
Companion cells are associated with
A. Tracheids
B. Vessels
C. Sieve tubes of angiosperms
D. Sieve tubes of gymnosperms
Answer
410.4k+ views
Hint: Companion cells are living parenchymatous cells found inside the phloem of flowering plants. Each companion cell is generally in close association with a sieve element. Its function is to regulate the activity of the nearby sieve element and to help in loading of phloem sieve cells with sugars through active transport.
Complete solution:
Option A. Tracheids: Tracheids are enlarged cells found inside the xylem of vascular plants. They help to conduct water and mineral salts. Unlike vessel elements, tracheids do not possess perforation plates. The presence of tracheary elements differentiates vascular plants from nonvascular plants.
Option A is not correct.
Option B. Vessels: Vessels form the major part of the water transporting system. The building blocks of the vessel are known as vessel elements. Vessel elements are generally present in angiosperms (flowering plants) but are absent in majority of the gymnosperms
Option B is not correct.
Option C. Sieve tubes of angiosperms: Companion cells are characteristic components of phloem tissue, which are closely associated with the sieve tubes (sieve elements) in the angiosperms. Both are linked ontogenically, as they originate from the same mother cell. The sieve tubes and companion cells maintain close cytoplasmic connections via plasmodesmata.
Option C is correct.
Option D. Sieve tubes of gymnosperms: In gymnosperms, phloem lacks both sieve tubes and companion cells. Instead, they possess sieve cells for the conduction of food material. Sieve cells of gymnosperm lack a sieve layer, and in place of that have sieve pores that allow flow between adjacent cells.
Option D is not correct.
Hence, Option C is the correct answer.
Note:
Plasmodesmata (singular, plasmodesma) are minute channels that directly link the cytoplasm of neighbouring plant cells together, thus forming living bridges between cells. It perforates both the primary and secondary cell walls, and permits specific molecules to pass through one cell to another. Thus, it plays an important role in cellular communication.
Complete solution:
Option A. Tracheids: Tracheids are enlarged cells found inside the xylem of vascular plants. They help to conduct water and mineral salts. Unlike vessel elements, tracheids do not possess perforation plates. The presence of tracheary elements differentiates vascular plants from nonvascular plants.
Option A is not correct.
Option B. Vessels: Vessels form the major part of the water transporting system. The building blocks of the vessel are known as vessel elements. Vessel elements are generally present in angiosperms (flowering plants) but are absent in majority of the gymnosperms
Option B is not correct.
Option C. Sieve tubes of angiosperms: Companion cells are characteristic components of phloem tissue, which are closely associated with the sieve tubes (sieve elements) in the angiosperms. Both are linked ontogenically, as they originate from the same mother cell. The sieve tubes and companion cells maintain close cytoplasmic connections via plasmodesmata.
Option C is correct.
Option D. Sieve tubes of gymnosperms: In gymnosperms, phloem lacks both sieve tubes and companion cells. Instead, they possess sieve cells for the conduction of food material. Sieve cells of gymnosperm lack a sieve layer, and in place of that have sieve pores that allow flow between adjacent cells.
Option D is not correct.
Hence, Option C is the correct answer.
Note:
Plasmodesmata (singular, plasmodesma) are minute channels that directly link the cytoplasm of neighbouring plant cells together, thus forming living bridges between cells. It perforates both the primary and secondary cell walls, and permits specific molecules to pass through one cell to another. Thus, it plays an important role in cellular communication.
Recently Updated Pages
Glucose when reduced with HI and red Phosphorus gives class 11 chemistry CBSE

The highest possible oxidation states of Uranium and class 11 chemistry CBSE

Find the value of x if the mode of the following data class 11 maths CBSE

Which of the following can be used in the Friedel Crafts class 11 chemistry CBSE

A sphere of mass 40 kg is attracted by a second sphere class 11 physics CBSE

Statement I Reactivity of aluminium decreases when class 11 chemistry CBSE

Trending doubts
10 examples of friction in our daily life

One Metric ton is equal to kg A 10000 B 1000 C 100 class 11 physics CBSE

Difference Between Prokaryotic Cells and Eukaryotic Cells

State and prove Bernoullis theorem class 11 physics CBSE

What organs are located on the left side of your body class 11 biology CBSE

How many valence electrons does nitrogen have class 11 chemistry CBSE
