In one sentence, explain how it is possible for genetically identical plant cells to become quite ...

Answer to q. 1

In the process of differential gene expression, genetically identical cells can have different genes being
activated while others are inactivated, resulting in those cells becoming structurally and functionally
different.

Answer to q. 2

Primary growth refers to growth in stem and root length. This vertical growth occurs only at
the root and shoot tips, specifically at the root and shoot apical meristems. Primary growth
results in the formation of primary tissues, such as primary xylem, primary phloem,
parenchyma, collenchyma, and sclerenchyma. Secondary growth refers to lateral growth; i.e.,
secondary growth results in an increase in the girth of the plant. Secondary growth results
from the activity of lateral meristems, which in term produce secondary tissues: the vascular
cambium produces secondary xylem and secondary phloem, and the cork cambium produces
cork parenchyma and cork cells. These last three tissues comprise the periderm which replaces
the epidermis in woody plants.

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