Of the Entries in This List of Questions About the Milky

question 38

Multiple Choice

Of the entries in this list of questions about the Milky Way Galaxy, which ONE has been answered at the present time?

• A) Did the central black hole form first or did the Galaxy form first?
• B) Does the Galaxy have a central bar or not?
• C) What is dark matter?
• D) What is creating the positrons near the center of the Milky Way?

Explain the relationship between sieve elements and companion cells in plant phloem.

Differentiate between transpiration and translocation in plants.

Describe mutualistic relationships involving plant roots and their importance for ecosystem health.

Understand how plants can be used in environmental remediation, specifically through the example of poplar trees.

---

Definitions:

Market Demand

The sum of all the quantities of a good or service demanded per period by all the households buying in the market for that good or service.

Total Revenue

The total income a firm receives from selling its goods or services, calculated as the price per unit times the number of units sold.

Total Cost

Total Cost is the sum of all expenses incurred in the production of goods or services, including both fixed and variable costs.

Marginal Revenue Curve

A graph illustrating the additional revenue a firm gains when it sells one additional unit of a product.