Some desert plants have very small leaves whereas some others have only spines. How does this benefit the plants?

Some features of plant leaves are

Name some other steel plants of India other than integrated steel plants.

The plant having small seeds and feather like structures are

Which of the following statement/s is/ are WRONG ? I. Mammals from colder climates generally have shorter ears and limbs to minimise heat loss. II. The UV component of the spectrum is harmful to many organisms. III. The tiger census in our national parks and tiger reserves is often based on actual headcounts. IV. Some desert plants like Opuntia,have no leaves - they are reduced to spines. V. In brood parasitism , the parasitic bird lays its eggs in the nest of its host and does not allow the nest incubate them.

Plants adapted to deserts have

Why some plants of cycas produce seeds but not others ?