How can a researcher determine whether variation in a phenotypic trait is caused by environmental factors or by
genetic differences?
What will be an ideal response?
ANSWER: We can test for an environmental cause experimentally by changing one environmental
variable and measuring the effects on genetically similar subjects. For example, by
growing cuttings from an ivy plant in shade and other cuttings from the same plant in full
sun, one could see that the cuttings grown in sun will produce smaller leaves and shorter
stems. This would be evidence that the variation is due to environmental factors because
the cuttings all had the same genotype, having been taken from the same plant.
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fats, oils and proteins are all what type of nutrient
What will be an ideal response?
When using vectors to produce proteins for gene therapy, what are some of the problems that may occur and how has medical science overcome these problems?
A. cDNA produced by vectors active an immune response, tags are therefore added to help the body identify them as self. B. Proteins injected using vectors get degraded too quickly and therefore protective segments have been added to the proteins. C. Virus vectors used may actually cause disease and therefore medical technicians have removed those segments. D. RNA added via vectors to a human may cause a toxic response and so a buffer is added to the vector.
You are trying to prepare a DNA karyotype, but this time you forgot to add trypsin to your chromosome preparation. What effect would you expect to see?
A) Dyes would stain the chromosomes darker because more proteins would be present to take up the dye. B) Dyes would not stain the chromosomes as expected because proteins would not be removed from the chromatin and so would block the dye from accessing the DNA. C) Chromosomes would not condense properly, so it would be very difficult to isolate individual chromosomes. D) Chromosomes would be degraded quickly because the trypsin is necessary to promote DNA stability by adding more scaffold proteins to the chromatin. E) The chromosomes would be more difficult to pair up because the trypsin acts as a dye, creating a banding pattern that distinguishes between chromosomes.
The largest U.S. national parks are of sufficient size to maintain populations of all mammal species originally found in these parks.
a. true b. false