Answer:
Option (A).
Explanation:
Muscle contraction may be defined as the physiological process of the activation of tension generating sites that occur within the muscle fibers. Actin, myosin, troponin and other proteins are important for muscle contraction.
The calcium ion is important for the muscle contraction. The binding of calcium with troponin causes the movement of tropomyosin out of the grooves between the actin molecules during muscle contraction.
Thus, the correct answer is option (A).
<span>b The growth of teeth in chickens supports the hypothesis of a common ancestor between birds and reptiles. This is a generally accepted hypothesis, and i'd go with this answer. Obviously we can't say whether chickens will have teeth with certainty, the chickens with teeth are clearly still chickens, and a baby croc isn't hatching out of a chicken egg any time soon.
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Cytoplasm is the gel-like fluid that fills the cell and surrounds the organelles.
Genetic engineering is the
direct treatment of an organism’s genome using biotechnology. It is a set of
technologies used to alter the genetic makeup of cells, together with the
transport of genes within and across species boundaries to produce improved
organisms. An example would be to
protect plant from insect damage, it can be made into a transgenic plant.
Transgenic plant are called genetically modified organisms (GMO) because there
is a gene added or removed in the original plant to obtain a set of
characteristic such as insect damage.