Constitutive mutations produce elevated enzyme levels at all times; they may be of two types: O c or I . Assume that all other DNA present is wild-type. Outline how the two constitutive mutants can...

For each of the following partial diploids indicate whether enzyme synthesis is constitutive or inducible (see Problem 17.5 for dominance relationships): (a) I + O + Z + Y + /I + O + Z + Y + , (b) I...

Assume that you have discovered a new strain of E. coli that has a mutation in the lac operator region that causes the wild-type repressor protein to bind irreversibly to the operator. You have named...

Assume that an animal is capable of producing 100 mil-lion different antibodies and that each antibody contains a light chain of 220 amino acids long and a heavy chain of 450 amino acids. How much...

Human females have 23 different chromosomes, whereas human males have 24. Is the statement true? Explain why or why not.

How is it that proteinprotein interactions that are too weak to cause proteins to assemble in solution can nevertheless allow the same proteins to assemble into complexes on DNA?

According to Newtons laws of motion, an ion exposed to an electric field in a vacuum would experience a constant acceleration from the electric driving force, just as a falling body in a vacuum...

The nuclear pore complex (NPC) creates a barrier to the free exchange of molecules between the nucleus and cytosol, but in a way that remains mysterious. In yeast, for example, the central pore of...

At first glance, it would seem a dangerous strategy for the thymus to actively promote the survival, maturation, and emigration of developing T cells that bind weakly to self peptides bound to self...

What is the difference between haploid and diploid cells? Are your skin cells haploid or diploid? What about germ cells? Gametes?

Provide examples to support or refute this statement: The products of meiosis are always haploid cells, whereas the products of mitotic division are always diploid cells.

A fern with genotype AA Bb Cc dd Ee mates with another fern with genotype aa Bb CC Dd ee. What proportion of the offspring will be heterozygous for all genes? Assume the genes assort independently....

When human cancer cells are exposed to ultraviolet (UV) light at 90 mJ/cm 2 , most of the cells undergo apoptosis within 24 hours. Release of cytochrome c from mitochondria can be detected as early...

Use the Internet to find three examples of viruses that infect humans but are not mentioned in the chapter. Describe the symptoms associated with each infection.

Create a graph showing the number of species in each group of fungi. Which group is least diverse? Based on the habitats and reproductive structures of these fungi, propose an explanation for their...

Fas ligand is a trimeric, extracellular protein that binds to its receptor, Fas, which is composed of three identical transmembrane subunits (Figure Q183). The binding of Fas ligand alters the...

Three babies are born in the hospital on the same day. Baby X has type B blood; Baby Y has type AB blood; Baby Z has type O blood. Use the information in the following table to determine which baby...

Review figure 19.5, which shows the alternation of generations in plants. Compare and contrast the life cycles of zygomycetes, ascomycetes, and basidiomycetes with the basic plant life cycle. Figure...

Trace the movement of food in the digestive tract from mouth to anus.

Refer to figure 33.18 and the chapter content to answer the following questions. 1. Review the Survey the Landscape figure in the chapter introduction and the Pull It Together concept map. How do the...

What is meant by the mixing point? For a multistage extractor, is the mixing point on a triangular diagram the same for the feeds and the products?

Fifty mol% propylene in propane is separated with silica gel. The products are to be 90 mol% propylene and 75 mol% propane. If 1,000 lb of silica gel/lbmol of feed gas is used, can the desired...

Two feedsF at 7,500 kg/h containing 50 wt% acetone and 50 wt% water, and F0 at 7,500 kg/h containing 25 wt% acetone and 75 wt% waterare to be extracted in a system with 5,000 kg/h of...

An acetoneethanol mixture of 0.5 mole fraction acetone is to be separated by batch distillation at 101 kPa. Vaporliquid equilibrium data at 101 kPa are as follows: (a) Assuming an L=D of 1.5 times...

Filtration tests were carried out with a plate-and-frame filter press at 20C under the following conditions: s = 2,710 kg/m 3 , filter area 0.37 m 2 , filtrate m = 0.001 N-s/m 2 , and c F = 10.037...

It is estimated that each electron pair donated by NADH leads to the synthesis of approximately three ATP molecules, whereas each electron pair donated by FADH 2 leads to the synthesis of...

What two properties define a stem cell? Distinguish between a totipotent stem cell, a pluripotent stem cell, and a precursor (progenitor) cell.

Identify whether the following contain totipotent, pluripotent, or multipotent cells: (a) Inner cell mass (b) Morula, (c) Eight-cell embryo (d) Trophectoderm.

Tim Hunt shared the 2001 Nobel Prize in Physiology or Medicine for his work in the discovery and characterization of cyclin proteins in eggs and embryos. Describe the experimental steps that led him...

