Answer:
<u>Sister chromatids are identical forms of chromatids of a chromosomes. They are mostly formed by semi-conservative replication of DNA molecule of a single chromosome.Thus they are like </u><u>'photocopies' </u><u> of original parent chromosomes; joined together at the Centromere</u>.
They are exactly similar in all ramification; with the same gene and allele compositions..
<u>However; slight differences arise between the two identical sisters due to </u><u>mutation</u><u> from</u><u> errors </u><u>at replication;and also in the length of telomere repeats.</u>
Non-sister chromatids are dissimilar forms of chromatids of a chromosomes formed when each half of a chromosome at fertilisation from separate haploid sex-cells, of each parent. fused.They contain different genetic composition;because they are not on the same homologous chromosomes.Therefore crossing -over ensure variation.
<u>However, they are genetically similar in composition; if they are contained in homologous chromosomes</u>. This is because Synapsis of bivalent of these chromosomes allow genetic material to be shared by chromosomal crossing-over between the non-sister chromatids on the chromosomes ; therefore identical genetic characteristics are shared .
Explanation:
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.
<span>The treatments for fractures are pretty common to include plenty of bed rest. Using cold compresses very frequently, taking any prescribed or over the counter nonsteroidal drugs for pain relief as needed. As the area starts to heal start to do either home based or physician recommended physical therapy to get the fracture up to par.</span>
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