Chapter 1 What is Science? 1 1 What Is Science? Key Concept The goal of science is to investigate and understand the natural world, to explain events in the natural world, and to use those explanations to make useful predictions. 1 2 How Scientists Work Whenever possible, a hypothesis should be tested by an experiment in which only one variable is changed at a time. All other variables should be kept unchanged, or controlled. In science, the word theory applies to a well-tested explanation that unifies a broad range of observations. 1 3 Studying Life science observation data hypothesis spontaneous generation controlled experiment independent variable dependent variable theory Living things share characteristics including cellular organization, reproduction, a universal genetic code, growth and development, use of materials and energy, response to their environment, maintaining an internal stability, and, as a group, change over time. Some of the levels at which life can be studied include molecules, cells, organisms, populations of a single kind of organism, communities of populations living in the same area, and the biosphere. At all these levels, smaller living systems are found within larger systems. biology cell sexual reproduction asexual reproduction stimulus homeostasis 1 4 Tools and Procedures Most scientists use the metric system when collecting data and performing experiments. Light microscopes produce magnified images by focusing visible light rays. Electron microscopes produce magnified images by focusing beams of electrons. microscope compound light microscope electron microscope
1. What is the goal of science? Biology 1 Semester Review 2. How does an observation about an object differ from an inference about that object? 3. What is homeostasis? Give an example of how it is maintained. 4. Compare sexual reproduction and asexual reproduction. 5. Why is it advantageous for scientists to test only one variable at a time during an experiment? 6. Distinguish between a variable and a control. 7. What is the main difference between qualitative and quantitative observations? 8. What is a scientific hypothesis? In what two ways can a hypothesis be tested? 9. Is a scientific hypothesis accepted if there is no way to demonstrate that the hypothesis is wrong? Explain your answer. 10. What must happen for a hypothesis to become a theory? 11. What is differentiation? 12. How does a scientific theory compare with a scientific hypothesis? 13. Describe five characteristics of living things. Chapter 2 The Chemistry of Life 2 1 The Nature of Matter The subatomic particles that make up atoms are protons, neutrons, and electrons. Because they have the same number of electrons, all isotopes of an element have the same chemical properties. The main types of chemical bonds are covalent bonds and ionic bonds. 2 2 Properties of Water A water molecule is polar because there is an uneven distribution of electrons between the oxygen and hydrogen atoms. atom electron element isotope compound chemical bond ionic bond ion covalent bond molecule cohesion adhesion mixture solution
Acidic solutions contain higher concentrations of H + ions than solute pure water and have ph values below 7. solvent Basic, or alkaline, solutions contain lower concentrations of H + suspension ions than pure water and have ph values above 7. ph scale acid base 2 3 Carbon Compounds Four groups of organic compounds found in living things are carbohydrates, lipids, nucleic acids, and proteins. Living things use carbohydrates as their main source of energy. Plants and some animals also use carbohydrates for structural purposes. Lipids can be used to store energy. Some lipids are important parts of biological membranes and waterproof coverings. Nucleic acids store and transmit hereditary, or genetic, information. Some proteins control the rate of reactions and regulate cell processes. Some proteins build tissues such as bone and muscle. Others transport materials or help to fight disease. 2 4 Chemical Reactions and Enzymes Chemical reactions always involve the breaking of bonds in reactants and the formation of new bonds in products. Chemical reactions that release energy often occur spontaneously. Chemical reactions that absorb energy will not occur without a source of energy. Enzymes speed up chemical reactions that take place in cells. monomer polymer carbohydrate monosaccharide polysaccharide lipid nucleic acid nucleotide ribonucleic acid (RNA) deoxyribonucleic acid (DNA) protein amino acid chemical reaction reactant product activation energy catalyst enzyme substrate 1. Explain the relationship among atoms, elements, and compounds. 2. Name four groups of organic compounds found in living things. 3. How are atoms in a compound held together? 4. Distinguish among single, double, and triple covalent bonds. 5. Explain the properties of cohesion and adhesion. Give an example of each property. 6. What is the relationship among solutions, solutes, and solvents?
