Unit 2 Quiz PDF - Biology

THIS DOC IS ALL FROM THE TEXTBOOK Review (What to know) - Three points of cell theory - Picture on the first page of 2.1 The picture about prokaryotes and eukaryotes What kind of cells have nucleus and which don't - Organelles are inside cells - Study pictures of th...

THIS DOC IS ALL FROM THE TEXTBOOK Review (What to know) - Three points of cell theory - Picture on the first page of 2.1 The picture about prokaryotes and eukaryotes What kind of cells have nucleus and which don't - Organelles are inside cells - Study pictures of the animal and plant cells (Exactly from the book) - Function of Cells - What DNA stands for on the test - Why is cell division important (Growth, repair, reproduction) - Diffusion and osmosis - 2.5 is the most important - cell cycle - Page 43 pictures for cell cycle - Application q - page 43 if the cell does not have nutrients it will not divide, if the chromosomes is not replicated or dna is not damaged - Few questions from 2.7 - Know metastasis - if one cell is already damaged it becomes a tumor. It will go to another part of the body and cause cancer there. The process of this moving is called metastasis - Carcinogens will be used in the test - Tests to screen cancer - How to reduce cancer risks - What treatments for cancer What happens in each - What are specialized cells - definition - Will be asking Functions of specialized cells - page 59 7 Characteristics of Living Organisms: COWGERL 1. Cells: Life is made up of cells, either unicellular or multicellular, which may form tissues, organs, and organ systems. 2. Reproduction: Organisms reproduce to continue their species, either asexually (one parent) or sexually (genetic material from two parents). 3. Waste: Living things create and eliminate waste as a result of life functions, which includes solids, liquids, and gasses. 4. Growth: Living things grow; single-celled organisms increase in volume, and multicellular organisms add cells. 5. Energy Transformation: Organisms take in and transform energy to power life processes; metabolism encompasses all biochemical reactions. 6. Response to Environment: Organisms react to biotic (living) and abiotic (non-living) factors and respond to stimuli, which can occur at a cellular level (homeostasis). 7. Lifespan and Adaptation: Organisms have lifespans and adapt over time; environmental pressures lead to evolution, enhancing survival and reproduction. Cell Theory Timeline - Hooke 1665: Observed remains of dead plant cells - Leeuwenhoek 1673: First to see a living cell using a simple microscope - Schleiden 1838: All plants are made of cells - Virchow 1855: Reasoned that cells come from other cells. - Schwann 1939: All animals are made of cells Discovery Of The Cell - The microscope was invented in the mid 1600’s. Before this time scientists could not look at cells. - Roberk Hooke was the first to describe cells in 1663. He thought that the cells were the passages for fluids in a plant. 2.1: Plant and Animal Cells Cell Theory: 1. All living things are made up of one or more cells and their products. 2. The cell is the simplest unit that can carry out all life processes. 3. All cells come from other cells, they do not come from nonliving matter. Types of Organisms 1. Prokaryotes ○ Single-celled organisms without a nucleus or membrane-bound organelles. ○ Examples: Archaea, Bacteria, E. coli. 2. Eukaryotes ○ Cells have a nucleus and membrane-bound organelles, with complex internal organization. ○ Can be single-celled or multicellular. Single-celled: One cell (e.g., Amoeba). Multicellular: Many cells (e.g., Whale, Pine Tree). ○ Examples: Protists, Fungi, Animals, Plants. ○ Eukaryotic cells are larger than prokaryotic cells. Cell Structure Eukaryotic Cells: Contain specialized parts called organelles that perform specific functions necessary for life. Organelles: Structures within the cell that each have a unique role to support the cell's function. Structures Common to Plant & Animal Cells All cells perform essential activities to survive, including: ○ Using energy ○ Taking in and storing materials from the environment ○ Removing waste ○ Transporting substances where needed ○ Reproducing Plant & Animal Cells - Cytoplasm: A jelly-like substance that suspends all organelles within the cell. Composed mostly of water and stores substances needed by the cell. Site of many chemical reactions. Can shift from jelly-like to liquid, allowing organelles to move within the cell. - Cell Membrane: Flexible, double-layered membrane surrounding the cell. Supports the cell.  