Science Cell Biology PDF

細胞（Cell）是生物體的基本結構和功能單位，所有生物體都是由細胞組成的。細胞不僅能進行基 本的生物過程，如新陳代謝、能量轉換和增殖，還能對環境變化作出反應。以下是細胞的一些主 要特徵和類型： Cell: A cell is the basic structural and functional unit of all living organisms. Every organism is made up of ce...

細胞（Cell）是生物體的基本結構和功能單位，所有生物體都是由細胞組成的。細胞不僅能進行基 本的生物過程，如新陳代謝、能量轉換和增殖，還能對環境變化作出反應。以下是細胞的一些主 要特徵和類型： Cell: A cell is the basic structural and functional unit of all living organisms. Every organism is made up of cells, which perform essential biological processes such as metabolism, energy conversion, and reproduction. Here’s an overview of the key features and types of cells Organelle細胞器 : is a subcellular structure that has one or more specific jobs to perform in the cell, much like an organ does in.細胞內部的一種亞細胞結構，具有一個或 多個特定的功能，類似於器官在身體中的作用。 1. Basic Structure of Cells （ 細胞的基本結構） Cell Membrane 細胞膜: The outer boundary of the cell, composed of lipids and proteins, controlling the entry and exit of substances. 細胞的外部界限，由脂質和蛋白質組成，控制 物質的進出。 Cytoplasm 細胞質: The liquid inside the cell, containing various organelles and chemicals. 細胞內部的液體，含有各種細胞器和化學物質。 Organelles 細胞器: Specialized structures that perform specific functions, such. 各種特 化結構，執行特定功能 ○ Mitochondria 線粒體: The energy-producing centers responsible for synthesizing ATP (the energy currency). 能量產生中心，負責ATP（能量貨幣）的合 成。 ○ Endoplasmic Reticulum (ER) 內質網: Involved in the synthesis of proteins and lipids. 參與蛋白質和脂質的合成。 ○ Golgi Apparatus 高爾基體: Modifies and transports proteins. 負責修改和運輸蛋 白質。  ○ Nucleus 細胞核: Stores genetic material (DNA) and regulates cellular activities. 儲存遺傳物質（DNA），調控細胞活動。 2. Types of Cells （細胞的類型） Prokaryotic Cells 原核細胞: Found in bacteria and archaea, these cells lack a defined nucleus and have genetic material dispersed in the cytoplasm. They are typically smaller and simpler in structure. 如細菌和古細菌，沒有明確的核膜，遺傳物質散佈在細胞質中。 通常較小，結構較簡單。 Eukaryotic Cells 真核細胞: Found in animals, plants, and fungi, these cells have a defined nucleus and various organelles. They are generally larger and more complex in structure. 如動物、植物和真菌，擁有明確的核和多種細胞器。通常較大，結構較複雜。 3. Cell Functions (細胞的功能) Metabolism 代謝: Cells carry out various chemical reactions to obtain energy and materials for grow th and maintenance of life. 細胞進行各種化學反應以獲取能量和材料 ，用於生長和維持生命。 Reproduction 增殖: Cells proliferate through cell division (such as mitosis and meiosis), passing on genetic information.細胞通過細胞分裂（如有絲分裂和減數分裂）進行增殖，傳 遞遺傳信息。 Differentiation 分化: Cells can transform into specialized types based on their functional requirements (e.g., muscle cells, nerve cells). 細胞根據其功能需求轉變為特定類型的細 胞（例如，肌肉細胞、神經細胞等）。 Signal Transduction 信號傳遞: Cells can receive and transmit signals, regulating their activities and responding to external environments. 細胞能夠接收和傳遞信號，調節其活 動並響應外部環境。 4. Importance of Cells ( 細胞的重要性) Cells are the fundamental units of all life. Understanding cell structure and function is crucial for research in biology, medicine, and genetics. Cell studies help us comprehend life processes, disease mechanisms, and develop treatment methods. 細胞是所有生命的基本單位。對於生物 學、醫學、遺傳學等領域的研究，理解細胞的結構和功能至關重要。細胞研究有助於我們了解生 命過程、疾病機理，以及開發治療方法。 In summary, cells are the basic units of life, performing a variety of functions essential for the normal operation of living organisms. 總之，細胞是生命的基礎單位，承擔著維持生物體正常運作 的多種功能。 —------------------------------------------------------------------------------------------------ Mitosis: Meiosis: 1. 前期 I（Prophase I）：染色體凝縮，同源染色體配對並發生交叉互換。核膜解體，紡錘絲開始形 成。 2. 中期 I（Metaphase I）：同源染色體排在細胞中央，紡錘絲附著到每對同源染色體上。 3. 後期 I（Anaphase I）：同源染色體被拉向細胞兩極，**姐妹染色單體**仍然連在一起。 4. 末期 I（Telophase I）：染色體到達兩極，核膜可能短暫重組。 5. 細胞質分裂（Cytokinesis）：細胞質分裂，產生兩個**單倍體**細胞，每個染色體仍有兩個染色單 體。 —------------------------------------------------------------------------------------------------ DNA and chromosomes (染色體) are key concepts in genetics and cell biology, playing important roles in the storage and transmission of genetic information. 是遺傳學和細胞生物學中的關鍵概念，二者在遺傳信息的儲存和傳遞中扮演著重要角色。 DNA (Deoxyribonucleic Acid) Structure: DNA is a double helix structure composed of two complementary strands of nucleotides. Each nucleotide consists of a phosphate group, a deoxyribose (sugar), and a nitrogenous base (A, T, C, G). DNA 是一種雙螺旋結構，由兩條互 補的核苷酸鏈構成。