma'.
Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

Which of the following tissues has dead cells?

  1. Parenchyma

  2. Sclerenchyma

  3. Collenchyma

  4. Epithelium
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Parenchyma cells have thin cellulosic cell walls. Collenchyma cells have thicker cellulosic walls and also may have pectin deposition on corners. Sclerenchyma cells have thick lignified cell walls and are dead at maturity and provide protection to the different parts of the body. Epithelial cells are thin-walled and living.

So, the correct answer is option B.

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

Intercellular spaces are absent in sclerenchymatous tissues because___________.

  1. They are stratified.

  2. They are lignified.

  3. They are classified.

  4. They are columnar.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Walls of sclerenchyma cells are lignified, which make them thick. Due to this, are no intercellular spaces between them. Hence, option B is correct.