What is an artificial (synthetic) seed?

• Artificial or synthetic seeds are seed-like units created by encapsulating plant propagules—most classically somatic embryos—in a hydrogel such as sodium alginate or other gelatinous matrices.​

• These encapsulated units behave like true seeds: they can be handled, stored, sown, and germinated into complete plants, offering a way to mass‑propagate elite clones or plants with poor natural seed set.​

Explanation of each option

1. Microcalli

• Microcalli are small pieces of undifferentiated callus; while cell aggregates can sometimes be encapsulated as synthetic seeds, the classic and exam‑standard definition of artificial seed refers specifically to encapsulated somatic embryos that structurally resemble zygotic embryos.​

• Therefore, microcalli are not the best answer here.

2. Somatic embryos – CORRECT

• Somatic embryos arise from somatic (non‑zygotic) cells via somatic embryogenesis and pass through embryo stages similar to zygotic embryos.​

• Encapsulating these somatic embryos in a gelatinous hydrogel matrix forms artificial seeds, which can then germinate into whole plants under in vitro or ex vitro conditions.​

3. Root tips

• Root tips are meristematic but lack the bipolar embryo organization that seeds or somatic embryos have; they are usually propagated through microcuttings or rooting media rather than encapsulated as “artificial seeds.”​

• While some advanced protocols may encapsulate various meristems, root tips are not the standard answer for this definition-based question.

4. Shoot tips

• Shoot tips and shoot buds can be encapsulated and are sometimes included under a broad definition of synthetic seeds, but the classical textbook definition—and the one most exam questions target—uses somatic embryos as the primary propagule.​

• Hence, compared with somatic embryos, shoot tips are a less precise match to the phrase “is referred as artificial seed” in a single‑best MCQ.

SEO‑oriented introduction (for article use)

In plant tissue culture, an artificial seed is typically created by encasing somatic embryos in a gelatinous matrix such as sodium alginate, producing seed‑like units that can be stored, handled and sown like natural seeds. This encapsulation of somatic embryos—not microcalli, root tips, or shoot tips—is the key feature that defines classical artificial seed technology in micropropagation and plant biotechnology.​