Question

Diffuse porous woods are characteristics of
A. Alpine region
B. Cold winter regions
C. Temperate climate
D. Tropics

Answer 1

Hint: The wood can be classified into two types that is diffuse porous hardwood or ring porous hardwood and it depends on the climate conditions in which the tree is present. The difference in the hardwood of either type can be noticed by the change in the diameter of the vessels.

Complete answer:
The correct answer is (D).
Mostly ring-porous trees are found to be present in the north temperate areas of the world whereas most of the diffuse-porous trees are found in the tropical regions. As there is no visible difference present in between early and late wood of the tropical angiosperms, which may be caused by more or less uniform climate conditions, pores are said to be uniformly distributed throughout the ring and thus these are called diffuse porous wood plants.
Tropical regions and forests are present near the equator and are characterized by high rainfall and high intensity of solar radiations and thus plants growing in these regions show different characteristics.
Hardwood present in the plants classifies the plant species basically into two types that are ring-porous hardwood trees and diffuse-porous hardwood trees. In the ring-porous trees, the vessels present, at the start of the growing season are much larger than vessels which are present at the end of the season in the trees whereas in diffuse-porous hardwood trees, vessels present in the trees are of the same diameter throughout the season. No change is observed in the size of the vessels.
Vessels are found to be present only in the angiosperms and thus are a characteristic feature while gymnosperms like conifers or cycas do not contain any vessels. The larger size of the vessel if present provides an advantage to the plant as they permit more rapid conduction of the water.

Note: The presence of the vessels, their arrangement and change in their organisation and structure confers different properties and characteristic features to the plants. Also the climatic conditions in which the plants are growing induce different features in the plants which help them in better adaptation to the environment. Tropical plants are found to be very different from the plants growing in temperate or alpine or desert regions.