Answer:
present
Explanation:
Otherwise the only similarity is that they are organelles, and can generate themselves.
Answer:
Lymphocytes
Explanation:
White blood cells ( leukocytes) is one of the formed elements of blood that provides immunity and protection against the pathogens. Different types of leukocytes are eosinophils, basophils, monocytes, lymphocytes and neutrophils.
Lymphocytes are B cells and T cells of the immune system. B cells produce antibodies against the antigen and T cells kills the harmful cells of the body. by specific cell determinants.These cells are not capable of phagocyte the pathogen.
Thus, the correct answer is option (A).
Your answer to the question is true
Answer:
When a muscle cell contracts, the myosin heads each produce a single power stroke.
Explanation:
In rest, attraction strengths between myosin and actin filaments are inhibited by the tropomyosin. When the muscle fiber membrane depolarizes, the action potential caused by this depolarization enters the t-tubules depolarizing the inner portion of the muscle fiber. This activates calcium channels in the T tubules membrane and releases calcium into the sarcolemma. At this point, <em>tropomyosin is obstructing binding sites for myosin on the thin filament</em>. When calcium binds to the troponin C, the troponin T alters the tropomyosin by moving it and then unblocks the binding sites. Myosin heads bind to the uncovered actin-binding sites forming cross-bridges, and while doing it ATP is transformed into ADP and inorganic phosphate which is liberated. Myofilaments slide impulsed by chemical energy collected in myosin heads, <u>producing a power stroke</u>. The power stroke initiates when the myosin cross-bridge binds to actin. As they slide, ADP molecules are released. A new ATP links to myosin heads and breaks the bindings to the actin filament. Then ATP splits into ADP and phosphate, and the energy produced is accumulated in the myosin heads, which starts a new binding cycle to actin. Z-bands are then pulled toward each other, thus shortening the sarcomere and the I-band, and producing muscle fiber contraction.
Answer:
Solar flare
Explanation:
They are characterized by coronal mass ejections on the sun's surface. The ejected ionized particles if thrown in the direction of the earth will cause bright aurora as they colide with the earth’s ionosphere and magnetic field. These solar storms can also affect telecommunications satellites and also electricity grid systems.
