Which of the following remains unchanged for many millions of years?

Male gametes of cycads are

Assertion $(A)$: The scale leaves of $Araucaria$ are small and brown.
Reason $(R)$: The gametophyte stage of $Araucaria$ is long-lived and subterranean.
Which option is correct for Assertion $(A)$ and Reason $(R)$?

Pollination of pollen grains in $Pinus$ takes place at

Sieve tubes of $Pinus$ have sieve plates on

What types of leaves are found in gymnosperms?