Some Clues to Describing and Understanding Organisms
Here are some clues to describing and understanding organisms to help focus your biodiversity research, in these three places:
- in the classroom (as you form your questions and build hypotheses)
- in the field (as you observe and collect data),
- in the "lab" (back at school, as you analyze data, create graphic presentations, and review hypotheses)
(Remember: Some clues can be seen only close-up in the lab, but with practice, you'll see many in the field.)
After noting a characteristic of the organism, always ask yourself, "Why might it be this way? What might this clue indicate?"
For all organisms, consider microhabitat:
Does the organism always occur in the same "zone"?
- moisture level
- soil type
- Does it occur in clumps, or is it on its own, far from others of the same species?
- If in clumps, do they seem randomly distributed, or do you see a pattern?
- Is it always associated with the same plant species, or do you find it with a variety of other plants?
How does the plant hold itself up when it doesn't have a skeleton?
- Is it woody or herbaceous (non-woody)?
- If it's woody, is there one main trunk (trees), or are there several (shrubs)?
- Does the plant stand up by itself, sprawl along the ground, or use something else for support (vines)?
Leaf Type: Does the leaf look like:
- a regular broad-leaf, with a little stem (petiole) and a flat, wide blade?
- a long strap?
- a needle or a tiny scale?
- If the leaf has a petiole and blade, what shape is the blade?
Leaf Arrangement: How are the leaves arranged on a stem?
- Are there two leaves attached to the same part of the stem (opposite)?
- Are there more than two leaves attached to the same part of the stem (whorled)?
- Do the leaves attach to the stem in a zigzag or spiral pattern (alternate)?
Reproduction: How does the plant produce offspring?
- Do you see flowers on the plant?
- Where are the male and female parts of the flower?
- How do you suppose the male parts meet the female parts?
- Do you see fruits or cones on the plant?
- If so, can you find the seeds?
- How do you think seeds get around to new locations?
Plant Defense: How do you suppose plants protect themselves from predators when they can't run away?
- Does the plant have any spines?
- Do the leaves look very hairy?
- Are certain parts of the plant very tough and hard to digest?
- Does the plant have a distinct smell?
- Do you see anything eating the plant, or signs that something has been eating it?
Behavior: Look for clues to how and where it earns its living, for example:
- Is constantly visiting flowers?
- Does it run around in the open?
- Is it found only in the dark, under stones or logs?
- Does it lie waiting in some kind of trap?
Location: Look for clues to the kind of places it prefers.
- If on vegetation, is it chewing leaves? Piercing? Sucking?
- Is it always on the same type of plant?
- Does it occur in large numbers or on its own?
Occupation: What's it up to? For example:
- Is it involved with another arthropod?
- Is it eating? Is it being eaten?
- Is it just "hanging out"?
- Is it mating? Is it laying eggs?
- Is it tending to eggs or larvae?
- Is it carrying eggs or larvae?
- Is it fighting? Showing off ("displaying")?
Morphology: How's it built?
- Mouthparts: How do you think it might feed? Might it suck? Pierce? Bite? Does it have poison fangs?
- Legs and other appendages: How long are they? How long are legs compared to other appendages? (For example, does it have huge rear legs like a grasshopper? Or a long "stinger" like an ichneumonid wasp?)
- Eyes: How big are they? How complicated? (For example, does it have huge compound eyes like a dragonfly? Or tiny, simple eyes like many spiders?)
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