[Campbell Biology P.662] Based on Figure 28.28, which statement correctly describes a stage ... | Practice Question

Based on Figure 28.28, which statement correctly describes a stage in the life cycle of Dictyostelium?

  • A: Solitary amoebas in the feeding stage are diploid (2n) and primarily reproduce sexually.
  • B: Fertilization involves two haploid amoebas fusing to form a diploid zygote, which then undergoes meiosis.
  • C: The slug-like aggregate is composed of diploid cells (2n) that migrate to find new food sources.
  • D: Spores are released from the stalk, and these spores are diploid (2n) and immediately begin feeding.

Explanation

Figure 28.28 clearly shows that fertilization step 2 involves two haploid amoebas fusing to form a diploid zygote 2n . Following this, the giant cell derived from the zygote undergoes meiosis, leading to the release of haploid amoebas. Solitary amoebas and the slug-like aggregate are shown as haploid n by the blue arrow, and spores are also haploid. Spores only begin feeding under favorable conditions after emerging from their coats.