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 type of plants have little or no secondary growth, and the correct answer is 'Grasses'. Let's delve into more details to understand why grasses fit this criteria:

1. Understanding Secondary Growth:
   Secondary growth refers to the increase in thickness or girth of the plant, and it is primarily the result of the activity of the vascular cambium and cork cambium. This type of growth is characteristic of dicots and gymnosperms.
2. Characteristics of Grasses:
   Grasses are monocots, which typically do not undergo secondary growth. Monocots lack the vascular cambium, which is the tissue responsible for the lateral growth in plants. This is why grasses maintain a relatively uniform thickness throughout their lifespan.
3. Comparison with Other Plant Types:
   • Conifers: These are gymnosperms, which do show secondary growth due to the presence of vascular cambium. Examples include pine trees.
   • Deciduous Angiosperms: These are dicots, which generally have secondary growth, leading to thicker stems and trunks.
   • Cycads: Cycads are gymnosperms, and like conifers, they have secondary growth.
4. Conclusion:
   Given these explanations, grasses are the only group among the options provided that have little or no secondary growth. This difference is primarily due to their classification as monocots, which lack the necessary cambium for secondary thickening.