What did mendel's cross-pollination of pea plants prove a. each parent only passes on one'half of its hereditary factors to each offspring b. it takes four generations of offspring to identify the parents' factors c. there is no such thing as a true-breeding plant; they all have hidden factors d. inherited factors combine in offspring to create entirely new characteristics

The image shows embryos of three vertebrate classes

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.

Which action is a reflex action. a. asking for coffe in a cold climate b. blinking when light is flashed in the eyes c. drinking water when thirsty. d. swallowing food e. taking an exam