每個核苷酸包含一個磷酸基團、一個去氧核糖（糖）和一個含氮 鹼基 Function 功能: DNA is the primary medium for storing genetic information in living organisms. It carries the instructions for synthesizing proteins, which in turn affects the structure and function of cells. DNA 是生物遺傳信息的主要儲存介質。它負責合成 蛋白質的指令，從而影響細胞的結構和功能 The sequence of DNA determines the traits and characteristics of organisms. DNA 的序列決定了生物的性狀和特徵。 3. Location位置: In eukaryotic cells, DNA is primarily located within the nucleus and can also be found in organelles like mitochondria and chloroplasts. Bacteria, lacking a nucleus, typically have circular DNA located in the cytoplasm.在真核生物中，DNA 主要位於細胞核內，也可以在線粒體和葉綠體等細胞器中發現。細菌則沒有細胞核， 其 DNA 通常是環狀的，位於細胞質中。 Chromosomes 染色體 1. Structure: Chromosomes are structures composed of DNA and proteins. During cell division, DNA wraps around histones, forming tightly packed chromosome structures. 染色體是由 DNA 和蛋白質（主要是組蛋白）組成的結構。在細胞分裂期 間，DNA 繞繞在組蛋白上，形成緊密包裹的染色體結構。 2. Function: Chromosomes are responsible for the accurate transmission of genetic material during cell division. Each cell requires a complete set of chromosomes to ensure proper gene expression and cellular function. 染色體負責在細胞分裂過程中正確 地傳遞遺傳物質。每個細胞都需要完整的染色體組合以確保正確的基因表達和細胞 功能。 3. Number: Different species have varying numbers of chromosomes. Humans have 46 chromosomes (23 pairs), with one pair being sex chromosomes (XX or XY) and the others being autosomes. 不同物種擁有不同數量的染色體。人類有 46 條染色 體（23 對），其中一對是性染色體（XX 或 XY），其他是常染色體。 Relationship Between DNA and Chromosomes DNA 與染色體的關係 DNA is the fundamental component of chromosomes: Each chromosome is formed by DNA wrapped around histones. When cells divide, chromosomes are replicated to ensure that each daughter cell receives the same genetic information. DNA 是染色體的基本成分：每條染色體都是由 DNA 纏繞在組蛋白上 形成的。當細胞進行分裂時，染色體會被複製，以確保每個子細胞都擁有相同的遺傳 信息。 Conclusion 總結  DNA is the molecule that carries genetic information, while chromosomes are the structures made of DNA that protect and transmit this information during cell division. Both play crucial roles in all processes of life. DNA 是承載遺傳信息的分 子，而染色體是由 DNA 組成的結構，負責在細胞分裂中保護和傳遞這些信息。這兩 者在生命的所有過程中都起著至關重要的作用。 —------------------------------------------------------------------------------------------------ 二分裂（Binary Fission）是一種無性繁殖的方式，通常發生在細菌和某些單細 胞生物中。這種過程使得細胞能夠快速增殖，並且是許多原核生物（如細菌） 繁殖的主要方式。以下是二分裂的詳細介紹： 二分裂的過程Process of Binary Fission 1. 細胞增長 Cell Growth： 在二分裂之前，細胞會進行生長，並準備複製其遺傳物質（DNA）。此時 ，細胞內的各個成分（如核糖體、蛋白質和細胞器）也會增加。Before binary fission, the cell grows and prepares to duplicate its genetic material (DNA). During this phase, the components of the cell (such as ribosomes, proteins, and organelles) also increase. 2. DNA 複製 DNA Replication： 細胞內的 DNA 開始複製，形成兩個相同的 DNA 拷貝。這些拷貝會分 別移動到細胞的兩端。The DNA within the cell begins to replicate, resulting in two identical copies of the DNA. These copies move to opposite ends of the cell. 3. 細胞膜擴張 Cell Membrane Elongation： 隨著 DNA 拷貝的移動，細胞膜開始向內擴張，形成一個細胞隔膜（ septum）在細胞中間。 As the DNA copies move, the cell membrane starts to elongate, forming a septum (a dividing wall) in the middle of the cell. 4. 細胞分裂 Cell Division：  隨著細胞膜的進一步擴張，細胞最終被分為兩個相同的子細胞。每個 子細胞都包含一份完整的 DNA 和細胞的其他組成部分。With further elongation of the cell membrane, the cell eventually divides into two identical daughter cells. Each daughter cell contains a complete set of DNA and other cellular components. 5. 分裂完成 Completion of Division： 分裂後，兩個子細胞獨立存在，並且能夠進一步增殖，繼續重複二分裂 的過程。After division, the two daughter cells exist independently and are capable of further reproducing, continuing the binary fission process. 特點Characteristics 快速繁殖Rapid Reproduction：二分裂使得細菌能夠在有利的環境中快 速繁殖，生成大量的子細胞。favorable environments, generating a large number of daughter cells. 無性繁殖Asexual Reproduction：由於是無性繁殖，子細胞與母細胞在 遺傳上是完全相同的，這意味著缺乏基因多樣性。 Since it is asexual reproduction, the daughter cells are genetically identical to the parent cell, resulting in a lack of genetic diversity. 適應性Adaptability：當環境條件良好時，細菌會利用二分裂快速增殖， 但在環境惡劣時，它們也可能進入休眠狀態，以應對不利條件 When environmental conditions are favorable, bacteria utilize binary fission to reproduce rapidly, but they may also enter a dormant state in adverse conditions to survive. 