Answer:
Cell membrane
Explanation:
The cell membrane is a flexible and permeable skin surrounding a cell.
Answer:
The correct answer will be option A.
Explanation:
The electrical impulses are generated in the sino-atrial node or SA node, a mass of cells which generates impulse in the upper atrium.
This electrical impulse transmits from the sino-atrial node to the atrio-ventricular node in the lower portion of the upper atrium through the internodal pathway- the pathway composed of atrial cells.
Once the impulse reaches the AV node, it is transferred to the ventricular portion of the heart through Bundle of His presence in the ventricular septum. This bundle of his divides into left and right ventricles through bundle branches and stimulates both the ventricles.
Thus, option-A is the correct answer.
Red blue green purple r r d f. F f t brown blue grey dark blue purple
Half life is the time taken by a radioactive isotope to decay by half of its original mass. In this case the half life of carbon-14 is 5500 years.
The original mass is 30 g and the new mass is 3.75 g.
New mass = Original mass × (1/2)^n, where n is the number of half lives;
3.75 = 30 × (1/2)^n
1/8 = (1/2)^n
n = 3
Thus, the time taken will be; 3 × 5500 = 16500 years.