The Two Principal Types of Conducting Cells in the Xylem

question 22

Multiple Choice

The two principal types of conducting cells in the xylem are _________ and ________.

• A)tracheids;vessel elements
• B)sieve tubes;companion cells
• C)sieve cells;sieve tube members
• D)guard cells;tracheids
• E)protoderm cells;pericycle cells

---

Definitions:

Normal Time

The amount of time typically required to complete a task or process under standard conditions, often used in planning and scheduling.

Standard Time

The amount of time allowed for the completion of a job or task based on average speed under normal conditions.

Variable Allowance

An adjustment in cost or time estimates to accommodate changes or variations that may occur in project planning or execution.

Allowance Factor

A factor or percentage added to an estimate to account for uncertain conditions, providing a margin for error or unforeseen costs.