Trace the pathway (including diagrams and labels) between the brain and one of the main sensory organs in the head.

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.

i believe the answer is snake.

anthropod traits:

a well-developed collarbone

rotating shoulder joints

partially rotating elbow joints

opposable thumb

similar dental formula

the answer is: the „power stroke“ step.

muscle contraction can be divided into a few steps:

1. the release of ach (acetylcholine) in the synaptic cleft, binding of ach for its receptor and consequently opening of the ca channels.

2. the release of ca, binding of ca for the troponin

3. troponin shifting the tropomyosin, which was blocking the active site on the actin

4. myosin heads attaching to actin by breaking down atp to adp+ pi

5.   formation of the ‘cross-bridge’ on the active site of the actin filament by myosin head

6. “power stroke” -the cross bridge pulls actin, which slides over the myosin

9.     7. the release of adp completes the cross-bridge movement and atp attaches to myosin, breaking the actin-myosin cross bridge.