Download Preview material Exam #4

Preview material Exam #4 BIOL1114 May 2008 Use a #2 pencil to fill in the information on your NCS answer sheet. Put your O­Key Account Username in the boxes indicated for LAST NAME and darken the appropriate circles. Write your Name (Last,First) and “Star or Nostar” (as marked on your test form) in the space above the boxes containing your O­Key Account Username. Darken the (S or N) in the last column of the name circles depending on your test form. Enter the number 814 and darken the corresponding circles in the first 3 columns of the “Student ID.” Failure to perform this correctly will incur a ­10pt handling fee. Read all questions and answers carefully before choosing the single BEST response for each question. Feel free to ask the instructor for clarification. Use the following formulas and chart as needed. Calculators will be provided
r = # of births - # of deaths
N
1st
Letter
U
C
A
AUU
AUC
AUA
AUG
G
GUU
GUC
GUA
GUG
G = rN(K – N)
K
mRNA-Codon-to-Amino-Acid Decoder Chart
2nd Letter
C
A
U
UUU
UUC
UUA
UUG
CUU
CUC
CUA
CUG
G = rN
Phenylalanine
Leucine
Leucine
Isoleucine
Methionine;
START
Valine
UCU
UCC
UCA
UCG
CCU
CCC
CCA
CCG
ACU
ACC
ACA
ACG
GCU
GCC
GCA
GCG
Serine
Proline
Threonine
Alanine
UAU
UAC
UAA
UAG
CAU
CAC
CAA
CAG
AAU
AAC
AAA
AAG
GAU
GAC
GAA
GAG
Tyrosine
STOP
Histidine
Glutamine
Asparagine
Lysine
Aspartate
Glutamate
G
UGU
UGC
UGA
UGG
CGU
CGC
CGA
CGG
AGU
AGC
AGA
AGG
GGU
GGC
GGA
GGG
Cysteine
STOP
Tryptophan
Arginine
Serine
Arginine
Glycine
3rd
Letter
U
C
A
G
U
C
A
G
U
C
A
G
U
C
A
G The bacteria Rickettsia rickettsii causes Rocky Mountain Spotted Fever. These are obligate­intracellular organisms (They only replicate inside of the cytoplasm of a Eukaryotic cell). They are 1/10 th the volume (i.e. much smaller) than the common intestinal bacteria Escherichia coli. R. rickettsii have a double outer­membrane structure, an electron transport system in the inner membrane, and a unique ADP/ATP transporter in their outer membrane. The ADP/ATP transporter trades an ADP from inside of the bacteria for an ATP from the host cell cytoplasm. Mitochondria have a similar transporter, yet it moves ATP out of the mitochondria and into the cytoplasm while bringing ADP into the mitochondria. R. rickettsii is acquired by people from ticks, and has a 30­40% mortality (death) rate if not treated with antibiotics. A DNA sequence within the ADP/ATP transporter gene is AAGAATATAACAACG. R. rickettsii have 1.2 million (1,200,000) base pairs in their genome. A geneticist discovers an extremely large mouse and labels the mutant, “Gynormous”. When she checks the leptin level of this mouse, she discovers it is very high compared to a normal­sized mouse. In a subsequent
experiment, the scientist injects the Gynormous mice with Thyroid Stimulating Hormone (TSH) and measures thyroxin levels in the bloodstream. After the injection she finds them normal. When she breeds the Gynormous mouse with a normal mouse, all of their offspring are normal, but when she breeds the offspring among themselves, they produce a mixture of normal and Gynormous mice in a ratio of about 3:1. In another experiment, she inserts recombinant DNA into a fertilized egg produced by two Gynormous mice, in an effort to see if she can alter the mice; the recombinant DNA includes a gene that she predicts would result in the mice maintaining normal weight. Malaria is a disease caused by Plasmodium, a tiny, worm­like parasite that is carried only by mosquitoes and transmitted to humans during a mosquito bite. Once injected into a human, the parasite travels to the liver where it burrows into the host’s cells and reproduces. The parasite will multiply in a cell until the cell explodes, releasing all of the parasites, which then infect the red blood cells. A person can be infected for weeks and carry billions of the single­celled organisms before the infection causes an immune response. Symptoms of malaria can include high fevers, chills, seizures, severe muscle pain, and brain swelling and sometimes lead to death. There are four species that routinely affect humans; Plasmodium falciparum is the most deadly. Researchers have noticed that some people are naturally resistant to malaria as a result of the genetic disorder sickle­cell anemia. Sickle­cell anemia is an autosomal recessive trait that causes red blood cells to become a “sickle” shape, or shaped like a “C” rather than a rounded cell. This trait is undesirable because people that suffer from sickle­cell anemia have problems with their blood clotting in vessels, a complication that can be deadly. However, people who carry one copy of the gene for sickle­cell anemia but do not suffer from the disease are naturally resistant to Plasmodium infections. Health officials predict that malaria will strike up to a half billion people and kill at least a million people this year. In laboratories scientists are working to produce a vaccine by treating the parasites with high levels of radiation to weaken them and then inject them in lab mice. Following the vaccine, the mice do not suffer from malaria. Then, if exposed to the parasite again, the body’s immune response is swift and kills the parasite quickly. Initial testing in human