Answer:
If a species has a number of chromosomes 2n = 18, then its somatic cells have 16 autosomes.
Step-by-step explanation:
Somatic cells are diploid, that is, they have the complete chromosomal charge, and it is represented as 2n. In organisms with sexual reproduction the chromosomes are divided into autosomes and sex chromosomes, which are 2.
If a species has a number 2n = 18, it means that its somatic cells have 18 chromosomes, of which 16 are autosomes and 2 are sex chromosomes. Autosomes contain the structural and functional characteristics of an individual, while the sex chromosomes determine sex.