Question

1 place a few live flatworms in a petri - dish containing pond water, and use the dissecting microscope to observe paths of the animals. are the paths straight or meandering? explain why.
2 next, using a toothpick, place a very small piece of hard - boiled egg yolk at the far side of the petri dish away from the flatworms.
3 observe their responses for the next several minutes. does the path of the flatworms change after adding the egg?
4 if not, try gently swirling the water or moving the egg yolk closer to the animals.

Explanation:

1. Flatworms may move in meandering paths as they explore their environment randomly in search of food or suitable conditions without a specific straight - line goal initially. When a food source (hard - boiled egg yolk) is introduced, their movement behavior may change. If they detect the food, they may start moving towards it in a more directed manner. If they don't detect it immediately, their paths may remain meandering. Swirling the water or moving the egg yolk closer can help them detect the food source, potentially changing their movement path to a more direct one towards the food.
2. If the flatworms detect the egg yolk as a food source, their path is likely to change to move towards it. If they don't detect it, their path may remain the same as before the egg yolk was added.
3. As above, if they sense the food, the path will change to a more directed one towards the food, otherwise it may remain meandering.
4. These actions increase the likelihood of the flatworms detecting the food source, which can cause their movement path to change from a random, meandering one to a more direct path towards the food.

Answer:

1. Initially, the paths are likely meandering as flatworms randomly search for resources. Reason: They move without a specific target initially.
2. If they detect the egg yolk as food, the path may change to a more directed one towards the yolk. If not, it may remain the same.
3. If they sense the food, the path changes to a directed one towards the food; if not, it remains meandering.
4. These actions may cause the flatworms to detect the food, changing their path from meandering to directed towards the food.