Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species?
a. river otter
b. mouse living in a temperate broadleaf forest
c. mouse living in a desert
d. beaver

they both go up but then go back down. they both end lower than they started. lastly, they both are competitive/the second on.

explanation:

maybe because its impossible for balloons to lift a whole entire house.

la transducción de señal ocurre cuando una molécula de señalización de fluido extracelular activa un receptor de superficie de la célula.

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.