PIMSO 2022 - Science - Grade 10 - National Round Question 6

Question 6

The following graph shows the phylogenetic tree of representative genomic sequences of SARS-CoV-2 variants worldwide. Which of the following statements is not true regarding the variants, as demonstrated by the tree?

Question illustration

Historical scope: interpret the pictured 2022-era tree; select the ancestry statement contradicted by its topology. Sampling counts are not a prevalence survey.

The Omicron variant evolved from the Delta variant.
The Omicron variant has currently two subvariants.
The Omicron variant is currently the prevalent strain worldwide.
The Delta variant was the most prevalent strain during 2021.
The Delta variant still exists among the population.