Week 3 - sample lab exam question

WEEK 3 - SAMPLE LAB EXAM QUESTION

QUESTION:

Some botanists view Psilotum nudum as a living fossil, very similar in structure to the earliest vascular plants.

Figure A shows the vascular cylinder of the Psilotum nudumsporophyte. B is a preserved specimen of the sporophyte of Psilotum nudum, showing the dichotomously branched stem with sporangia.

Name three features that the sporophyte of Psilotum nudum is thought to share with the first vascular plants.
ANSWER:

Any three of:
1. Simple, upright stem with dichotomous branching.
2. No true roots (lack vascular tissues); rhizoids for anchorage.
3. No true leaves (lack vascular tissues)
4. Single, central vascular cylinder with xylem surrounded by phloem.
5. Sporangia on stems.

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