INTRODUCTION TO CELLSUnity and Diversity of CellsCells Under the MicroscopeCHAPTER 1INTRODUCTION TO CELLS 2009 Garland Science PublishingUnity and Diversity of Cells1-1 Living systems are incredibly diverse in size, shape, environment, and behavior. It is estimated that there are between 10 million and 100 million different species. Despite thiswide variety of organisms, it remains difficult to define what it means to say something isalive. Which of the following can be described as the smallest living unit?(a) DNA(b) cell(c) organelle(d) protein1-2 Indicate whether the following statements are true or false. If the statement is false, explain why it is false.A. A virus is a living organism.B. Cells of different types can have different chemical requirements.C. A human white blood cell is larger than a Paramecium cell.1-3 For each of the following sentences, fill in the blanks with the best word or phrase selected from the list below. Not all words or phrases will be used; each word or phrase should be used only once.Cells can be very diverse: superficially, they come in various sizes, ranging from bacterial cells such as Lactobacillus, which is a few __________________ in length, to larger cells such as a frog’s egg, whichhas a diameter of about one __________________. Despite the diversity, cells resemble each other to an astonishing degree in their chemistry. For example, the same 20 __________________ are used to make proteins. Similarly, the genetic information of all cells is stored in their __________________. Although __________________ contain the same type of molecules as cells, their inability to reproduce themselves by their own efforts means that they are not considered living matter.amino acids micrometer(s) virusesDNA millimeter(s) yeastfatty acids plantsmeter plasma membranes1-4 The flow of genetic information is controlled by a series of biochemical reactions that result in the production of proteins, each with its own specific order of amino acids. Choose the correct series biochemical reactions from the options presented here.(a) replication, transcription, translation(b) replication, translation, transcription(c) translation, transcription, replication(d) translation, replication, transcription1-5 Proteins are important architectural and catalytic components within the cell, helping to determine its chemistry, its shape, and its ability to respond to changes in the environment. Remarkably, all of the different proteins in a cell are made from the same 20 __________. By linking them in different sequences, the cell can make protein molecules with different conformations and surface chemistries, and therefore different functions.(a) nucleotides(b) sugars(c) amino acids(d) fatty acids1-6 Changes in DNA sequence from one generation to the next may result in offspring that are altered in fitness compared with their parents. The process of change and selection over the course of many generations is the basis of __________.(a) mutation(b) evolution(c) heredity(d) reproductionCells Under the Microscope1-7 What unit of length would you generally use to measure a typical human cell?(a) centimeters(b) nanometers(c) millimeters(d) micrometers1-8 Match the type of microscopy on the left with the corresponding description provided below. There is one best match for each.A. confocalB. transmission electronC. fluorescenceD. phase contrastE. scanning electronF. bright-field____ uses a light microscope with an optical component to take advantage of the differentrefractive indexes of light passing through different regions of the cell.____ employs a light microscope and requires that samples be fixed and stained in order to reveal cellular details.____ requires the use of two sets of filters. The first filter narrows the wavelength range that reaches the specimen and the second blocks out all wavelengths that pass back up to the eyepiece except for those emitted by the dye in the sample.____ scans the specimen with a focused laser beam to obtain a series of two-dimensional optical sections, which can be used to reconstruct an image of the specimen in three-dimensions. The laser excites a fluorescent dye molecule, and the emitted light from each illuminated point is captured through a pinhole and recorded by a detector.____ has the ability to resolve cellular components a small as 2 nm.____ requires coating the sample with a thin layer of a heavy metal to produce three-dimensional images of the surface of a sample.1-9 Cell biologists employ targeted fluorescent dyes or modified fluorescent proteins in both standard fluorescence microscopy and confocal microscopy to observe specific details in the cell. Even though fluorescence permits better visualization, the resolving power is essentially the same as that of a standard light microscope because the resolving power ofa microscope is limited by the __________ of light.(a) absorption(b) intensity(c) filtering(d) wavelengthThe Procaryotic Cell1-10 By definition, procaryotic cells do not possess __________.(a) a nucleus(b) replication machinery(c) ribosomes(d) membrane bilayers1-11 Although there are many distinct procaryotic species, most have a small range of shapes, sizes, and growth rates. Which of the following characteristics are not observed in procaryotes?(a) a highly structured cytoplasm(b) endoplasmic reticulum(c) the ability to divide rapidly(d) a cell wall1-12 Indicate whether the following statements are true or false. If the statement is false, explain why it is false.A. Oxygen is toxic to certain procaryotic organisms.B. Mitochondria are thought to have evolved from anaerobic bacteria.C. Although bacteria use a variety of organic substances as food, bacteria are not able live on inorganic substances.The Eucaryotic Cell1-13 Use the list of structures below to label the schematic drawing of an animal cell in Figure Q1-13.A. plasma membraneB. nuclear envelopeC. cytosolD. Golgi apparatusE. endoplasmic reticulumF. mitochondrionG. transport vesiclesFigure Q1-131-14 For each of the following sentences, fill in the blanks with the best word or phrase selected from the list below. Not all words or phrases will be used; each word or phrase should be used only once.Eucaryotic cells are bigger and more elaborate than procaryotic cells. By definition, all eucaryotic cells have a __________________, usually the most prominent organelle. Another organelle found in essentially all eucaryotic cells is the __________________,