#Question id: 15907
#Unit 5. Developmental Biology
#Question id: 1794
#Unit 4. Cell Communication and Cell Signaling
Which of the following statements is TRUE of natural antibodies?
#Question id: 13131
#Unit 10. Ecological Principles
Biologists performed an experiment with flies to examine the effects of population size on the maintenance of genetic variation and on egg-to-adult survival. From a large source population, they randomly assigned eggs to three experimental populations of size N, equal to 20, 60, and0100. For later generations, they collected N eggs from each population and moved them into identical vials that co0ntained f2re0sh me4d0ium. Th6e0y coun8te0d the number of adult flies that emerged and used tissue samples from the adults for genetic analyses. Genetic variation was measured by scoring alleles at several polymorphic loci and expressed as the average number of alleles at those loci. The results are summarized in Figure 1 and Figure 2 below.
The numbers of adult flies that emerged from the three populations in the first generation are closest to which of the following?
#Question id: 33491
#Unit 2. Cellular Organization
#Question id: 12000
#Unit 10. Ecological Principles
The graph below shows the growth rates of populations of bacteria that have evolved for many generations at different culture temperatures (25°C, 30°C, and 35°C). Each population grows over only a limited range of temperatures (its thermal niche), which are bounded by its critical thermal limits. Within this range, growth rate increases with temperature up to a maximal value and then declines rapidly with increasing temperature. Growth rates are known to be the major determinant of fitness for these bacteria.
Which of the following is true concerning the thermal dependence of growth rate between 25°C and 30°C in these populations?