The are collectively called the calyx.
sepals
petals
tepals
stamens

sepals

Explanation:

The flower is the reproductive organ of angiosperm plants. Flowers that have reproductive organs of both sexes, male and female, are called hermaphrodites (or monoecious).  Flowers that have reproductive organs of only one sex (male or female) are called dioecious.

A hermaphrodite flower is usually made up of four sets of modified leaves, the floral whorls. The whorls fit into a specialized branch called the floral receptacle. The four floral whorls are the chalice, consisting of the sepals, the corolla, consisting of the petals, the androceu, consisting of the stamens, and the gynoecium, consisting of the carpels.

x would be the most and the least would be y because there are more fruit   and seeds than flock z has insects