Anabaena Is a Cyanobacterium with Two Types of Cells

question 23

Multiple Choice

Anabaena is a cyanobacterium with two types of cells. One type of cell can carry out photosynthesis and the other type can carry out nitrogen fixation. However, the oxygen produced by photosynthesis inhibits the enzymes for nitrogen fixation. Which structural characteristic allows the nitrogen-fixing cells to continue to function?

• A) modified plasma membranes that are impermeable to both oxygen and nitrogen
• B) cell walls that are impermeable to both oxygen and nitrogen
• C) specialized cells called heterocysts, which have cell walls that restrict the entry of oxygen
• D) plasma membranes that are impermeable to nitrogen

---

Definitions:

Resize Controls

User interface elements that allow the adjustment of the size of windows or other components in software applications.

Detail Section

A portion of a report or document where individual records or items of information are displayed in detail.

Bottom Margin

The space at the bottom of a page in a document that separates the text from the page edge, ensuring content is not obscured during printing or viewing.

Report Layout View

A feature in database and reporting software that allows users to visually design and modify the layout of reports.