2. specialized cellular modifications- plant cells have chloroplasts and large central vacuole.
Explanation:
<u>Case I
</u>
Evolutionary unity is a concept which explains that all the organisms possess some common structure or universal structure or molecules.
The best characterized evolutionary molecule is DNA molecule which took the role of genetic material in past and is passed on to the daughter cells and still is made up of the same components which are a five-carbon sugar, four types of nitrogenous bases and a phosphate group. This DNA molecule is present in almost every organism except for a few viruses.
<u>Case II
</u>
The specialization of the cellular components depends on the function a cell has to perform which became established in the population. The plant cells depended on the sunlight to prepare food for themselves which was done by the chloroplast organelle which is absent in the animal kingdom.
Sexual reproduction happens when there is the involvement of two parents to give rise to the offsprings.
For the production of offsprings, each of the parents produces a haploid gamete and it is by the fusion of these two haploid gametes that a diploid organism is produced.
In the given situation, there are 19 chromosomes present in the haploid gametes this means that a diploid individual will have 2X19 = 38 chromosomes.
Now the underground stem cells are not gametes but somatic cells and the somatic cells are diploid and hence, they will have 38 chromosomes.