Final answer:
Tobacco plant pollen cells have 24 chromosomes, which is half of the diploid number (48 chromosomes) found in somatic cells.
Step-by-step explanation:
The number of chromosomes in tobacco plant pollen cells can be understood by knowing the basic principles of plant reproduction and life cycle. Tobacco plants are diploid organisms, which means they have two sets of chromosomes, one set inherited from each parent. In their reproductive process, they produce haploid gametes through meiosis, which means each pollen grain (male gamete) would have half of the diploid number. Since tobacco plants have 48 chromosomes in their diploid cells, their pollen cells will have 24 chromosomes.