Answer will give 75 points

1. eight double-stranded dna molecules resulted after three complete cycles of a single dna double helix. how many molecules will result after 10 cycles? 20 cycles? 30 cycles? (hint: you’ll need a calculator that can do logarithmic functions)

2. how do the amplified dna strands compare with the original dna strands? (answer should include: are the sequences the same/different? length the same/different? )

3. after 30 cycles, what percent of the dna in the test tube would be like the original dna strand? what percent would be like the target segment?
could dna be amplified with only one primer? why or why not?

4. primers will sometimes complement each other and create a dna product. this creates a problem when trying to determine what came from your target dna and what was created by the primer complementation.

5. what could you add when you design your pcr experiment to make sure that only dna product you are seeing is coming from your target dna? (hint: what do you need for any experiment? )

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.

Rease is an enzyme used by plants to break down urea (a nitrogen-containing compound) into carbon dioxide and ammonia. urease urea > > > carbon dioxide and ammonia ammonia is broken down by plants into a nitrogen source plants need to grow. thus, plants could not use urea as a nitrogen source unless it was first converted to ammonia. in soybean plants there are two different kinds of urease, one produced in the seeds and the other produced in the leaves of the plant. three types of soybean plants were used in a set of experiments: normal soybeans and two mutant strains, one lacking the urease in the seeds only (strain 1) and one lacking urease in the leaves only (strain 2). experiment 1 separate areas in a field were planted with normal, strain 1, and strain 2 soybeans. all types of soybeans appeared to grow, flower, and produce seeds equally well. there were no externally detectable differences among the strains. experiment 2 small pieces of plant leaves of equal weight were obtained from each type of soybean plant and separately placed on media in culture dishes. tissue growing in this way will become an unorganized clump of cells referred to as callus. to provide a controlled nitrogen source, half the tissue samples of each type were placed on media containing urea, and the other half of the samples were placed on media containing ammonia. after 30 days, the weight gain for each of the callus samples was determined. results are shown in the table below.

If this person had son, what, sex chromosome did they give their son? a. x b. y c. neither d. we need more information to know for sure