Scientists think that oxygen produced by the first photosynthetic bacteria contributed to the creation of the ozone layer we have today. If the ozone layer blocked visible instead of UV radiant energy, what do you think would have happened to life on early Earth? A. Life on earth would have evolved more quickly due to mutations in the DNA of early cells
B. The photosynthetic bacteria would have lost the radiant energy source they used to make a chemical energy and would have died out
C. The photosynthetic bacteria would have turned to aerobic respiration for chemical energy production
D. Photosynthetic bacteria on land would have depended on the higher energy UV light to make chemical energy instead

homeostasis is the tendency towards a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes. and this is how it applies to the integumentary system. back to top. skin functions in homeostasis include protection, regulation of body temperature, sensory reception, water balance, synthesis of vitamins and hormones, and absorption of materials. when body temperature falls, the sweat glands constrict and sweat production decreases.

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.