Question

Xenia and metaxenia effects are shown by
A. Gymnosperms
B. Angiosperms
C. Bryophytes and pteridophytes
D. All of the above

Answer 1

Hint: Plants are the eukaryotic multicellular organisms. Plants are the autotrophs that means they can make their food by own with the help of the process of photosynthesis (it is a process in which plants make their food with the help of inorganic materials like carbon dioxide, water, sunlight and chlorophyll).

Complete Answer:
Xenia effect: Xenia effects in plants is the effect of pollen grains (male gametes) on seeds and fruit (female part )of the fertilized plant.
- The term Xenia was coined in 1881 by the botanist Wilhelm Olbers Focke .
- Xenia effect is the effect on maternal tissues including the seed coat and pericarp.

Metaxenia effect: Metaxenia is the effect of pollen grain (male gametes) on the fruit shape and other characteristics of the fruit.
- It is the effect of pollen on the developing ,maternal tissues of a seed or fruit outside the embryo and endosperm.
- This effect is caused due to the hormones produced by the embryo and endosperm after double fertilization (fertilization in which one of the male gamete fuses with the egg cell and one male gamete fuses with the polar central nuclei).
- As xenia and metaxenia both are the effects of pollen grains on the seeds or fruit.

Angiosperms are the only plants that bear flowers, that’s why they are also called as the flowering plants. So only angiosperms show the xenia and metaxenia effects.

Hence, option B is the correct option for this question.

Note: Xenia and metaxenia effect may be used to identify the best pollenizer to decrease the fruit development period and increase the yield.