Genetic drift is defined as a shift in the allelic frequency of a population. This can be caused by natural selection which is the differential survival and reproduction of individuals across a population due to differences in phenotype. Natural selection favors particular traits in a population hence these individuals are able to reproduce while the individuals with disadvantageous traits will pass their genes to succeeding generations. This way the allelic frequency of succeeding generation will be diferent from that of the parent population.
Answer:
3) Temperature
4) gill covering opening and closing per minute
5)as temperature rises, the rate of gill covering opening and closing per minute increase until the temperature reaches 27℃ where the rate decreases
Explanation:
4) you can adjust and control the temperature in an experiment
5) you can't control the gill opening and closing rate
The answer is red for the highest surface temp of a star.
Answer:
Power stroke (myosin head bends) coupled with the release of ADP and phosphate
Explanation:
Muscle contraction results from myosin heads adhering to actin and attracting it inwards. It uses ATP. Myosin adhers to actin at a binding site of its globular actin protein and adheres at another binding site for ATP (hydrolyzed ATP to ADP, Pi and energy)
ATP binding prompts myosin to detach from actin, ATP is changed to ADP and inorganic phosphate, Pi by ATPase. The energy formed at this process orientates myosin head to a “cocked” direction.
The myosin head goes in the direction of the M line, holding the actin with it in the process causing the filaments to orientate nearly 10 nm in the direction of the M line--- power stroke (force is produced), the sarcomere reduces in length and the muscle contracts.
Note: The power stroke is seen when ADP and phosphate disattaches itself from the myosin head.
At the terminal point of the power stroke, the myosin head as low-energy, followed by ADP release.
The attached image shows the cross-bridge muscle contraction cycle, which is activated by Ca2+ sticking to the actin active site. And how actin moves in relation to myosin.