7. Compare acidic and basic solutions in terms of their H + ion and OH ion concentrations. How do their ph values differ? 8. Explain the relationship between monomers and polymers, using polysaccharides as an example. 9. Identify three major roles of proteins. 10. Describe the parts of a nucleotide. 11. Name the two basic kinds of nucleic acids. What sugar does each contain? 12. What is a chemical reaction? Describe the role of energy in chemical reactions 13. What is a covalent bond? An ionic bond? 14. What are enzymes, and how are they important to living things? 15. What is a compound? How are compounds related to molecules? Chapter 7 Cell Structure and Function 7 1 Life Is Cellular The cell theory states that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells. Prokaryotic cells have genetic material that is not contained in a nucleus. Eukaryotic cells contain a nucleus in which their genetic material is separated from the rest of the cell. cell cell theory nucleus eukaryote prokaryote 7 2 Eukaryotic Cell Structure The nucleus contains nearly all the cell's DNA and the coded instructions for making proteins and other important molecules. Proteins are assembled on ribosomes. One type of endoplasmic reticulum makes membranes and secretory proteins. The other type of ER makes lipids and helps to detoxify, or remove harmful substances. The Golgi apparatus modifies, sorts, and packages proteins and other materials from the endoplasmic reticulum for storage or secretion outside the cell. Mitochondria convert the chemical energy stored in food into organelle cytoplasm chromatin chromosome nucleolus ribosome endoplasmic reticulum Golgi apparatus lysosome vacuole mitochondrion chloroplast cytoskeleton
compounds that are more convenient for the cell to use. Chloroplasts capture the energy from sunlight and convert it into chemical energy. The cytoskeleton is a network of protein filaments that helps the cell to maintain its shape. The cytoskeleton is also involved in movement of materials within and outside the cell. centriole 7 3 Cell Boundaries All cells have a cell membrane. The cell membrane regulates what enters and leaves the cell and also provides protection and support. Some cells also have cell walls. Cell walls provide additional support and protection. Diffusion causes many substances to move across a cell membrane but does not require the cell to use energy. Osmosis is the diffusion of water through a selectively permeable membrane. 7 4 The Diversity of Cellular Life cell membrane cell wall lipid bilayer diffusion equilibrium osmosis isotonic hypertonic hypotonic facilitated diffusion active transport endocytosis phagocytosis pinocytosis exocytosis Cells in multicellular organisms develop in different ways to perform particular functions within the organism. The levels of organization in a multicellular organism are individual cells, tissues, organs, and organ systems. cell specialization tissue organ organ system 1. Make a table to summarize the contributions made to the cell theory by Robert Hooke, Matthias Schleiden, Theodor Schwann, and Rudolf Virchow. 2. How are prokaryotic and eukaryotic cells alike? How do they differ? 3. Draw a cell nucleus. Label and give the function of the following structures: chromatin, nucleolus, and nuclear envelope. 4. What is the function of a ribosome?
5. What process takes place in the rough endoplasmic reticulum? 6. Describe the role of the Golgi apparatus. 7. What three statements make up the cell theory? 8. Name and describe the two types of structures that make up the cytoskeleton. 9. Briefly describe the structure of a cell membrane. How does the cell membrane affect the contents of a cell? 10. What is meant by the concentration of a solution? Give a specific example of concentration involving volume and mass. 11. Describe the process of diffusion. Name and describe the condition that exists when the diffusion of a particular substance is complete. 12. What is the relationship between osmosis and diffusion? By definition, what's the only substance that carries out osmosis? 13. Using the example of a cell in a sugar solution, explain what is meant by an isotonic solution. 14. Name and describe the cell structure that helps prevent damage to certain cells when they are subjected to high osmotic pressure. 15. Use an example to describe the relationship among cells, tissues, organs, and organ systems. Chapter 10 Cell Growth and Division 10 1 Cell Growth Key Concept The larger a cell becomes, the more demands the cell places on its DNA. In addition, the cell has more trouble moving enough nutrients and wastes across the cell membrane. cell division 10 2 Cell Division During the cell cycle, a cell grows, prepares for division, and divides to form two daughter cells, each of which then begins the cycle again. Biologists divide the events of mitosis into four phases: prophase, metaphase, anaphase, and telophase. Mitosis insures that each daughter cell has the same genetic information as the parent cell. During prophase in animal cells, the centrioles separate and take up positions on opposite sides of the nucleus. In addition, chromosomes condense and the spindle appears. mitosis cytokinesis chromatid centromere interphase cell cycle prophase centriole spindle metaphase
During metaphase, the chromosomes line up across the center of the cell. Microtubules connect the chromosome to each pole of the spindle. During anaphase, the centromeres that join the sister chromatids split, and the sister chromatids separate and become individual chromosomes. In telophase, the chromosomes, which were distinct and condensed, uncoil and disperse as the nuclear envelope re-forms. Cytokinesis is the division of the cytoplasm. anaphase telophase 10 3 Regulating the Cell Cycle Cyclins regulate the timing of the cell cycle in eukaryotic cells. Cancer cells do not respond to the signals that regulate the growth of most cells. cyclin cancer 1. Summarize what happens during the process of cell division. 2. Explain how a cell's DNA can limit the cell's size. 3. Describe what is meant by each of the following terms: cell volume, cell surface area, ratio of surface area to volume. 4. How is a cell's potential growth affected by its ratio of surface area to volume? 5. Describe how a cell's chromosomes change as a cell prepares to divide. 6. What is the relationship between interphase and cell division? 7. Summarize what happens during interphase. 8. Explain how the following terms are related to one another: DNA, centromere, chromosome, chromatid. 9. List the following events in the correct sequence, and describe what happens during each event: anaphase, metaphase, prophase, and telophase. 10. How does the number of chromosomes in the two new cells compare with the number in the original cell at the end of cell division? 11. Summarize what happens during the cell cycle. 12. When some cells are removed from the center of a tissue culture, will new cells replace the cells that were removed? Explain. 13. Describe the role of cyclins in the cell cycle. 14. Why is it important that cell growth in a multicellular organism be regulated so carefully? 15. How do cancer cells differ from noncancerous cells? How are they similar?
