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Over the years, scientists have wondered how many cells are in the human body. They don't yet agree, but 10 trillion seems a reasonable estimate. There is a consensus, however, that there are at least 10 times as many prokaryotic cells associated with the body, residing in a community called the microbiome. We each host a unique community consisting of about 3 pounds (1.4 kilograms) of prokaryotic life, which includes roughly 100 different types of bacteria. These cells colonize the nose, skin, vagina, and the digestive tract from mouth to anus.
Because the digestive tract is a tube open to the outside at both ends, our microbiome occupies a unique niche that is simultaneously integral to—yet outside of—our bodies. With recent advances allowing identification of microorganisms by their unique DMA sequences, scientists are increasingly studying our relationships with our microbial residents. Our gut microbiome helps digest food and synthesize vitamins, and it allows the immune system to develop properly. Even though our bacterial populations changes in response to food intake and states of disease and health, one thing is clear: We would not be ourselves without them.
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Biology
- Which of the following statements is true? a) cells do not need ribosomes if they have mitochondriab) all cells have a cell membrane but not all cells have a cell wallc) all prokaryotes are unicellular and all eukaryotes are multicellulard) cells can have either a cell membrane or a cell wall or botharrow_forwardDescribe the three major domains of life: Archaea, Bacteria, and Eukarya. Explain what the three domains have in common and how they differ. Define viruses, and explain how they relate to living cells. Explain how microbial diseases have changed human history. Explain the tenets of Cell Theory Describe how microscopy led to the Germ Theory of infectious disease Define the germ theory of disease. Explain how Koch's postulates can show that a specific kind of microbe causes a disease. Explain the problems in interpreting Koch's postulates in practice.arrow_forward(if anyone please help me with all these questions) 2. As eukaryotic cells become more specialized, the nucleus is NOT important as the site of a) DNA synthesis, b) changes in the regulation of genes, c) protein synthesis, d) the transcription of mRNA for protein synthesis, e) DNA mutation. 3. In the evolution of the eukaryotic cell, these cells have key changes that include which of the following: a) These cells reproduce by copying their DNA perfectly each generation. b) They have their DNA in the nucleoid area. c) have adapted the mesosome membrane system of the prokaryote to form a nucleus and an endoplasmic reticulum. d) each new type on new eukaryote cell has its own mesosomes e) none of these are true. 4. The evolution/development of the skeletal system found in the Deuterostomes, is made up of two molecules, Ca+2PO4-2 and collagen These molecules are produced released from by a specialized type of stem cell. Therefore, one would expect that these stem cells perform which…arrow_forward
- In the domain system of classification, prokaryotes are divided into two domains: Bacteria and Archaea. The two domains differ in all BUT one feature. Which feature do they have in common? Question options: They both have identical cell walls. They both have prokaryotic cells. They both thrive in extreme environments. They both are able to live only under anaerobic conditions.arrow_forwardWhich of the following describe prokaryotes? a) usually have a circular chromosome b) typically have multiple chromosomes c) are usually diploid d) none of the abovearrow_forwarda) Describe some characteristics and differences between prokaryotic and eukaryotic cells.b) How do the three domains of life differ from one another?c) Two of the organelles in eukaryotes, the mitochondrion and the chloroplast are believed to haveoriginated through a process of symbiosis. Discuss some of the theories of the origins ofmitochondria and chloroplastsarrow_forward
- Which of the following is considered a distinguishing characteristic of prokaryotic cells? a) They generally reproduce by binary fission. b) They possess a nucleus. c) They generally possess linear chromosomes. d) All of the above are true regarding most prokaryotes. e) None of the above are true.arrow_forwardIn comparing bacteria, archaea, and eukaryotes, which statement below among A - D is false? A) O the members of two of these three groups comprise cells that lack a nuclear membrane B) O archaea and eukaryotes share some similarities in the componeents of gene expression C) O having diverse types of metabolism is a feature of the members of archaea and bacteria D) Oa cytoplasmic membrane is a feature shared by all the cells in these three groups E) OA-E are all truearrow_forwardWhich of the following descriptions is true only of prokaryotes? (a) They reproduce through binary fission. (b) Their genetic material is DNA. (c) They are unicellular. (d) They contain organelles within the cell. (e) none of the abovearrow_forward
- If all prokaryotes were eliminated from the planeta) animals would thrive because there would be no disease.b) archaea would thrive because there would be no competition for nutrients.c) all animals would die.d) animals and archaea would thrive.arrow_forwardWhy do some microbiologists disagree with classifying bacteria and archaea as “prokaryotes”?arrow_forwardSome prokaryotes, especially archaea, are capable of living in extreme environments, such as deep-sea vents, where temperatures can reach 80°C (176°F). Few organisms can survive at this temperature. What adaptations might archaea possess that allow them to survive in such extreme heat?arrow_forward
- Biology Today and Tomorrow without Physiology (Mi...BiologyISBN:9781305117396Author:Cecie Starr, Christine Evers, Lisa StarrPublisher:Cengage Learning