Final answer:
A sperm cell containing 8 chromosomes indicates that the organism's regular body cells would have 16 chromosomes, because body cells are diploid and have twice the number of chromosomes as haploid gametes like sperm.
Step-by-step explanation:
If a sperm cell contains 8 chromosomes, it comes from an animal whose regular body cells have 16 chromosomes. This is because sperm cells are haploid, meaning they contain only one set of chromosomes, which is half the number in the diploid body cells.
In humans and many other organisms, gametes (sperm and egg cells) are haploid (1n) containing one set of chromosomes. Regular body cells, also known as somatic cells, are diploid (2n) and contain two sets of chromosomes, one from each parent.
Since human gametes have 23 chromosomes, resulting from the halving of the diploid number which is 46, we can apply this logic to the organism in question. Therefore, if a sperm cell of this organism has 8 chromosomes, the regular body cells must have twice that amount, or 16 chromosomes, due to the diploid nature of somatic cells.