Figure 14.1 Plants dominate the landscape and play an integral role in human societies. (a) Palm trees grow in tropical or subtropical climates; (b) wheat is a crop in most of the world; the flower of (c) the cotton plant produces fibers…
Prokaryotic Diversity Prokaryotes existed for billions of years before plants and animals appeared. Microbial mats are thought to represent the earliest forms of life on Earth, and there is fossil evidence, called stromatolites, of their presence about 3.5 billion years…
Learning Objectives By the end of this section, you will be able to: Figure 13.20 The (a) familiar mushroom is only one type of fungus. The brightly colored fruiting bodies of this (b) coral fungus are displayed. This (c) electron micrograph shows…
Learning Objectives By the end of this section, you will be able to: Figure 13.13 Protists range from the microscopic, single-celled (a) Acanthocystis turfacea and the (b) ciliate Tetrahymena thermophila to the enormous, multicellular (c) kelps (Chromalveolata) that extend for hundreds of feet in underwater “forests.”…
Learning Objectives By the end of this section, you will be able to: The fossil record and genetic evidence suggest that prokaryotic cells were the first organisms on Earth. These cells originated approximately 3.5 billion years ago, which was about…
Learning Objectives By the end of this section, you will be able to: Prokaryotes are present everywhere. They cover every imaginable surface where there is sufficient moisture, and they live on and inside of other living things. There are more…
Figure 13.1 Living things are very diverse, from simple, single-celled bacteria to complex, multicellular organisms. (credit “ringworm”: modification of work by Dr. Lucille K. Georg, CDC; credit “Trypanosomes”: modification of work by Dr. Myron G. Schultz, CDC; credit “tree mold”: modification of…
Organizing Life on Earth Scientists continually obtain new information that helps to understand the evolutionary history of life on Earth. Each group of organisms went through its own evolutionary journey, called its phylogeny. Each organism shares relatedness with others, and…
Learning Objectives By the end of this section, you will be able to: Scientists collect information that allows them to make evolutionary connections between organisms. Similar to detective work, scientists must use evidence to uncover the facts. In the case…
Learning Objectives By the end of this section, you will be able to: All life on Earth evolved from a common ancestor. Biologists map how organisms are related by constructing phylogenetic trees. In other words, a “tree of life” can…