Use the Following Information When Answering the Corresponding Questions)

question 26

Multiple Choice

Use the following information when answering the corresponding questions) .
Suzanne Simard and colleagues knew that the same mycorrhizal fungal species could colonize multiple types of trees. They w if the same fungal individual would colonize different trees, forming an underground network that potentially could transpor and nutrients from one tree to another S. Simard et al. 1997. Net transfer of carbon between mycorrhizal tree species in the fi Nature 388:579- 82) . Figure 29.2 illustrates the team's experimental setup. Pots containing seedlings of three different tree species were set up and grown under natural conditions for three years; two of the three species formed ectomycorrhizae Douglas fir, birch) and the other cedar) formed arbuscular mycorrhizae. For the experiment, the researchers placed airtight bags over the Douglas fir and birch seedlings; into each bag, they injected either carbon dioxide made from carbon- 13 or carbon- 14 ¹³CO₂ and ¹⁴CO₂, isotopes of carbon) . As the seedlings photosynthesized, the radioactive carbon dioxide was converted into radioactively labelled sugars that could be tracked and measured by the researchers.
Figure 29.2
-Refer to Figure 29.2. Which of the following results would support Simard et al.'s 1997) hypothesis that fungi can move carbon from one plant to another? Hypothesis: Sugars made by one plant during photosynthesis can travel through a mycorrhizal fungus and be incorporated into the tissues of another plant.

• A) Either carbon- 13 or carbon- 14 is found in the cedar seedling's tissues.
• B) Carbon- 14 is found in the birch seedling's tissues and carbon- 13 in the Douglas fir.
• C) Either carbon- 13 or carbon- 14 is found in the fungal tissues.
• D) Carbon- 14 is found in the Douglas fir seedling's tissues and carbon- 13 in the birch.

---

Definitions:

Symbolic Thinking

The process of using symbols, such as words or images, to represent objects, actions, or ideas not immediately present.

Limbic System

A complex system of nerves and networks in the brain, involving several areas near the edge of the cortex concerned with instinct and mood. It controls the basic emotions (fear, pleasure, anger) and drives (hunger, sex, dominance, care of offspring).

Reactivity

The state or capacity of being reactive or the degree to which a thing is reactive.

Orphanages

Residential institutions dedicated to the care of children whose parents are deceased or otherwise unable or unwilling to care for them.