Answer:
P wave
Explanation:
Electrocardiogram records the strength and timing of electrical activity in heart. As various regions of heart contract at different times and for different duration, the electrical activity is not constant and shows a series of rise and fall. There are three main components of ECG: P wave, QRS complex and T wave.
P wave indicates the beginning of electrical signal in the right atrium. The signal spreads in both right and left atria which leads to their contraction. As a result, blood is pumped into the ventricles and rest of the process occurs.
Answer:
B. Multiple allele means more than two forms of the same gene in the population and polygenic inheritance means more than one gene contributes to the phenotype of a trait.
Explanation:
- Multiple alleles are an alternative form of allies and can occupy the same gene ad only two of them can be found in the same organism. Such as the ABO blood group.
- A polygenic or a multiple gene inheritance is a hypothetical gene that s often difficult to characterize and traits control a multiple of genetic loci, they are relatively small and interchangeable.
