A theory explaining the structure of the earth's crust and many associated phenomena as resulting from the interaction of rigid lithospheric plates which move slowly over the underlying mantle.
Answer: Option A.
first degree heart block
Explanation:
First degree atrioventricular block is a condition that is associated with electrical condition system of the heart in which the electrical impulses is conducted from the cardiac atria to the ventricles via atrioventricular node in a slow manner compare to the normal transmission.
It is first degree great block because it is characterized by prolong PR interval on an electrocardiogram (ECG) to more than 200 msec and atrial impulse is transfered to the ventricles, which lead to regular ventricular rate.
The PR interval of the surface ECG is measured from the start of atrial depolarization (P wave) to the commensement of ventricular depolarization or QRS complex.
Answer: B. Random mating
Explanation:
Random mating can be define as the individuals of one sex are potentially be the partners of the members of the opposite sex. It is also called as panmixia. Here, the chances of getting mates is certain. It occurs in large population. The physical and geographical barriers can prevent the random mating. In this allelic frequencies will not vary if the mating is conducted in a single population.
