Chapter 2 Vocabulary

generalist

A generalist is an organism that can thrive in a wide variety of environmental conditions and make use of a variety of different resources, such as consuming many different types of food.

Chapter review

1. What are the seven traits of life? 2. A scientist is exploring in a remote area with many unidentified species. They find an unknown object that does not appear to be living. What is one way they could tell whether it is a dead organism that was once alive, versus an inanimate object that was never living? 3. Cows are dependent on bacteria living in their digestive systems to help break down cellulose in the plant material that the cows eat. Explain what characteristics these bacteria must have to be considered living organisms themselves, and not just part of the cow. 4. What is the basic unit of structure and function in living things? 5. Give one example of homeostasis that occurs in humans. 6. Can a living thing exist without using energy? Why or why not? 7. True or False. Evolution is a change in the characteristics of living things over time. 8. True or False. Only some living things have genes. 9. Give an example of a response to stimuli that occurs in a unicellular organism. 10. A scientist discovers two types of similar-looking insects that have not been previously identified. Answer the following questions about this discovery. A. What is one way they can try to determine whether the two types are the same species? B. If they are not the same species, what are some ways they can try to determine how closely related they are to each other? C. What is the name for a type of diagram they can create to demonstrate their evolutionary relationship to each other and to other insects? D. If they determine that the two types are different species but the same genus, create your own names for them using binomial nomenclature. You can be creative and make up the genus and species names, but be sure to put them in the format of binomial nomenclature. E. If they are the same species but have different colors, what kind of biodiversity does this most likely reflect? F. If they are the same species, but one type of insect has a better sense of smell for their limited food source than the other type, what do you think will happen over time? Assume the insects will experience natural selection. 11. Put the following taxa in order from the most specific to the most inclusive: phylum; species; kingdom; genus; family; domain; class; order 12. Humans are in the which domain? 13. Monkeys, apes, and humans are all in the: A. Same genus B. Same order C. Same class D. Both B and C 14. Amphibians, such as frogs, have a backbone but no hair. What is the most specific taxon that they share with humans? 15. Arboreal means: A. Living on the ground B. Living in the ocean C. Living in trees D. Living on grasslands 16. What is one characteristic of extinct Homo species that was larger than that of modern humans? 17. What is one characteristic of modern humans that is larger than that of extinct Homospecies? 18. True or False. Most primates live in social groups. 19. True or False. Most other mammals have longer lifespans than primates. 20. True or False. Archaea are classified into the Bacteria domain. 21. How is the long period of dependency of infants on adults in primates related to learning? 22. Name one type of primate in the hominid family, other than humans. 23. Why do you think that scientists compare the bones of structures (such as the feet) of extinct Homo species to ours? 24. Some mammals other than primates also have their eyes placed in the front of their face, such as cats. How do you think the vision of a cat compares to that of a mouse, where the eyes are placed more at the sides? 25. Living sponges are animals. Are we in the same kingdom as sponges? Explain your answer.

How are bacteria, yeast: a fungus, and humans classified?

Although yeast are single-celled organisms, they possess a cellular organization similar to that of higher organisms, including humans. Specifically, their genetic content is contained within a nucleus. This classifies them as eukaryotic organisms, unlike their single-celled counterparts, bacteria, which do not have a nucleus and are considered prokaryotes.

Biodiversity

Biological diversity, or biodiversity, refers to all of the variety of life that exists on Earth. Biodiversity can be described and measured at three different levels: species, genetic, and ecosystem diversity.

Within the hominid family, our species is placed in the genus ______Our species, Homo sapiens, is the only living species in this genus. Several earlier species of Homo existed but have since gone extinct, including the species Homo erectus

Homo

primate

Living members of the primate order include monkeys, apes, and humans; and any member of this order of mammals

Myth: Viruses are living things.

Reality: The traditional scientific view of viruses is that they originated from bits of DNA or RNA that were shed from the cells of living things but that they are not living things themselves.

homeostasis

The condition in which a system is maintained in a more-or-less steady state

Why can stopping antibiotics early cause the development of antibiotic-resistant bacteria?

The doctor prescribes an antibiotic to kill the bacteria and advises Wajiha to take the full course of the treatment even if she is feeling better earlier because stopping early can cause an increase in bacteria that are resistant to antibiotic

domain

The domain is a taxon that is larger and more inclusive than the kingdom. Most biologists agree that there are three domains of life on Earth: Bacteria, Archaea, and Eukarya

species

The formal biological definition of species is a group of actually or potentially interbreeding organisms. This means that members of the same species are similar enough to each other to produce fertile offspring together. By this definition of species, all human beings alive today belong to one species, Homo sapiens. All humans can potentially interbreed with each other but not with members of any other species.

taxonomy

The science of classifying organisms is called taxonomy. Classification is an important step in understanding the present diversity and past evolutionary history of life on Earth.

