When the air pressure within the alveolar spaces falls below atmospheric pressure, air enters the lungs (inspiration), provided the larynx is open; when the air pressure within the alveoli exceeds atmospheric pressure, air is blown from the lungs (expiration).
A comparison of the three different forms of double-stranded DNA reveals that <u>Z-DNA</u> has the largest pitch per turn of the helix, whereas <u>A-DNA</u> has the widest diameter.
1. Phosphates and sugars (deoxyribose) 2. yes 3. the order of the bases aren't but what they pair with are 4. five 5. ten 6. the sequences vary between all organisms
