Data Were Collected from the Heterocysts of a Nitrogen-Fixing Cyanobacterium

question 10

Multiple Choice

Data were collected from the heterocysts of a nitrogen-fixing cyanobacterium inhabiting equatorial ponds. Study the graph and choose the most likely explanation for the shape of the curve.

• A) Enough oxygen (O₂) enters heterocysts during hours of peak photosynthesis to have a somewhat inhibitory effect on nitrogen fixation.
• B) Atmospheric nitrogen (N₂) levels increase at night because plants are no longer metabolizing this gas, so they are not absorbing this gas through their stomata.
• C) Heterocyst walls become less permeable to nitrogen (N₂) influx during darkness.
• D) The amount of fixed nitrogen that is dissolved in the pond water in which the cyanobacteria are growing peaks at the close of the photosynthetic day (1800 hours).

Comprehend how theme layouts affect the placement of text and content on slides.

Understand the role and importance of codecs in digital media file compression and internet transmission.

Learn how to use the Trim Video feature to control video playback in presentations.

Grasp how dragging or resizing operations affect slide objects.

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Definitions:

Subconscious

The part of the mind that is not currently in focal awareness but influences thoughts and behaviors.

Defense Mechanism

Psychological strategies unconsciously used to protect oneself from anxiety and internal conflict.

Displacement

in psychological terms, is transferring feelings or actions from the original object of those emotions to another target.

Projection

Attributing one’s own thoughts, feelings, or motives to another person.