Which of the following statements is true about the Krebs (citric acid) cycle and the Calvin (light-independent) cycle?

Individuals of a particular species of ground beetle are either light tan or dark brown. Light-tan beetles are predominant in habitats with light-colored sandy soils, and dark brown beetles are predominant in habitats with dark-colored loam soils. In an experiment designed to determine the survival rates of light-tan beetles and dark brown beetles in different habitats, 500 light-tan beetles and 500 dark-brown beetles were released in each of four habitats. Each beetle had been marked with a small spot of red paint on the underside of its abdomen before it was released. One week after the beetles had been released, any marked beetles that could be found were recaptured. The results are presented in the table below. It is assumed that differences in the numbers of beetles recaptured are directly related to differences in survival rates. Which of the following can be inferred from the data in the table?

Using the diagram below of the adult human heart, the correct sequence of blood flow beginning at the pulmonary arteries and passing through the lungs and the systemic circulation is

Individuals of a particular species of ground beetle are either light tan or dark brown. Light-tan beetles are predominant in habitats with light-colored sandy soils, and dark brown beetles are predominant in habitats with dark-colored loam soils. In an experiment designed to determine the survival rates of light-tan beetles and dark brown beetles in different habitats, 500 light-tan beetles and 500 dark-brown beetles were released in each of four habitats. Each beetle had been marked with a small spot of red paint on the underside of its abdomen before it was released. One week after the beetles had been released, any marked beetles that could be found were recaptured. The results are presented in the table below. It is assumed that differences in the numbers of beetles recaptured are directly related to differences in survival rates. If all insectivorous birds and remaining beetles were removed from habitat 2 and 500 additional dark-brown beetles and 500 additional light-tan beetles were then released into habitat 2, which of the following is the best estimate of the number of additional dark brown beetles that would be expected to be recaptured in habitat 2 after one more week?

What proportion of the population is heterozygous (Bb) for this trait?

Once transcribed, eukaryotic mRNA typically undergoes substantial alteration that results primarily from

A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 49 percent of the animals display a recessive trait (bb), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants. What is the frequency of allele b in the gene pool?

Each set of lettered choices below refers to the numbered words or statements immediately following it. Select the one lettered choice that best fits each word or statement. A choice may be used once, more than once, or not at all in each set. Members of which species are herbivores?

This question refers to an experiment that is set up to determine the relative volume of O2 consumed by germinating and nongerminating (dry) pea seeds at two different temperatures. The change in volume is detected by using a respirometer over a given period of time. The data are given below.The rate of oxygen consumption in germinating pea seeds at 26°C is

According to fossil records and recent published observations, two species of leaf eating beetles (species A and B) have existed on an isolated island in the Pacific Ocean for over 100,000 years. In 1964 a third species of leaf-eating beetle (species C) was accidentally introduced on the island. The population size of each species has been regularly monitored as shown in the graph above. Propose an explanation for the pattern of population density observed in species C. Describe the effect that the introduction of beetle species C has had on the population density of species A and species B. Propose an explanation for the patterns of population density observed in species A and in species B. Predict the population density of species C in 2014. Provide a biological explanation for your prediction. Explain why invasive species are often successful in colonizing new habitats.