LEARNING OBJECTIVES In this section, you will explore the following questions: Connection for AP® Courses We commonly think of pathogens when we think of prokaryotes, focusing on their relationship with disease. However, most prokaryotes do not cause disease and they play…
LEARNING OBJECTIVES In this section, you will explore the following questions: Connection for AP® Courses Although many bacteria participate in mutualistic relationships with their hosts, others exist in parasitic relationships, causing disease. Many bacteria have evolved resistance to antibiotics, and scientists…
LEARNING OBJECTIVES In this section, you will explore the following questions: Connection for AP® Courses Because prokaryotes are metabolically diverse organisms, they can flourish in many different environments using a wide range of energy and carbon sources. Some are decomposers that…
LEARNING OBJECTIVES In this section, you will explore the following questions: Connection for AP® Courses Domains Archaea and Bacteria contain single-celled organisms lacking a nucleus and other membrane-bound organelles. The two groups have substantial biochemical and structural differences. Most have a…
LEARNING OBJECTIVES In this section, you will explore the following questions: Connection for AP® Courses In the recent past, scientists grouped living organisms into five kingdoms based on several criteria, including the absence or presence of a nucleus and other membrane-bound…
Figure 22.1 Certain prokaryotes can live in extreme environments such as the Morning Glory pool, a hot spring in Yellowstone National Park. The spring’s vivid blue color is from the prokaryotes that thrive in its very hot waters. (credit: modification of work…
Viral Evolution, Morphology, and Classification Viruses are tiny, acellular entities that can usually only be seen with an electron microscope. Their genomes contain either DNA or RNA—never both—and they replicate using the replication proteins of a host cell. Viruses are…
LEARNING OBJECTIVES In this section, you will explore the following questions: Connection for AP® Courses The content described in this section is outside the scope for AP®. However, it’s interesting to note that prions and viroids—pathogens that are far simpler in…
LEARNING OBJECTIVES In this section, you will explore the following questions: Connection for AP® Courses The majority of content described in this section is not within the scope for AP®. We explore some of these concepts when we study the immune…
LEARNING OBJECTIVES In this section, you will explore the following questions: Connection for AP® Courses Viruses differ from other organisms in their method of replication. Viruses replicate within a living host cell, producing changes in the cell that often result in…