Why is the scrotum external on most male mammals? A. serves as a climate-control mechanism of cooling for the production of healthy sperm

B. serves as a climate-control mechanism of heating for the production of healthy sperm

C. allows air to circulate around this organ to help oxygenate the developing sperm

D. allows for the cooler temperatures needed for the production of the hormones in a male mammal

I’ll give brainiest:)

b. to discover aspects of the natural world.

hopefully i .

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.