Final answer:
The female gamete of the tobacco plant, like the male gamete, has 24 chromosomes. Upon fertilization, the zygote formed will have 48 chromosomes, which is the sum of the chromosome counts from both gametes, resulting in the correct answer being option A.
Step-by-step explanation:
In sexual reproduction, both male and female gametes are haploid, which means they each contain half the number of chromosomes that are found in the somatic (body) cells of an organism. In the case of the tobacco plant, if the male gametes have 24 chromosomes, the female gametes would also have the same number, 24 chromosomes, since gametes have a one-to-one chromosome ratio.
When a male and a female gamete fuse during fertilization, they form a zygote. The zygote will contain the full diploid complement of chromosomes, which is the sum of the chromosomes from both gametes. Therefore, if each gamete contributes 24 chromosomes, the resulting zygote will have a total of 48 chromosomes.
The correct option, given the context of the question, is: A. The number of chromosomes in the female gamete is 24, the number of chromosomes in the zygote is 48.