A DNA library is a collection of clones, each containing a different fragment of DNA, inserted into a cloning vector. What is the difference between a eDNA and a genomic DNA library? You would like...

Use the key provided below to determine the amino acid sequence of the polypeptide produced from the following DNA sequence. lntron sequences are highlighted. Note: Not all amino acids in the key...

Before you begin your analysis of the nucleotide sequences, use the data in the following figure to make a prediction about the sequence that you would expect to be most similar to the one from...

Does either tree in Figure 4.10 support hypothesis B in tree B? Explain. 125 rDNA k-casein

What might happen if Bt corn affects non-target organisms such as beneficial insects or harmless insects?

What might happen if ECB became resistant to Bt?

What genetic information can be obtained from a Punnett square? What genetic information cannot be determined from a Punnett square?

A researcher studied six independently assorting genes in a plant. Each gene has a dominant and a recessive allele: R black stem, r red stem; D tall plant, d dwarf plant; C full pods, c constricted...

A normal woman, whose father had hemophilia, marries a normal man. What is the chance that their first child will have hemophilia?

In a species of tree, seed color is determined by four independently assorting genes: A, B, C, and D. The recessive alleles of each of these genes (a, b, c, and d) produce abnormal enzymes that...

In Drosophila, the genes st (scarlet eyes), ss (spineless bristles), and e (ebony body) are located on chromosome 3, with map positions as indicated: st....... ss ........ e 44.......58.......70 Each...

A partial (5 subterminal) nucleotide sequence of a prokaryotic mRNA is as follows: 5-.....AGGAGGCUCGAACAUGUCAAUAUGCUUGUUCCAAUCGUUAGCUGCGCAGGACCGUCCCGGA.. . . . . 3 When this mRNA is translated, what...

The four core histones are relatively small proteins with a very high proportion of positively charged amino acids; the positive charge helps the histones bind tightly to DNA, regardless of its...

Nucleosomes bind DNA so tightly that they cannot move from the positions where they are first assembled. Is the statement true? Explain why or why not.

Traumatic brain injury can occur when a person receives a strong blow to the head or when an object enters the brain through the skull. Symptoms can include nausea, loss of sight or hearing, memory...

Describe how the circulatory system connects the digestive system with the urinary system.

Explain the similarities and differences among the three types of muscle tissue.

What change in blood vessel diameter would raise blood pressure?

Classify each of the following descriptions as either a proximate or an ultimate cause of behavior. For all proximate causes, speculate about a possible ultimate cause of the behavior. a. A surge of...

A liquid of 27 wt% acetone and 73 wt% water is to be separated at 25C into a raffinate and extract by multistage, countercurrent liquid liquid extraction with a solvent of pure 1,1,2-trichloroethane....

One hundred kmol/h of a saturated-liquid mixture of 12 mol% ethyl alcohol in water is distilled continuously using open steam at 1 atm introduced directly to the bottom plate. The distillate required...

Write the overall reaction of oxygen-generating photosynthesis. Explain the following statement: the O 2 generated by photosynthesis is simply a by-product of the pathway's generation of...

Microinjection of an antibody known as EAGE, which reacts with the "hinge" region of the subunit of COPI, causes accumulation of Golgi enzymes in transport vesicles and inhibits anterograde...

Where are stem cells located in plants? Where are stem cells located in adult animals? How does the concept of stem cell differ between animal and plant systems?

Cytokinesis, the process of cytoplasmic division, occurs shortly after the separated sister chromatids have neared the opposite spindle pules. How is the plane of cytokinesis determined? What are the...

In the 1960s, the drug thalidomide was prescribed to pregnant women to treat morning sickness. However, thalidomide caused severe limb defects in the children of some women who took the drug, and its...

According to health experts, saturated fatty acids, which come from animal fats, are a major factor contributing to coronary heart disease. What distinguishes a saturated fatty acid from an...

Mobile DNA elements that can move or transpose to a new site directly as DNA are called DNA transposons. Describe the mechanism by which a bacterial DNA transposon, called an insertion sequence, can...

Compare/contrast bacterial and eukaryotic gene expression mechanisms.

Hoechst 33258 is a chemical dye that binds specifically to DNA in live cells, and when excited by UV light, it fluoresces in the visible spectrum. Name and describe one specific method, employing...

The membrane potential in animal cells, but not in plants, depends largely on resting K + channels. How do these channels contribute to the resting potential? Why are these channels considered to be...

If you were planning a trip to one of the countries listed in number 5, would you rather be told the death rate or the number of cases and deaths in each country? Explain.

Compare the structure of WNV to that of HIV.

What inferences can you draw from these data about how avian flu is transmitted to humans? Explain each one, referring to the data you used in developing that inference.

What molecule does the H stand for in the name of both viruses, where is the H molecule located on the virus, and what role does the H molecule play in the life cycle of the virus?