Chapter 11 Introduction to Genetics 11 1 The Work of Gregor Mendel The principle of dominance states that some alleles are dominant and others are recessive. When each F 1 plant flowers, the two alleles segregate from each other so that each gamete carries only a single copy of each gene. Therefore, each F 1 plant produces two types of gametes those with the allele for tallness and those with the allele for shortness. 11 2 Probability and Punnett Squares genetics fertilization true-breeding trait hybrid gene allele segregation gamete The principles of probability can be used to predict the outcomes of genetic crosses. Punnett squares can be used to predict and compare the genetic variations that will result from a cross. 11 3 Exploring Mendelian Genetics probability Punnett square homozygous heterozygous phenotype genotype The principle of independent assortment states that genes for different traits can segregate independently during the formation of gametes. Independent assortment helps account for the many genetic variations observed in plants, animals, and other organisms. Some alleles are neither dominant nor recessive, and many traits are controlled by multiple alleles or multiple genes. independent assortment incomplete dominance codominance multiple alleles polygenic trait 11 4 Meiosis Meiosis is a process of reduction division in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell. Mitosis results in the production of two genetically identical diploid cells, whereas meiosis produces four genetically different haploid cells. homologous diploid haploid meiosis tetrad crossingover
11 5 Linkage and Gene Maps Key Concept Chromosomes assort independently; individual genes do not. gene map 1. List the four basic principles of genetics that Mendel discovered in his experiments. Briefly describe each of these principles. 2. What is probability? How does probability relate to genetics? 3. In pea plants, the allele for yellow seeds is dominant to the allele for green seeds. Predict the genotypic ratio of offspring produced by crossing two parents heterozygous for this trait. Draw a Punnett square to illustrate your prediction. 4. How do multiple alleles and polygenic traits differ? 5. Why can multiple alleles provide many different phenotypes for a trait? 6. Are an organism's characteristics determined only by its genes? Explain. 7. Suppose that for an organism, 2N = 8. How many chromosomes do the organism's gametes contain? 8. In rabbits, B is an allele for black coat and b is an allele for brown coat. Write the genotypes for a rabbit that is homozygous for black coat and another rabbit that is heterozygous for black coat. 9. Describe the process of meiosis. 10. Compare the phases of meiosis I with the phases of meiosis II in terms of the number and arrangement of the chromosomes. 11. Explain why it is chromosomes, not individual genes, that assort independently. Chapter 14 The Human Genome 14 1 Human Heredity All human egg cells carry a single X chromosome (23,X). However, half of all sperm cells carry an X chromosome (23,X) and half carry a Y chromosome (23,Y). This ensures that just about half of the zygotes will be 46,XX (female), and half will be 46,XY (male). karyotype sex chromosome autosome pedigree In both cystic fibrosis and sickle cell disease, a small change in the DNA of a single gene affects the structure of a protein, causing a serious genetic disorder.
14 2 Human Chromosomes Males have just one X chromosome. Thus, all X-linked alleles are expressed in males, even if they are recessive. sex-linked gene nondisjunction If nondisjunction occurs, abnormal numbers of chromosomes may find their way into gametes, and a disorder of chromosome numbers may result. 1. Describe how a karyotype is prepared and analyzed. 2. What is the difference between autosomes and sex chromosomes? 3. How can a family pedigree be helpful in determining the probability of having a child with a genetic disorder? 4. In the pedigree below, the shaded symbols indicate people who have hemophilia. Which mothers certainly are carriers? Why did the sons of person 3 not inherit the trait? 5. Is it possible for a person with blood type alleles I A and I B to have blood type A? Explain your answer. 6. Explain the significance of the Rh factor in blood groups. 7. Why are sex-linked disorders more common in males than in females? 8. What determines whether an allele is dominant, recessive, or codominant? 9. What is a chromosomal disorder? Name one chromosomal disorder that can result from nondisjunction. 20. Using an example, explain how a small change in a person's DNA can cause a genetic disorder. 21.. Why are sex-linked disorders more common in males than in females? 22. How does nondisjunction cause chromosome number disorders?