67. In most angiosperms, flowers have a perianth that consists of whorls of organs. Select the statement that is INCORRECT about the floral organs in angiosperms.
    (1) All petals are not homologous
    (2) If there is only one whorl of organs, these structures are referred to as tepals
    (3) Sepals tend to be initiated almost simultaneously and never in a spiral sequence.
    (4) Both sepals and petals can act as protective organs for inner floral organs and also as organs to attract pollinators

Introduction

Flowers of angiosperms consist of specialized organs arranged in concentric whorls comprising sepals, petals, stamens, and carpels. The pattern of development and functional roles of these organs are diverse but follow certain common principles. Clarifying their developmental sequences and distinctions sheds light on floral morphology and evolution.

Review of Floral Organ Statements

• Petal Homology: Petals are not always homologous among all angiosperms due to evolutionary divergence. Different lineages may possess petals arising from different organs or structures.​

• Tepals: In flowers with a single whorl of perianth organs that are undifferentiated or indistinguishable as sepals or petals, these organs are called tepals, common in monocots like lilies.​

• Sepal Initiation: Contrary to the statement, sepals generally initiate in a spiral sequence, a common phyllotactic pattern in many angiosperms, rather than all at once synchronously. This spiral initiation is critical for proper floral organ spacing.​

• Protective and Attractant Roles: Both sepals and petals provide protective roles for inner organs during bud development and also help attract pollinators via pigmentation and morphology.​

Detailed Explanation of Sepal Initiation

• Sepals usually initiate sequentially in a spiral pattern from the meristem periphery allowing optimal positioning.

• The claim that sepals “never” initiate in a spiral sequence is not accurate for most angiosperms, where spiral initiation is well-documented.​

Summary Table: Floral Organ Features

Conclusion

The consensus in floral developmental biology is that sepals in most angiosperms initiate in a spiral sequence rather than simultaneously, making statement (3) incorrect. All other statements about petal homology, tepals, and dual roles of sepals and petals are accurate.