These structures are mainly classified into determinate or indeterminate types depending on whether or not they maintain active meristems in zone I (“one”). For 10 points each:
[10m] Name these cylindrical structures largely used by legumes to harbor nitrogen-fixing Rhizobium bacteria. These structures often form around root curls and produce leghemoglobin to regulate oxygen concentrations.
ANSWER: root nodules [accept nitrogen-fixing nodules]
[10h] These starch-filled organelles begin to disappear after nodule cells are infected with Rhizobium bacteria. Statoliths are a type of this double-membrane organelle that can sense the direction of gravity in stem and root tips.
ANSWER: amyloplasts [prompt on plastids or plasts; prompt on leucoplasts; reject “chloroplasts” or “chromoplasts”]
[10e] Plant responses to Rhizobium and arbuscular mycorrhizal organisms from this kingdom share a common symbiosis signaling pathway. This kingdom includes ascomycetes that can extend their hyphae between plant cells.
ANSWER: fungi [or fungus]
<AL, Biology>