Heart rate of men is lower than women because size of the heart in men is 25% larger than in women. Larger heart can pump more blood than smaller heart in one beat. Another reason of low heart rate in men than women is capacity of lungs in men is 25-30% higher than women. These are 2 reason of low heart rate or pulse rate in men than women.
Because they are typically smaller. Large animals have a slower heart rate than small animals. Some women of course will have a slower heart rate than some men.