When a mother herring gull returns to its nest, its chicks (young offspring) will peck at its beak. Scientists believed that this pecking behavior is a fixed action pattern. In an experiment to determine the sign stimulus of this behavior, scientists made cardboard cutouts of gull heads with different appearances, presented them to the chicks, and recorded the number of times that the chicks pecked at the cutout. The following graph shows the results of this experiment. The gull head on the far left was the control (or, what an actual gull head looks like). Values on this graph represent the percentage of time that gull chicks pecked at each cutout relative to the control. Based on the results of this experiment, what is the most likely sign stimulus for this behavior?  

While on the Beagle, Darwin noted that animals and plants on islands were different from, but closely related to, similar forms found on the nearest continent.  What did this tell Darwin?

Lipid-soluble chemicals such as DDT

Which of the following statements is NOT true? FYI: T3 and T4 are amines; water soluble hormonesTSH – Thyroid-stimulating hormoneTRH – Thyroid-releasing hormone

Which of the following is a TRUE statement regarding dispersion patterns within a population?

Prior to the arrival of Europeans, North American prairies were habitat for millions of greater prairie chickens. In Illinois alone, their numbers plummeted from about 100 million birds in 1900 to about 50 birds in the 1990s. The declines in population resulted from hunting and habitat destruction.  This scenario is an example of Select all correct choices.  

Which of the following is an accurate statement about hormones? Select all correct choices.

A volcano in the Galapagos is home to two forms of iguana, a pink iguana (Conolophus marthae), and a yellow iguana (Conolophus subcristatus).  C. marthae and C. subcristatus diverged from each other (speciation occurred) 5.7 million years ago.  Based on what you learned in class about the biological species concept, this means that  [species] Iguanas produce femoral pore secretions from a gland on their back legs.  C. marthae and C. subcritatus have very different chemical signals released from their femoral pores.  The fact that the species produces different chemical mating signals serves as a [3]    

The following image shows the phylogenetic tree of organisms that evolved around the time of the Cambrian Radiation. Choose the most accurate statement about this tree: 

A small farm pond was stocked with 50 muskies earlier this spring. Because there were no other fish in the pond, the populations grew rapidly. If the rate of increase for these fish was 0.40, how many individuals were present in the population after one generation?