Question

Which of the following is without exception in Angiosperms : -

• A. Presence of vessels
• B. Double fertilisation
• C. Secondary growth
• D. Autotrophic nutrition.

Answer 1

The Correct Option is B

To determine which feature is without exception in angiosperms, let's evaluate each option:

1. Presence of vessels: While many angiosperms have vessels in their xylem, it is not a universal feature. For example, some angiosperms, like those in the Winteraceae family, lack vessels.
2. Double fertilisation: This is a defining characteristic of angiosperms. During double fertilisation, one sperm cell fertilises the egg to form the zygote, while the other sperm cell fuses with two polar nuclei to form the triploid endosperm. This process is unique and universal to angiosperms.
3. Secondary growth: Secondary growth, caused by vascular cambium and cork cambium, is not present in all angiosperms. Many herbaceous plants lack secondary growth entirely.
4. Autotrophic nutrition: Although most angiosperms are autotrophic, some are parasitic (e.g., parasitic plants like Cuscuta), indicating this is not a universal feature.

Therefore, the only characteristic that is without exception in angiosperms is double fertilisation. None of the other options are universal to all angiosperms. Hence, the correct answer is:

Correct Answer: Double fertilisation