How does skeletal muscle contract?
What will be an ideal response?
Each contractile unit, called a sarcomere, is terminated by a Z line at each end. Actin filaments are attached to the Z lines and extend toward each other but do not touch. Overlapping both actin filaments but not extending to the Z lines is a myosin filament. Myosins, with energy supplied by ATP, attach to actin filaments and pull them toward each other, thus shortening the sarcomere, which contracts the entire muscle.
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The graph here shows the results of growing one strain of a crop plant on soils with different nitrogen contents. If a different strain of the same plant were grown on the same soils, you would predict that:
A. it would respond the same way to nitrogen supplementation because they are the same plant. B. it would respond completely differently to nitrogen supplementation because they are different strains. C. it could respond the same way or differently; different genotypes can, but may not always, respond differently to the same range of environments. D. it could respond the same way or differently; the environment has too many variables to predict. E. None of these choices is correct.
How can organisms with the same phenotype have different genotypes and vice versa, and what is the
significance?
What will be an ideal response?Which of the following additions have been made to principles of the central dogma of biology?
A. DNA information cannot be converted into RNA information. B. RNA can be used to regulate gene function. C. Protein information can be converted into DNA information. D. DNA codes for proteins.
You are attempting to link an individual to a crime. The only evidence you have is a tiny drop of blood. How can you use this drop of blood to definitively make the association?
A) You can use the sample to determine the individual's blood type. B) You can use gel electrophoresis to determine the length of the DNA found in the sample. C) You can use PCR to increase the amount of DNA available for STR analysis.