Two teams of agriculturists used different methods to improve production. Team Corn used organic methods, and team Plum used gibberellins for their crops. Which team had plants with longer stems? Hint: Gibberellins are hormones that cause the plant to grow. When gibberellins are applied to plants by scientists, the stems grow longer. Some gardeners or horticulture scientists add gibberellins to increase the growth of plants. Dwarf plants (small plants), on the other hand, have low levels of gibberellins ( Figure below ). Another function of gibberellins is to stop dormancy (resting time) of seeds and buds. Gibberellins signal that it's time for a seed to germinate (sprout) or for a bud to open.
Ans: Plum

John likes to ride on hot air balloon. Last month he rode on a balloon with his friend Keith. First they were at the ground-level. They called it camp A. Then they rose to the height of three miles. They called it camp B. Eventually, they reached six miles above ground. They called it camp C. Where the air would be denser, camp A or camp B? Hint: As shown here, pressure decreases to less than 25% of ground-level atmospheric pressure when we get to an altitude of about six miles. Since this is a common cruising altitude for commercial airplanes, pressurized cabins are needed for the comfort and survival of the passengers. This is because the density of the air decreases along with the decreasing air pressure, so there is less oxygen in a breath of air. You've probably noticed this effect in high-mountain areas, as it often feels harder to breath.
Ans: camp A

There are two lakes in southern Indiana that are popular places for families of nearby cities to visit for picnics and parties. Lake Mahoe is right next to a large farm that grows all kinds of crops for the town. The owner of the farm also rents out his barn regularly so people can use it for celebrations. Lake Tresco is located near a school and children will often come play at it during recess. Which lake will have more algae? Hint: Huge amounts of chemicals, such as fertilizers and pesticides, are applied to farm fields (see Figure below ). Some of the chemicals are picked up by rainwater. Runoff then carries the chemicals to nearby rivers or lakes. Dissolved fertilizer causes too much growth of water plants and algae. This can lead to dead zones where nothing can live in lakes and at the mouths of rivers. Some of the chemicals can infiltrate into groundwater. The contaminated water comes up in water wells. If people drink the polluted water, they may get sick.
Ans: Lake Mahoe

Due to economic sanctions and trade embargoes, Cuban citizens primarily use cars designed in the late 1940s and early 1950s. These cars contain engines that were designed before the introduction of the catalytic converter. Meanwhile trade relations between nearby Panama and Japan have enabled the citizens of Panama to drive cars with the most up to date catalytic converter technology possible. Which country's cars, Cuba's or Panama's, will emit less carbon monoxide? Hint: Gasoline-powered vehicles emit a lot of harmful materials. Nitrogen oxides are formed when atmospheric nitrogen reacts with oxygen at the high temperatures found in a car engine. Carbon monoxide is a by-product of incomplete combustion of hydrocarbons. Evaporated and unused fuel releases volatile hydrocarbons into the atmosphere to help form smog. The presence of a catalytic converter in the exhaust system of the car causes these materials to react and be changed into less harmful products.
Ans: Panama's