1. How does RNA differ from DNA?2. What are three types of RNA? What is the function of each?
3. Define mutation. Give one example of how a mutation might occur.
4. The base sequence of the gene coding for a short polypeptide is CTACGTAGGCGATTACTA.
What would be the base sequence of mRNA transcribed by this gene?
Using the genetic code chart (p172 Audesirk), give the amino acid sequence of the polypeptide translated from this mRNA
5. Some antibiotics such as erythromyacin and streptomyacin bind to the small robosomal subunit and inhibit translation. Why do these drugs kill bacteria? How can bacteria evolve so that they become resistant to such antibiotics?
6. Select terms from the list provided to compare DNA replication, transcription and translation.(10 pts)
+1 (transcription initiation site) origin of replication
3'--> 5' N terminal to C terminal
AUG (start codon) promoter
5'-->3' polypeptide
amino acids RNA
aminoacyl-tRNA synthase ribonucletides
deoxribonucleotides (A,C,T,G) RNA polymerase
DNA ribosome
DNA Polymerase ribosome binding site
mRNA stop condon
terminator
DNA replication Transcription Translation Macromolecule
synthesized. . . Monomers
polymerized. . . What molecule is used
as the template ?. . . In what direction is the new
molecule synthesized?. . . What enzyme or molecule
brings about the
polymerization reaction?. . . The site on the template molecule
where the RNA polymerase
or ribosome binds is called?. . . The site on the template molecule
where synthesis begins is called?. . . The site on the template molecule
where synthesis ends is called?. . .
Ch 11 SG-
(review online at http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/cell_division.html
)
Answer the following questions in complete sentences on your own paper. (3.3 points each)
1. In what ways are mitosis and meiosis similar. In what ways are they different?2. Both nerve cells in the adult human nervous system and heart muscle cells remain in the G0 portion of interphase. In contrast, cells lining of the small intestine divide frequently. Discuss this difference in terms of why strokes and heart attacks are so dangerous. What would happen to tissues in the small intestine if some disorder or a drug blocked mitosis in all cells of the body?
3. Cancer cells divide out of control. Chemotherapy and radiation therapy typically cause the loss of hair and the lining of the intestinal tract, producing severe nausea. What can you infer from this about the mechanism of these treatments?
4. Vinblastine and taxol (which is extracted from the bark of the Pacific yew) are both drugs which interfere with the assembly of microtubules.How would these drugs function to treat cancer?
5. Many species can reproduce either sexually or asexually, It is often when the environment changes in some way that is unfavorable to an existing population that the organisms begin to reproduce sexually. Discuss the advantages and disadvantages this behavior might have on the evolutionary survival of the species or on the survival of individuals.
BONUS: (Give this a try- it really isn't that hard)When a population of cells is examined with a microscope, the percentage of cells in the M phase is called the mitotic index. The greater the proportion of cells dividing, the higher the mitotic index. In a particular study, cells from a cell culture are spread on a slide, preserved and stained, then inspected with a microscope. A hundred cells are examined: 9 cells are in prophase; 2 cells are in anaphase; 4 cells are in telophase; 5 cells ar in metaphase; 2 cells in anaphase; 4 cells in telophase; the remainder, 80 cells, are in interphase. Based on this information, answer the following questions:
a. what is the mitotic index for this cell culture? 1. A man has six
fingers on each hand and six toes on each foot. His
wife and their daughter have the normal number of digits. Extra digits
is a dominant trait. What fraction of this couple's children would be
expected to have extra digits.
2. Bill and his wife Marie hope to have children. Both have notably flat feet and long eyelashes and they tend to sneeze a lot( hence the name of the achoo syndrome)A dominant allele gives rise to each of these traits: A (foot arch), E (eyelash length), S (chronic sneezing). Bill is heterozygous of all three traits and marie is homozygous for all three traits.
a. What is Marie's phenotype? What is Bill's?
b. Marie becomes pregnant three
times. What is
the probability that each child will show all three of Bill's traits?
Of Marie's?
c. What is the probability that
each child
will have short lashes, high arches and no chronic tendency to sneeze?
3. Imagine you are a genetic counselor and a couple
planning to start a family came to you for information. Charles was
married once before and his first wife had a child which has cystic
fibrosis. The brother of his current wife, Elaine, died of cystic
fibrosis. What is the probability that Charles and Elaine will have a
baby with cystic fibrosis? (Neither Charles nor Elaine has cystic
fibrosis).
4.
In
mice, black coat color (B) is dominant to white(b). At a different
locus, a dominant allele (A)produces a band of yellow just below the
tip of each hair in mice with black fur. This gives the
frosted appearance known as agouti. Expression of the recessive
allele(a) results in a solid coat color. If mice that are heterozygous
at both
loci are crossed, what will be the expected phenotypic ration of
their offspring.
5. Kernel color in wheat plants is determined by two pairs of genes. Alleles of one pair show incomplete dominance over alleles of the other pair. For the one gene pair at one locus on the chromosome, allele A1 imparts one dose of red color to the kernel whereas A2 does not. A second allele B1 gives one dose of the red color to the kernel while B2 does not. A kernel with genotype A1A1B1B1 is dark red. A kernel with genotype A2A2B2B2 is white. All other genotypes have kernel colors between these extremes.