Variations in a population of moths allow for some of its members to be able to adapt to environmental changes.

1.Variations in a population of moths allow for some of its members to be able to adapt to environmental changes. The better adapted of the moths will be able to survive the change and thus prevail as the "fittest" of the species. (a) Describe three mechanisms in which variation can occur within a species population. (b) Explain which mechanism or mechanisms would be responsible for the survival of a population of peppered moths better than white moths in an environment affected by industrial soot. Justify your answer.

2. A photo-absorption experiment was conducted in the lab to determine the best suitable light to drive photosynthesis in the cell. During the experiment, white light was separated into colors (wavelengths) using a prism. Each color was then passed through a sample of chlorophyll (the light-absorbing molecule found in plants. Using a photoelectric tube, the light energy was converted into electricity and recorded by a galvanometer. (a) Using the colors of the light spectrum, predict which colors were most effective in driving photosynthesis. (b) Based on your answer in part (a), describe the relationship between wavelength and energy.

3. Most organisms, whether aquatic or terrestrial, must balance water movement between their internal and external environments in order to maintain homeostasis. Although quite complex in their mechanisms, both fish and humans have excretory systems that produce fluid liquid waste (urine). (a) Explain four fundamental steps that are common in most excretory processes. (b) Discuss how the terrestrial adaption of animals led to more advanced and complex kidneys.

4. Asexual reproduction is the creation of a new individual whose genes all come from one parent without the fusion of egg and sperm, in most cases, it relies entirely on mitotic cell division. (a) Identify three mechanisms of asexual reproduction, and then (b) explain some advantages of reproducing asexually. Why would these be considered an advantage over sexual reproduction? Justify your answer.

5. RNA viruses lack replication error-checking mechanisms, and thus have higher rates of genetic variation. Discuss the importance of error-checking mechanisms during replication and how in the absence of these mechanisms genetic variation is introduced.

6. A chloroplast is a specialized organelle that conducts photosynthesis. Its compartmentalized structure supports its function. (a) Describe two examples in which chloroplasts and their subcellular structures help to provide essentials for members of their biosphere. (b) In a scientific study, scientists insert chloroplasts into an animal cell by regulating its lysosomal activity. How would advancements in this study benefit animals?

7. To accomplish regulation in prokaryotes, operons (segments of DNA) include specialized regions where a variety of regulatory proteins bind and detach to either initiate or inhibit transcription of the genes on that segment. (a) Identify two of the proteins involved in the gene regulation in prokaryotes and their function. (b) Describe the properties of the repressor that demonstrate it to be a protein. (c) Discuss the evidence that proves it to be a repressor within the operon. (d) Compare and contrast the roles of a repressor in an inducible system vs. its role in a repressible system.

8. Membrane-bound receptors are an important component facilitating some types of cellular communication; however, not all signal-receptor binding occurs outside the cell membrane. Some signal molecules are able to pass through the plasma membrane, and their receptors are intracellular. In a theoretical lab study, scientists work to design a lab experiment that would inhibit some molecules' ability to bind with their intracellular receptors. (a) Draw conclusions about the structure and function of membrane proteins. (b) Identify some molecules that are able to pass through the plasma membrane to bind with their intracellular receptors. (c) Explain what needs to be the focus of the scientists' study in order to inhibit signal molecules from reaching and binding to their intracellular receptors and thereby enabling the signal transduction pathway. Justify your answer. (d) Discuss how the inhibition of these molecules will affect protein production.