During the replication process, which enzyme(s) unwind(s) the double-stranded DNA? 1.) DNA ligase
2.) DNA polymerase
3.) DNA primase and helicase
4.) DNA gyrase and topoisomerase

Awic dietitian is meeting with a client who has an infant and a young child. the mother says that the young child is a very picky eater and will only eat crackers and juice. the health worker notices that the child's hair is brittle, his nails tear easily, and the skin inside his lower eyelids is very pale. these are all signs of iron deficiency.

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.

Ascientist is examinin the cell is disrupted when she damages one specific type of macromolecule g the function of macromolecules in a cell she notices that movenent of large molecules into and out of