Natural selection<span> and selective breeding can both cause changes in animals and plants. The </span>difference between<span> the two is that </span>natural selection<span> happens naturally, but selective breeding only occurs when humans intervene. For this reason selective breeding is sometimes called </span>artificial selection<span>.</span>
Striated muscles contain repeating sarcomeres of overlapping arrays of long, thin actin and thicker myosin filaments. Myosin filaments contains the myosin heads, which are enzymes that can bind to actin, split and make use of the energy from ATP. When muscle contraction starts, myosin heads bind to actin, change their configuration on actin, liberating the products of ATP hydrolysis and causing slide of the actin and myosin filaments. The action of the proteins troponin and tropomyosin on the actin filaments regulates vertebrae striated muscle contraction. The release of calcium ions from the sarcoplasmic reticulum is triggered by the nervous stimulation which causes depolarization of muscle membrane. Calcium ions bind to troponin and thus cause or allow the tropomyosin strands on the actin filament to move so that the part of the actin surface where myosin heads need to bind is uncovered. Contraction then occurs and only stops when the sarcoplasmic reticulum pumps calcium out of the muscle interior.
So basically, what triggers the uncovering of the myosin binding site on actin is the calcium ions binding to troponin and changing configuration.
Density is mass of object per unit volume
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food chain- description 3
energy losses- description 5
pyramid of biomass- description 1
pyramid of numbers- description 4
energy flow- description 2
Answer:
The environmental factors which need to be investigated before clearing the land can involve living and non-living factors. The land clearing will remove species of animals and plants acquiring their habitat in the forest. The loss of floral species will affect the faunal species. The faunal species will extinct, decrease in number or may migrate to different locations. Therefore, complete loss of biodiversity will result.
This will also result in disturbance important cycles in nature like water, oxygen, nitrogen and carbon which will lead to disturbance of rainfall, seasonal or weather changes. Soil an important non-living factor will loose it's fertility due to soil erosion.
