Which gas has recently increased in the mesosphere, creating a rise in water vapor which has led to the formation of high-altitude clouds that are visible at night? A. Carbon Dioxide
B. Hydrogen
C. Ozone
D. Methane

True or false: (a) the strings of little red dots represent carbohydrates. (b) the model is called a bilayer because there are two main types of molecules present, lipids and proteins. (c) the many black lines represent amino acid tails. (d) this model shows membrane transport. (e) the blue ovals are hydrophobic. (f) the blue ovals represent phospholipid heads.