Biology 1st Edition by Jerome Krueger, Kendra Hill, Robert Noyd

تمرين 17

Geckos are a group of 850 species of lizards (reptiles) that have two amazing adaptations. First, geckos can rapidly run up walls and along ceilings, leaves, and other horizontal surfaces. The secret lies in the structure of their toe pads, which are covered with millions of microscopic branched elastic hairs ( Fig. a ). In order to run, the toe pads must be able to attach and detach within milliseconds and not stick to each other.
a. Predict which kind of tissue and biological macromolecule -carbohydrates, lipids, or proteins-compose the hairs on the bottom of the gecko toe pad.
b. Briefly describe how biologists would study these remarkable foot hairs at the molecular, cellular, tissue, organ system, and organism levels of the hierarchy to understand this amazing adaptation.
Second, when confronted or attacked by a predator, a gecko can actually break off its tail ( Fig.b ). The detached tail can wiggle and move to distract the predator just long enough for the gecko to make a quick getaway. The tailless lizard will grow a new tail over a period of weeks.
c. Predict how each of the four types of tissues functions in this defense adaptation. What tissues compose the detached tail so that it can move? Explain.
Figure Gecko adaptations.