Which of the following is an example of evolution that can be studied firsthand by scientists while it happens (meaning that scientists have opportunities to perform
experiments and to measure the outcome)?
A) The gradual decent of whales from tetrapod (four-legged) land mammal
ancestors
B) A dog shedding its thick winter fur so that it can stay cooler in the summer
C) The acclimation of a person's body to the low oxygen atmosphere at high
altitudes
D) The development of antibiotic resistance in bacteria

Aflashlight produces light using energy from the batteries. in which order does the energy change form? a. from chemical to electric to light energy b. from electric to light to chemical energy c. from electric to chemical to light energy d. from light to electric to chemical energy

Match the types of competition to their descriptions

Bisphenol a (often called bpa) is a chemical found in products that people use every day, from water bottles to food containers to children's toys. unfortunately, bpa leaches out of its many products and makes its way into our bodies. what are the health effects of bpa exposure? ongoing research is finding that elevated exposure to bpa can affect a wide variety of developmental and physiological processes, but one of the first studies of bpa's health effects came about because of a simple mistake in the lab. at a laboratory at case western reserve university in 1998, geneticist patricia hunt was making a routine check of her female lab mice. as she extracted and examined developing eggs from the ovaries, she began to wonder what had gone wrong. she noticed that many of the eggs showed problems with their chromosomes, and some had irregular amounts of genetic material, which can lead to miscarriages and birth defects in mammals. she learned that a lab assistant had mistakenly washed the plastic mouse cages and water bottles with a harsh soap, releasing bpa from the plastic. knowing that bpa is an endocrine disruptor, a chemical that can enter organisms and mimic hormones, hunt set out to discover whether it had adversely affected her mice.