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2021-05-14

Which tissue is responsible for secondary growth in stems?

Which tissue is responsible for secondary growth in stems?

lateral meristems

What are the secondary function of a stem?

1. Provides support and bears leaves, flowers and fruits. 2. It transports water and mineral nutrients to the other parts from the root.

What is secondary growth in dicot stem?

In vascular bundles of a dicot stem, the cambium is present in between the xylem and phloem. It is known as intrafascicular cambium. Both the intra-fascicular and inter-fascicular cambium unite together to form a complete ring called the cambium ring. The activity of the cambium ring gives rise to secondary growth.

Which Monocot shows secondary growth?

Normally secondary growth takes place in roots and stem of dicotyledons and gymnosperms. Due to lack of cambium in monocotyledons, secondary growth is absent. But exceptionally, secondary growth takes place in some monocotyledons, such as palm, Yucca, Dracaena etc.

Can monocots have secondary growth?

In general, monocots do not undergo secondary growth. If they do increase in girth (like palm trees and yucca plants), it does not result in the development of a secondary xylem and phloem, since monocots don’t have vascular cambium. An increase in girth without secondary growth is referred to as anomalous thickening.

Which shows secondary growth?

In many vascular plants, secondary growth is the result of the activity of the two lateral meristems, the cork cambium and vascular cambium. Arising from lateral meristems, secondary growth increases the width of the plant root or stem, rather than its length. In the case of the cork oak it will yield harvestable cork.

Which meristem is responsible for secondary growth?

Lateral meristems

What is difference between primary and secondary growth?

The increase in length of the shoot and the root is referred to as primary growth. It is the result of cell division in the shoot apical meristem. Secondary growth is characterized by an increase in thickness or girth of the plant.

Which is the best example of anomalous secondary growth?

Bougainvillea is a member of the Nyctaginaceae and is an example of a dicotyledonous stem which displays anomalous secondary growth. In this TS, near the centre of the stem, you will see some primary vascular bundles embedded in lignified pith parenchyma.

Why is there no secondary growth in monocots?

Secondary growth is the growth in thickness due to the formation of secondary tissues by lateral meristems. These tissues are formed by meristems, vascular cambium and cork cambium respectively. Secondary growth does not occur in monocots because monocots do not possess vascular cambium in between the vascular bundles.

What do you mean by anomalous secondary growth?

Abstract. “Anomalous secondary growth” is the term under which have been grouped cambial conformations, cambial products, and cambial numbers which differ from the most common “normal” condition, namely, a single cylindrical cambium that produces phloem externally and xylem internally.

Which of the following is involved in secondary thickening in plants?

The thickening of the stem that occurs in secondary growth is due to the formation of secondary phloem and secondary xylem by the vascular cambium, plus the action of cork cambium, which forms the tough outermost layer of the stem. The cells of the secondary xylem contain lignin, which provides hardiness and strength.

Which one is correct about the secondary growth?

Secondary growth results in increase in girth or diameter of the stem by formation of secondary tissue by the activity of lateral meristem. So for study of secondary growth, teak (angiosperm) and pine (gymnosperm) are best suited. In wheat, fern and sugarcane there is no secondary growth. So, option C is correct.

Does secondary growth occur in gymnosperms?

Secondary growth is a feature of gymnosperms and most dicot plants (dicot woody plants). Stem transformation: from primary to secondary growth by the activity of the vascular cambium meristem, which results from the procambium (fascicular cambium) and interfascicular meristems. Secondary growth.

Why cambium is called lateral meristem?

Cambium is considered to be a lateral meristem because it is present along the lateral sides of stem and roots. For example, interstellar cambium ring formed by intrafasicular and interfascicular cambium.

How is secondary meristem formed?

Secondary Meristem: Secondary meristems are the meristematic tissue arises from the permanent tissues. Secondary meristems are usually lateral meristems and are responsible for the increase in thickness of the plant. Example: vascular cambium and cork cambium (phellogen).

Which is an example of a secondary meristem?

Cork cambium is an example of secondary meristem.

What is the other name of secondary meristem?

There are two types of secondary meristems, these are also called the lateral meristems because they surround the established stem of a plant and cause it to grow laterally (i.e., larger in diameter). Vascular cambium, which produces secondary xylem and secondary phloem.

What is the difference between primary and secondary meristem?

The main difference between primary and secondary meristem is that primary meristem is derived from the promeristem whereas secondary meristem is derived from permanent tissues. Furthermore, primary meristem is involved in the primary growth while secondary meristem is involved in secondary growth.

Which one is not a lateral meristem?

Thus the correct answer is Option (A) – Intercalary meristem.

What is the meaning of secondary meristem?

: a meristem that develops from cells that have differentiated and functioned as part of a mature tissue system and then become meristematic again — compare primary meristem.

Which cell shows the presence of pits?

tracheids

What is the difference between Plasmodesmata and pits?

The key difference between pits and plasmodesmata is that pits are the thin regions of the plant cell wall that facilitate communication and exchange of substances with neighbouring cells while plasmodesmata are microscopic intercellular bridges that connect the cytoplasm of neighbouring cells with each other.

What is the function of pits in plant cells?

Minute openings (pits) in the secondary cell wall of water conducting elements play an important role in water transport in living plants. They allow the flow of water and nutrients from one element to another, linking water uptake in roots with transpiration in leaves.

Which is absent in the area of pits?

So, the correct answer is ‘Secondary wall’.

What is the meaning of pits?

1 : a cavity or hole in the ground usually made by digging a gravel pit. 2 : an area set off from and often sunken below surrounding areas a barbecue pit a theater’s orchestra pit. 3 : a small hole or dent on a surface.

What is the bordered pits function?

The functionality of the xylem network depends to a large degree on bordered pits that connect adjacent conduits and the finely porous pit membranes, which prevent the movement of gas and pathogens between conduits (Zimmermann & Brown, 1971). Thus bordered pits act as safety valves in the hydraulic system of plants.