總結 二分裂是一種簡單而有效的細胞繁殖方式，能夠快速產生大量的子細胞，這 對於細菌等單細胞生物的生存和繁殖至關重要。 Binary Fission is a form of asexual reproduction commonly occurring in bacteria and some single-celled organisms. This process allows cells to reproduce rapidly and is the primary method of reproduction for many prokaryotic organisms (such as bacteria). Here’s a detailed overview of binary fission: Practice/ Review sheet for Science 9 On test: 1. Organelles – 5 2. Cell theory -1 3. Hypothesis – 1 4. DNA/ chromosomes – 3 5. Binary Fission - 4 6. Mitosis -7 7. Meiosis (gamete, zygote, fertilization) - 10 8. Asexual reproduction vs sexual reproduction – 3 1. What is cell theory? Cell theory has three parts: - Everything is made of cells - Cells are the functional unit of all living things - All cells come from other cells 2. What are the parts of a cell? Can you name them? What do they do? 3. What is a hypothesis? A hypothesis is an educated guess. It usually follows “If….then…because” 4. What is DNA? What is chromatin? What is a chromosome? 5. What is binary fission? What type of organism uses it? Binary fission is a type of asexual reproduction where a cell splits into two identical cells. Bacteria use binary fission. 6. What is the purpose of mitosis? What are the phases? Mitosis is for the growth, repair, and continuation of your body cells. It makes IDENTICAL cells with 46 chromosomes. There are 4 phases: PMAT.  7. What is the purpose of meiosis? Where does it happen? What are the phases? The purpose of meiosis is to make 4 genetically DIFFERENT haploid gametes. It happens to your sex cells. There are two rounds of PMAT. The most important part is that each cell is different and mixed during metaphase 1. Makes genetic variation.  8. What is a zygote? Gamete? Haploid? Diploid? Fertilization? A zygote is the first cell that develops into a new organism. A gamete is a male or female sex cell. A sperm or egg cell. Fertilization is the combining of male and female gametes. Haploid is a cell with half the number of chromosomes. In humans that means 23 chromosomes. Diploid is a cell with a complete set of chromosomes. In humans that means 46 chromosomes. 9. What are some differences between mitosis and meiosis? 10. What are the advantages/ disadvantages of sexual and asexual reproduction? Asexual reproduction – fast, no need to find a mate, identical to parent, BUT all die together if things change Sexual reproduction - genetic variation BUT slow, need to find a mate, takes long to raise kids Practice questions: 1. Which organelle is responsible for producing energy in the cell? o a) Nucleus o b) Mitochondria o c) Ribosomes o d) Lysosomes 2. What is the main function of the nucleus? o a) Transporting materials within the cell o b) Storing genetic material  o c) Producing proteins o d) Breaking down waste 3. Which organelle is known as the "control center" of the cell? o a) Cell membrane o b) Chloroplast o c) Nucleus o d) Golgi apparatus 4. Which organelle is involved in protein synthesis? o a) Golgi apparatus o b) Ribosomes o c) Lysosomes o d) Vacuole 5. Which of the following is NOT part of the cell theory? o a) All living things are made of cells o b) The cell is the basic unit of life o c) All cells contain a nucleus o d) All cells come from pre-existing cells 6. What best describes a scientific hypothesis? o a) An untestable idea o b) A random guess o c) A testable statement or prediction o d) A confirmed scientific law 7. What is the main function of DNA in cells? o a) To store energy o b) To control cell movement o c) To carry genetic information o d) To protect the cell 8. Where is DNA located within a cell? o a) In the cytoplasm o b) In the nucleus o c) In the cell membrane o d) In the mitochondria 9. What shape is the DNA molecule often compared to? o a) Ladder o b) Double helix o c) Spiral staircase  o d) Straight line 10. Binary fission is a method of reproduction in which type of organisms? o a) Plants o b) Animals o c) Bacteria o d) Fungi 11. What is the result of binary fission in bacteria? o a) Four identical cells o b) Two