Radioactive iodine (131I) is commonly used in medical situations for diagnosing and treating thyroid conditions. The most common isotope of iodine that is not radioactive is 127I
Chemically, what is the difference between 127I and 131I? What do they have in common?
The difference between the two isotopes of iodine is their weights (or mass). This is due to a difference in the number of neutrons present in each isotope. These isotopes have in common their atomic number (number of protons), which is what makes them both iodine.
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Regions at the ends of chromosomes that prevent chromosomes from sticking to each other are called ____
a. satellites b. telomeres c. centromeres d. q zones e. p zones
. F. Skinner first introduced operant conditioning experiments. What happens in these experiments?
A. An animal learns to associate its behavioral response with a fixed action pattern. B. An animal learns to associate its behavioral response with an instinct. C. An animal learns to associate its behavioral response with its biological clock. D. An animal learns to associate its behavioral response with a reward or a punishment. E. An animal learns to associate its behavioral response with a conditional stimulus.
Which group has silica shells similar to those of diatoms?
A) Apicomplexans B) Ciliates C) Euglenids D) Dinoflagellates E) Radiolarians
Assume a population is in Hardy-Weinberg equilibrium for a character with these genotypic frequencies: AA = 0.25, Aa = 0.50, and aa = 0.25. If you remove all the homozygous dominants and allow the remaining population to reproduce (again under Hardy-Weinberg conditions), what will be the frequency of homozygous dominants in the next generation?
a. 0.11 b. 0 c. 0.22 d. 0.44 e. 0.50