A student read that putting an extra 5 psi (pounds per square inch) of air into car tires helps it burn less fuel, so she decides to test this idea. She brings her car to a race track, fills the gas tank, and drives 100 miles. She then measures how much fuel she burned. She then adds another 5 psi of air to the tires, drives another 100
miles, and measures the fuel burned. She then compares the results.

What is the controlled variable:
1. The weather conditions during each test of 100 miles
2. The speed the car is driven on
3. The race track that the car is driven on
4. All of the above

Explain:

Identify and describe the three ways that mutations affect organisms.

Calculate - analysis of compound composed of iron and oxygen yields 174.86 of fe and 75.14g of o. what is the empirical formula for this compound?

Many bird species build nests in which they raise their offspring. one of these species is known as the magnolia warbler. breeding pairs of magnolia warblers build nests out of pieces of grass and twigs. the female warbler will then lay her eggs in the nest and sit on the eggs for a few weeks until they hatch. after the offspring have hatched, the female will continue to sit on the newborn chicks to keep them warm. both the male and the female bring food for the offspring to eat until the young are mature enough to find food on their own. which of these most likely describes why birds such as the magnolia warbler build nests in which to raise their offspring? a. nest building decreases the amount of energy used by the parent birds to raise their offspring to adulthood. b. nest building increases the probability that the offspring will survive and eventually produce offspring of their own. c. nest building decreases the amount of food that the offspring require the adult birds to provide. d. nest building increases the probability of the offspring being located by airborne predators.