"You discover a new species of snail, Biologica terificia, and find that its haploid number is 4 (n = 4). The somatic cells of Biologica terificia are diploid. How many chromosomes are in a somatic cell of the snail in G1 phase?

8 chromosomes

Explanation:

Diploid state is when an organism have two set of chromosomes (2n) i.e. combination of two haploid (n) gametes containing one set of chromosome each. Sexually reproducing organisms whose somatic or body cells are diploid (2n) undergo meiosis to produce gametes or sex cells with haploid number (n).

Therefore, in the newly discovered Biologica terificia species of snail, if the haploid state (n) of their gametes is 4, then their diploid (2n) somatic cells must be 4 × 2 = 8.

The question specifies the chromosomal number at the G1 phase of Interphase. At this stage, the cell is preparing to undergo division by increasing in size and duplicating its organnelles but not yet its genetic material which is not until the next phase called S-phase. Hence, the chromosome number of somatic cells remain 8 at the G1 phase.

First Hand source

Explanation:

because they have a direct account of the event, and they don't have their facts mixed.