patients is scheduled for sometime later this year. While the role of the mosquito as a carrier for the Plasmodium that causes malaria is common knowledge among people, few think of what prevents the parasite from affecting the mosquito. It is known that these parasites of humans can only live in certain mosquito species and live a specific portion of their life­cycle within. Scientists have uncovered several genes in mosquito species that transport malaria and these genes produce proteins that prevent the parasite from infecting the mosquitoes’ cells. A scientist collects a blood sample from a person suffering from malaria. In the lab, the scientist studying the sample adds distilled water (0% salt) to a cell (0.9% salt) so she can better view Plasmodium parasites under the microscope. Based on genetic analyses, a group of scientists conclude that four species of Plasmodium originated from only one species in a relatively short period of time. One of the most prevalent inherited neurological disorders in humans is Charcot­Marie­Tooth disease (CMT). Geneticists discovered in 2003 that one type of this disease is a result of a defect in a gene that slows nervous signal transmission. Over time, muscles weaken due to a lack of stimulation from the nerves. Researchers at the Duke Center for Human Genetics linked the gene responsible for this type of CMT to chromosome 1. Preliminary analysis has shown that an individual will not suffer from CMT if their cells have at least one working copy of the gene.
A one­legged chickadee (a small bird) wearing a plaid tam­o­shanter cap climbs up a steep mountain while on a pilgrimage in McGillicuddy’s Reeks in County Kerry, Ireland. When the chickadee reaches the summit of the mountain, he finds little plants blooming during the short growing season on the windswept alpine tundra. One such plant has dark green leaves and brilliant white flowers. On the summit at McGillicuddy’s Reek, Irish naturalist Paddy McBirder is stunned to look through his binoculars and see a one­legged chickadee hopping up the mountain. Sensing that the little bird might be exhausted from the climb, Paddy goes to an alpine spring to fetch some water. Paddy is disappointed when he notices, however, that there is a portable toilet right next to the spring, and it looks as though something from the toilet has been leaking into the spring. The spring and stream are choked with thick, green mats of algae – hardly the crystal clear mountain spring water he was anticipating. Two groups of 25 mice are monitored while running on little mouse treadmills. The mice in group A are in all ways similar to the mice in group B, except that the group A mice consume twice as much glucose while running as the mice in group B. The group A mice receive a dietary supplement; group B mice are given a placebo. Lose weight and feel GREAT! In just three weeks on Dr. T’s Advanced Nitro­Fat Burner, you too can dramatically boost your metabolism to burn fat and uncover your inner superhero! Best of all, Dr. T’s Advanced Nitro­Fat Burner helps you sculpt chiseled arms and sexy buns while driving to work, watching TV, or even sleeping. Endless crunches? Expensive gyms? Rabbit­food diet plans? Forget about them! Dr. T’s Advanced Nitro­Fat Burner is an all­natural herbal supplement that burns fat no matter what you eat or how much you exercise. Just $19.95. Call today for your 30­day supply and get ready for the new you! A research scientist working for the Food and Drug Administration is called in to study the claims made for Dr. T’s Advanced Nitro­Fat Burner. She designs an experiment in which two groups of study subjects are placed on a standard, controlled diet and participate in a moderate exercise program for three weeks. One group is given Dr. T’s Advanced Nitro­Fat Burner as directed on the label, the other group is given a placebo, i.e., a pill that looks just like the supplement but lacks the active ingredient. All the study subjects began the experiment at least 10% over the recommended Body Mass Index for their height and gender. A caliper measurement of abdominal body fat is taken from each individual at the start and the end of the experiment – larger measurements correspond to larger amounts of body fat. At the conclusion of her study, the scientist summarized a portion of her analysis into the following figure. 50 caliper abdominal fat (mm) 45 40 35 30 beginning 25 end
20 15 10 5 0 supplement placebo In the 1970’s , Michael Ryan studied sexual selection in a particular neotropical frog species (1980 Science 209 (4455): 523 – 525). He measured the size of males and the frequency of the song (i.e. the pitch or how high or how low a call they made) for the “cluck” sound that males used when calling. He also counted the number of times each male frog mated with a different female per night. The data were as follows: Dr. Al Gee extracts all the contents of the stroma and seals them in artificial membranes that lack the photosystems, electron transport chains and water splitting complexes that the chloroplasts had. He then attempts to induce the Calvin Cycle to produce sugar. Crosses between Red horses and White horses result in Roan horses as shown in the figure.