identical cells o c) One identical cell and one different cell o d) No cell division 12. Which of the following statements is TRUE about binary fission? o a) It only occurs in multicellular organisms o b) It results in genetically identical cells o c) It is slower than mitosis o d) It produces diverse offspring 13. What is the main purpose of binary fission? o a) Sexual reproduction o b) Asexual reproduction o c) Producing complex cells o d) Energy production 14. What is the main purpose of mitosis? o a) To produce gametes o b) To create genetic diversity o c) To produce identical cells for growth and repair o d) To produce different cells 15. Which phase of mitosis involves chromosomes lining up in the center of the cell? o a) Prophase o b) Metaphase o c) Anaphase o d) Telophase 16. Which of the following is the correct sequence of stages in mitosis? o a) Prophase → Metaphase → Anaphase → Telophase o b) Telophase → Anaphase → Prophase → Metaphase o c) Metaphase → Prophase → Telophase → Anaphase o d) Anaphase → Prophase → Telophase → Metaphase 17. What happens to the cell’s chromosomes during anaphase?  o a) They line up in the center o b) They move to opposite sides of the cell o c) They become invisible o d) They duplicate 18. Mitosis results in the production of: o a) Two identical cells o b) Four identical cells o c) Two different cells o d) One cell with a new DNA sequence 19. Meiosis results in the production of: o a) Two identical cells o b) Four unique gametes o c) Two cells with identical chromosomes o d) Cells with double the chromosome number o Answer: b) Four unique gametes 20. Which cells are produced through meiosis? o a) Body cells o b) Gametes o c) Skin cells o d) Blood cells 21. What happens during fertilization? o a) Gametes are formed o b) Chromosomes are divided o c) A zygote is created o d) Meiosis ends 22. How many chromosomes are in each human gamete after meiosis? o a) 23 o b) 46 o c) 92 o d) 12 23. A zygote is formed by the fusion of: o a) Two body cells o b) A sperm and an egg cell o c) Two sperm cells o d) Two egg cells 24. How many divisions occur during meiosis? o a) One o b) Two o c) Three o d) Four 25. What is a key difference between meiosis and mitosis? o a) Only mitosis produces gametes o b) Mitosis produces four cells; meiosis produces two o c) Meiosis results in genetic diversity; mitosis does not o d) Mitosis occurs only in reproductive organs 26. Gametes are described as: o a) Diploid cells o b) Haploid cells o c) Somatic cells o d) Zygotic cells 27. Which statement best describes asexual reproduction? o a) It requires two parents o b) It results in offspring that are genetically identical to the parent o c) It produces genetically diverse offspring o d) It requires gametes 28. Which of the following is an example of sexual reproduction? o a) Binary fission in bacteria o b) Budding in yeast o c) Fertilization in animals o d) Spore formation in fungi 29. One main difference between sexual and asexual reproduction is: o a) Sexual reproduction produces genetically identical offspring o b) Asexual reproduction requires two parents o c) Asexual reproduction is faster o d) Sexual reproduction results in identical cells Answers: 1. b) Mitochondria 2. b) Storing genetic material 3. c) Nucleus 4. b) Ribosomes 5. c) All cells contain a nucleus 6. c) A testable statement or prediction 7. c) To carry genetic information 8. b) In the nucleus 9. b) Double helix 10. c) Bacteria 11. b) Two identical cells 12. b) It results in genetically identical cells 13. b) Asexual reproduction 14. c) To produce identical cells for growth and repair 15. b) Metaphase 16. a) Prophase → Metaphase → Anaphase → Telophase 17. b) They move to opposite sides of the cell 18. a) Two identical cells 19. b) Four unique gametes 20. b) Gametes 21. c) A zygote is created 22. a) 23 23. b) A sperm and an egg cell 24. b) Two 25. c) Meiosis results in genetic diversity; mitosis does not 26. b) Haploid cells 27. b) It results in offspring that are genetically identical to the parent 28. c) Fertilization in animals 29. c) Asexual reproduction is faster