Plants are stationary and need to be upright.
Explanation
The fundamental anatomical differences between plants and animals are largely dictated by their mode of life. Plants are stationary (sessile) organisms that must withstand environmental forces while remaining fixed, whereas animals are mobile.Detailed Analysis:
- Plants have a higher metabolic rate than animals. is incorrect: Plants generally have a lower metabolic rate than animals. Animals consume significant energy for locomotion and complex physiological processes, requiring living, metabolically active tissues. Plants, having lower energy demands, can sustain a larger proportion of dead tissues.
- Plants are stationary and need to be upright. is correct: Because plants are stationary, they require rigid structural support to stand upright against gravity and endure wind or physical stress. Dead supportive tissues, such as sclerenchyma and xylem, provide this necessary mechanical strength. Crucially, dead tissues provide structural integrity without consuming energy for maintenance, which is evolutionarily efficient for a stationary organism.
- Dead tissues conduct water more efficiently than living tissues. is incorrect: While dead xylem vessels are efficient at conducting water, the primary reason for the overall high proportion of dead tissue (including bark and wood) is mechanical support. Animals also require transport systems but use flexible, living tissues (like blood vessels) to accommodate movement.
- Plants do not have a nervous system to control movement. is incorrect: The absence of a nervous system is a physiological characteristic of plants but is not the reason for the prevalence of dead supportive tissues.
Key Takeaway: Plants possess a large proportion of dead supportive tissues primarily to ensure mechanical strength and upright posture required by their stationary habit, while minimizing metabolic energy expenditure.