The PI3K/AKT signaling pathway is aberrant in a wide variety of cancers. In soft-tissue sarcoma (STS) cells, AKT1 activation induces cell motility and invasiveness, which leads to aggressive...

While searching for images, you find a drawing of an early swamp with a dragonfly. The caption says the dragonfly has a wingspan of 2 feet. Use 2 feet as the scale value. The size of the dragonfly...

What other factors might enter into a growers decision about whether to plant Bt corn?

Extending this investigation: Visit one of the many interactive maps on avian influenza. Two particularly good ones are offered by the British Broadcasting group in the United Kingdom:...

The nematode worm C. elegans is amenable as a model for siRNA studies. In this experiment, adult nematodes are fed bacteria expressing a double-stranded RNA to suppress the expression of the unc18...

Which substance worked best? What does this tell you about the composition of wallpaper paste?

Grass forage and hay consist largely of structural carbohydrates in the form of fiber, primarily cellulose. The fiber provides the raw material necessary for the growth and maintenance of microbial...

Why was it important for a systematist to identify the known cetacean species from which DNA was extracted and sequenced?

Which cetacean does the unknown sample most closely match?

Phylogenetic trees are hypotheses that show a pattern of evolutionary relationships, based on analyses of multiple characters, for multiple taxa. A phylogenetic tree implies a chronological sequence...

1. Recognize potential issues and major topics in the case. What is this case about? Underline terms or phrases that seem to be important to understanding this case. Then list 3 or 4 biology related...

Divergence of cetacean species occurred within the last 50 to 65 million years (OLeary and Geisler, 1999). Explain the difference between the use of a fragment of hypervariable mitochondrial DNA as a...

An attorney defending a whale meat supplier accused of improperly labeling meat would most likely claim that the inferences drawn from the prosecutions evidence were questionable. Provide a potential...

Which of the trees based on molecular sequence data shown in Figure 4.10 supports hypothesis A in tree B? Explain.

List three characters that you could observe in living whales that white-tailed deer or other even-toed ungulates do not seem to share.

Molecular data can also be used to examine relationships between organisms, but the inaccessibility of comparative DNA samples for extinct taxa limits the usefulness of these data. Evidence for...

List four animal phyla that you would expect to find living in the aquatic environments of the Carboniferous including swamps and oceans.

At the first meeting, the artists from Wall Works gave the biology students a list of organisms from their image files. Please evaluate whether or not the organisms listed in the following table...

How long ago was the Carboniferous?

List five other terrestrial organisms (not listed elsewhere in this case) that likely lived during the Carboniferous. Include organisms from at least three kingdoms. You may use common names.

Could there be a food chain without herbivores and carnivores?

What is an indicator species? How are indicator species used to assess pollution levels in the environment?

For each of the following characteristics, indicate whether the trait is common to Phylum Arthropoda or specific to certain classes of arthropods: wings, chewing mouthparts, jointed appendages,...

In a few sentences, what were Mendels key ideas about inheritance?

The following pedigree shows the inheritance of a recessive trait. Unless there is evidence to the contrary, assume that the individuals who have married into the family do not carry the recessive...

A geneticist crosses tall pea plants with short pea plants. All the F 1 plants are tall. The F 1 plants are then allowed to self-fertilize, and the F 2 plants are classified by height: 62 tall and 26...

The Boston barberry is an imaginary plant with a diploid chromosome number of 4, and Boston barberry cells are easily grown in suspended cell cultures. 3H-thymidine was added to the culture medium in...

Which of the following pairs of DNA sequences could qualify as target site duplications at the point of an IS50 insertion? Explain. (a) 5-AATTCGCGT-3 and 5-AATTCGCGT-3 (b) 5-AATTCGCGT-3 and...

A nutritionally defective E. coli strain grows only on a medium containing thymine, whereas another nutritionally defective strain grows only on a medium containing leucine. When these two strains...

A Drosophila geneticist crossed females homozygous for three X-linked mutations (y, yellow body; B, bar eye shape; v, vermilion eye color) to wild-type males. The F 1 females, which had gray bodies...

Eight independently isolated mutants of E. coli, all of which are unable to grow in the absence of histidine (his), were examined in all possible cis and trans heterozygotes (partial diploids). All...

Use the Internet to research cosmetic surgery. Write a paragraph explaining how a plastic surgeon might manipulate each of the four main tissue types.

Distinguish between the following. a. Organs and organ systems b. Simple squamous and stratified squamous epithelial tissue c. Loose and dense connective tissue d. Skeletal and cardiac muscle tissue...

Describe the events that occur during one cardiac cycle.

What is the function of heart valves? Why might a person with a leaky heart valve feel short of breath?

Referring to figure 30.4, speculate about which blood type is considered the universal donor and which is called the universal recipient. Explain your answer. Figure 30.4 Donor blood group AB A A...