Simple. Air has mass. And if air has mass it also has weight. You can feel air when the wind blows. Or do an experiment. Weigh an empty container. Then pump it to a vacuum. Weigh it again. The difference is the weight of the air inside.
The area is called the anterior fontanel and closes anytime between 9 and 18 months of age.
Answer:
C
Explanation:
Without crossing over, each chromosome would be either maternal or paternal, greatly reducing the number of possible genetic combinations, which would greatly reduce the amount of genetic variation between related individuals and within a species.