Question

Plants having little or no secondary growth are

• A. Grasses
• B. Conifers
• C. Deciduous angiosperms
• D. Cycads

Answer 1

The Correct Option is A

The question asks which plants have little or no secondary growth. Let's explore what secondary growth is and analyze the options provided.

Understanding Secondary Growth:

• Secondary growth refers to the increase in thickness or girth of the plant, primarily due to the activity of the vascular cambium and cork cambium.
• This type of growth is typically observed in woody plants, such as trees and shrubs.
• Secondary growth results in the formation of wood and bark, features predominantly seen in dicots and gymnosperms.

Analyzing the Options:

• Grasses: Grasses are monocots. Monocots generally lack secondary growth because they do not have a vascular cambium. This means grasses remain herbaceous with primary growth only. Therefore, grasses fit the description of plants having little or no secondary growth.
• Conifers: Conifers are gymnosperms that exhibit secondary growth. They produce wood and have a thickened trunk due to the presence of vascular cambium. Hence, conifers do experience secondary growth.
• Deciduous Angiosperms: These are typically dicots, which do undergo secondary growth facilitated by vascular and cork cambium, producing wood and bark.
• Cycads: Cycads, like conifers, are gymnosperms and do possess secondary growth as they develop a woody structure.

From this analysis, it is clear that Grasses are the plants with little or no secondary growth because they do not have the structural cambium necessary for increasing wood girth.

Conclusion: The correct answer is Grasses. They are monocots and show only primary growth without the involvement of secondary tissue layers.