<span>When you are pregnant, you do not ovulate because you have already fertilized an egg and it is embedded into the uterus where it is growing into a baby. The body knows this, so it does not shed the uterine lining. The shedding of this lining is triggered by hormones which change when the body is pregnant. During pregnancy, a large amount of progesterone is initially produced which helps to prevent the lining from shedding. If you are not pregnant, your progesterone level will begin to decline at the end of your cycle, triggering the shedding of the lining and the period. Birth control pills alter your hormones to mimic a pregnant state. This will prevent the body from releasing an egg and then shedding the uterine lining.</span>
Lactic acid buildup when you’re exercising causes a build up of oxygen. Your body cannot break down glucose in the blood. So, your heart beat increases because there is more oxygen than normal needing to be pumped throughout the body.
In short terms: because your heart needs to pump more oxygen, it is pumping faster causing a faster heart rate.
Explanation:
They can't tranfuse because they will have an ABO incompatibility reaction. In an ABO incompatibility reaction, your immune system attacks the new blood cells and destroys them
If you have type AB you have both A and B antigens. Therefore you have B too that's why you can't only tranfuse with A after all you have to have to have both types.
To have an overall positive or negative charge. (as opposed to neutral one)