Yeast multiplies by which of the following methods?

The chapter states: "Yeast, on the other hand, can put out small buds that separate and grow further, as we saw in Activity 7.1." In budding, a small outgrowth (bud) forms on the parent yeast cell due to repeated cell division at one site, which then detaches to become a new independent individual — this is exactly what is observed when yeast is grown in sugar solution (Activity 7.1). Hence (D) is correct.

Why the distractors fail: (A) Fragmentation is the mode used by simple multicellular organisms like Spirogyra, which breaks into pieces upon maturation — yeast is unicellular and does not fragment this way. (B) Binary fission (splitting into two equal halves) is characteristic of bacteria, protozoa and Amoeba, not yeast. (C) Multiple fission (splitting into many daughter cells simultaneously) is seen in Plasmodium, the malarial parasite, not yeast.