Tag: permanent tissue

Questions Related to permanent tissue

A column of water within xylem vessels of tall trees does not break under its weight because of 

biology transport in plant transport in the phloem of plants vascular tissue permanent tissue

  1. Dissolved sugar in water

  2. Tensile strength of water

  3. Lignification of xylem vessels

  4. Positive root pressure

Show answer
Correct Option: B
Explanation:

Positive root pressure pushes up the water. 

Lignification of xylem vessels provide mechanical support.
Dissolved sugar in water reduces it's water potential but has no role in maintaining a column.
Tensile strength of water is its ability to resist the break in column due to forces like the transpiration pull. This is achieved by properties of water like Cohesion and Adhesion.
So the correct answer is 'Tensile strength of water'.

Which of the following statement is true?

biology transport in plant transport in the phloem of plants vascular tissue permanent tissue

  1. Vessels are multicellular with wide lumen.

  2. Tracheids are multicellular with narrow lumen.

  3. Vessels are unicellular with narrow lumen.

  4. Trachieds are unicellular with wide lumen.

Show answer
Correct Option: A
Explanation:

Vessels are multicellular with wide lumen. They are made up of vessel  elements lying one above the other. The wall of vessels is hard but not thick having wide lumen. Whereas tracheids are unicellular with narrow lumen. 

Thus, the correct answer is 'Vessels are multicellular with wide lumen'.

Radial conduction of water and food material in the woody stems is the functions of.

biology transport in plant transport in the phloem of plants vascular tissue permanent tissue

  1. Endodermis

  2. Xylem fibres

  3. Vessels

  4. Vascular rays

Show answer
Correct Option: A

Epidermis is specialised for.

biology transport in plant transport in the phloem of plants vascular tissue permanent tissue

  1. Respiration

  2. Absorption

  3. Protection

  4. All the above

Show answer
Correct Option: C

Unidirectional flow of water, minerals, some organic nitrogen and hormones occurs through

biology transport in plant transport in the phloem of plants vascular tissue permanent tissue

  1. Xylem

  2. Phloem

  3. Root

  4. Vascular tissue

Show answer
Correct Option: A
Explanation:
There are two types of vascular tissues in plants, xylem and phloem, xylem translocation is mainly from roots to aerial parts. It passes water with mineral salts, some organic nitrogen and hormones. Phloem translocates organic substances and some inorganic solutes first from leaves to all other parts of the plant and storage organs. Storage organs reexport organic nutrients to those parts which require the same, such as newly formed leaves and fruits.
So, the correct answer is 'Xylem'.

Ringing/girdling experiments demonstrate

biology transport in plant transport in the phloem of plants vascular tissue permanent tissue

  1. Phloem is responsible for translocation of food

  2. Xylem is responsible for ascent of sap

  3. Transpiration pull

  4. Both A and B

Show answer
Correct Option: A
Explanation:

Ringing/Girdling experiments demonstrate that phloem is responsible for translocation of food because phloem is present outside to xylem so when a ring of bark is removed from a woody plant, the woody xylem part remains intact, water and nutrient reaches the leaves. After the preparation of the photosynthate, it is not transported to other parts below the girdle since the phloem part is removed. This experiment shows that the phloem tissue aids food transport.

So, the correct option is A.

State an incorrect statement w.r.t. phloem transport 

biology transport in plant transport in the phloem of plants vascular tissue permanent tissue

  1. Translocation is variable so transport is unidirectional

  2. Translocation of sucrose and water occurs through companion cells only

  3. Phloem sap is slightly alkaline

  4. Phloem is cutout to prove its role in translocation during girdling experiment

Show answer
Correct Option: A
Explanation:

Xylem flow is unidirectional and phloem flow is bidirectional because xylem transport water from soil to leaves and phloem transfers the food.

Plant transfers glucose in the form of sucrose in order to

biology transport in plant transport in the phloem of plants vascular tissue permanent tissue

  1. Increase energy storage

  2. Provide efficient energy transfer

  3. Remove it in between reactions

  4. All of the above

Show answer
Correct Option: D
Explanation:

Starch and sucrose are more efficient forms in which the energy can be stored when compared to glucose. The starch is not soluble in water. Hence, the sucrose which is soluble in water is the form which is used for transport. This structural form increases the efficient energy transfer. Sucrose is not as reactive as glucose. This helps to prevent the chemical reactions which can convert the sucrose while transport. 

Thus, the correct answer is option D. 

In which season, sugar in the leaves will be readily consumed?

biology transport in plant transport in the phloem of plants vascular tissue permanent tissue

  1. Autumn

  2. Spring

  3. Winter

  4. None of the above

Show answer
Correct Option: B
Explanation:

Spring is considered as the flowering season. This is the period when there is growth of the floral buds which are formed at the apex of the vegetative shoots. Generally, there is a flow of sugar from the source (leaves) to sink end (roots). Due to the increase in the activity in the apex regions of the plant, there is consumption of food in the leaves. Hence, the food to the flower buds is supplied by the roots. 

Thus, the correct answer is option B. 

Phloem parenchyma acts like

biology transport in plant transport in the phloem of plants vascular tissue permanent tissue

  1. Transfer cells

  2. Packaging material

  3. Conducting cells

  4. Both A and B

Show answer
Correct Option: D
Explanation:
The parenchyma cells in the phloem tissue are known as phloem parenchyma. There are different types of phloem parenchyma cells, companion cells, albuminous and other parenchyma cells. The transfer cells are a type of companion cells. These are the cells which have folded cell wall surface which help in scavenging the solutes which require ATP to move across the membranes. 
The parenchyma cells act as packaging material. These cells fill the gaps between the other cells in the phloem. 
The sieve cells are the conducting cells in the phloem. These are the cells which help in the transport of sugar. 
Thus, the correct answer is option D.