Chapter 2 summary

To be classified as a living thing, most scientists agree that an object must exhibit seven characteristics, including: >Maintaining a more-or-less constant internal environment, which is called homeostasis. >Having multiple levels of the organization and consisting of one or more cells. >Using energy and being capable of metabolism. The ability to grow and develop. >The ability to evolve adaptations to the environment. >The ability to detect and respond to environmental stimuli. >The ability to reproduce, which is the process by which living things give rise to offspring -Biodiversity refers to the variety of life that exists on Earth. It includes species diversity, genetic diversity within species, and ecosystem diversity. -The formal biological definition of species is a group of actually or potentially interbreeding organisms. In reality, organisms are often classified into species on the basis of morphology. -A system for classifying living things was introduced by Linnaeus in the 1700s. It includes taxa from the species (least inclusive) to the kingdom (most inclusive). Linnaeus also introduced a system of naming species, called binomial nomenclature -The domain, a taxon higher than the kingdom, was later added to the Linnaean system. Living things are generally grouped into three domains: Bacteria, Archaea, and Eukarya. Humans and other animal species are placed in the Eukarya domain.

(2:2) What do single-celled organisms, such as the bacteria and yeast living in and on Wajiha, have in common with humans?

Wajiha she has strep throat, which is caused by the bacteria Streptococcus pyogenes. doctor prescribes an antibiotic to kill the bacteria. She develops yeast infection. The doctor prescribes an antifungal medication for Wajiha's yeast infection. Our bodies contain a delicate balance of inhabitants that are invisible without a microscope, and changes in that balance can cause unpleasant health effect

Living things can transform energy by converting chemicals and energy into cellular components. This form of metabolism is called _______________.

anabolism

They can also break down, or decompose, organic matter, which is called _________. Living things require energy to maintain internal conditions (homeostasis), for growth, and other life processes.

catabolsim

phylogeny

evolutionary history of a group of related organisms. It is represented by a phylogenetic tree, or some other tree-like diagram, like the one in Figure for the three domains.

Who are our closest relatives in the primate order? We are placed in the family called Hominidae. Any member of this family is called a ________.

hominid. Hominids include four living genera: chimpanzees, gorillas, orangutans, and humans.

evolution

is a change in the allele frequencies and makeup of the populations over time. It comes about through the process of natural selection.

An adaptation

is a characteristic of populations. Individuals of a population carry a variety of genes. When the environment changes, some individuals of the population can withstand the changed conditions and reproduce more than the individuals who cannot live in the given environment.

A cell

is the basic unit of the structure and function of living things. they are the building blocks of living organisms. An average adult human being, for example, consists of trillions of cells.

Reproduction

is the process by which living things give rise to offspring. Reproduction may be as simple as a single cell dividing into two cells. This is how bacteria reproduce. Reproduction in human beings and many other organisms is much more complicated.

All living things can use energy. Their cells have the "machinery" of ______________ which is the building up and breaking down of chemical compounds.

metabolism

binomial nomenclature

naming species. This method, called binomial nomenclature, gives each species a unique, two-word Latin name consisting of the genus name followed by a specific species identifier. An example is Homo sapiens, the two-word Latin name for humans. It literally means "wise human." This is a reference to our big brains.

Morphology

refers to the form and structure of organisms. For classification purposes, it generally refers to relatively obvious physical traits. Typically, the more similar to one another different organisms appear, the greater the chance that they will be classified in the same species.

Human biology

scientific study of human species that includes the fascinating story of human evolution and a detailed accounting of our genetics, anatomy, physiology, and ecology. In short, human biology focuses on how we got here, how we function, and the role we play in the natural world.

A phylogenetic tree

shows how closely related different groups of organisms are to one another. Each branching point represents a common ancestor of the branching groups. Figure , for example, shows that the Eukarya shared a more recent common ancestor with the Archaea than they did with the Bacteria. This is based on comparisons of important similarities and differences between the three domains.

(2:3) What is binomial nomenclature? Give an example.

→ →example:

The SEVEN traits shared by all living things include:

→ maintenance of a more-or-less constant internal environment, (homeostasis) →multiple levels of organization consisting of one or more cells →using energy and exhibiting metabolism → ability to grow and develop → ability to evolve adaptations to the environment →ability to detect and respond to environmental stimuli →ability to reproduce.

(2:3). Explain why it is important to classify living things and outline the Linnaean system of classification.

→It helps make sense of the overwhelming diversity of living things.

The diversity of life, includes:

→different kinds of biodiversity → definition of a species →classification and naming systems for living organisms →how evolutionary relationships can be represented through diagrams such as phylogenetic trees.

(2:3) Define biological species. Why is this definition often difficult to apply?

→formal biological definition of species is a group of actually or potentially interbreeding organisms. →When studying extinct species represented by fossils, it is usually impossible to know whether different organisms could interbreed. Therefore, in practice, many biologists and virtually all paleontologists generally define species on the basis of morphology, rather than breeding behavior.

(2:3) What is biodiversity? Identify three ways that biodiversity may be measured.

→refers to all of the variety of life that exists on Earth. →can be described and measured at three different levels: species, genetic, and ecosystem diversity.