B is the most efficient answer
The process of
prenatal development occurs in three main stages and they are listed in order;
<span>1. </span>Germinal Stage - begins at conception when the
sperm and egg cell joined in one of the two fallopian tubes.
<span>2. </span>Embryonic Stage - begins at the beginning of
the third week after conception. This stage plays an important role in the
development of the brain.
<span>3. </span>Fetal Stage - begins during the ninth week
and lasts until birth.
Answer:
conduction convection and radiation
Explanation:
I think
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.