You identify a previously unidentified plant species and decide to study its genetics. You establish true breeding strains for leaf shape (longer than wide vs equal length and width) and flower color (white vs. yellow). When you perform a dihybrid cross with these strains, you find that your results are very different than those predicted by a 9:3:3:1 ratio. You calculate a chi square and get a p value of less than 0.0001. Which of the following statements is most accurate based on this observation?

#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?

#Question id: 12001

#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 population has the highest fitness at 25°C ? 

#Question id: 12002

#Unit 10. Ecological Principles

#Question id: 12003

#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.

If all three populations were mixed together and placed at 37°C, which of the following would  be most likely to happen?

#Question id: 12004

#Unit 10. Ecological Principles

The figure above shows the distribution of 10 plant species that grow along a regular environmental gradient, such as depth of the water table in a river valley. All other environmental factors are similar. This figure demonstrates that

#Question id: 12005

#Unit 10. Ecological Principles