Controls entry and exit of substances; allows small molecules (e.g., water, oxygen) to pass through easily, while blocking larger molecules like proteins. Semi-permeable: Allows selective movement of substances in and out. The membrane has two layers called the phospholipid bilayer. The outer parts of the membrane attract water (hydrophilic), while the inner part repels water (hydrophobic). Organelles: Most eukaryotic organelles have a similar membrane. - Nucleus: Roughly spherical structure within the cell. Contains genetic information that controls all cell activities. Genetic information is stored on chromosomes. Chromosomes: Composed of DNA (deoxyribonucleic acid), which carries coded instructions for cell activities. Cell Division: During cell division, DNA is copied to ensure each new cell has a complete set of chromosomes. Chromatin is a grainy substance made of protein and DNA. During cell division, it condenses to form chromosomes. - Mitochondria: Known as the power plants of the cell; they produce energy for the cell. Cells contain many mitochondria, with active cells (e.g., muscle cells) having more than less active cells (e.g., fat storage cells). Less active cells (e.g., fat cells) may have only one or two mitochondria. Energy Storage: Cells store energy primarily in the form of glucose (a sugar). Cellular Respiration: ○ Mitochondria contain enzymes that convert stored energy into usable forms. ○ This process requires oxygen and produces waste products (carbon dioxide and water). ○ Reaction: Glucose + Oxygen → Carbon dioxide + Water + Energy - Endoplasmic Reticulum: A three-dimensional network of branching tubes and pockets that extends throughout the cytoplasm, connecting the nuclear membrane to the cell membrane.  Transports materials, such as proteins, within the cell through fluid-filled tubes. Plays a crucial role in various cell types: ○ In the brain, it aids in the production and release of hormones. ○ In muscle cells, it is involved in muscle contraction. - Golgi Bodies: Collect and process materials for removal from the cell. Additional Role: Manufacture and secrete mucus. Presence: Cells that produce large amounts of mucus, such as those lining the intestine, contain many Golgi bodies. - Ribosomes Site of protein synthesis - Vacuoles: Membrane-bound sac filled with fluid. Functions: ○ Varies by cell type. ○ Stores substances. ○ Removes unwanted materials. ○ Maintains internal fluid pressure (turgor). Presence: ○ Animal Cells: Many small, often invisible vacuoles. ○ Plant Cells: Large central vacuole, visible under a light microscope. Special Functions: ○ Amoeba: Change shape to engulf food. ○ White Blood Cells: Engulf bacteria; membrane forms a vacuole that digests bacteria and ejects waste. Organelles in Plant Cells Only - Differences from Animal Cells: While plant and animal cells share many common structures, plant cells contain unique organelles not found in animal cells.  - Cell Wall: Found outside the cell membrane in plant cells. Structure: Rigid, porous layer made of cellulose. Functions: ○ Provides structural support for the cell. ○ Offers protection from physical injury. Cellulose can remain intact long after the plant has died (e.g., paper is primarily made from cellulose from tree cell walls). - Vacuole: Plant cells have one large vacuole. Function: ○ Turgor Pressure: Full vacuoles maintain cell firmness and support in stems and leaves. ○ Water Loss Impact: When vacuoles lose water, turgor pressure decreases, causing cells to soften and plants to wilt. - Chloroplast: found in many light-exposed plant cells, like those in leaves. Function: ○ Chlorophyll: Gives leaves their green color and absorbs light energy. ○ Photosynthesis: Converts carbon dioxide and water into glucose and oxygen using light energy. ○ Chemical Equation: Carbon Dioxide + Water + Energy (Sunlight) → Glucose + Oxygen Energy Use: Plants make their own food from sunlight, and plant cells use mitochondria to metabolize glucose, similar to animal cells. 2.3: The Importance of Cell Division - You started life as a single cell (A fertilized egg). Now your body is made up of trillions of cells. - Cell division allows organisms to reproduce, to grow and to repair damage. Cell Division for Reproduction: - Importance of Reproduction: ○ All living things, from bacteria to elephants, reproduce through cell division. - Asexual Reproduction: ○ Involves a single parent cell dividing to create two identical offspring.  ○ Each offspring inherits a complete set of genetic information from the parent. ○ Offspring are exact genetic copies of the parent. - Multicellular Organisms: ○ Can also reproduce asexually, producing young with the same DNA as the parent. - Sexual Reproduction: ○ Involves the combination of two gametes (sex cells) from different parents. ○ Gametes contain half the DNA of normal body cells. ○ These gametes are formed through meiosis, a special type of cell division. - Combination of Gametes: ○ When gametes combine, the offspring inherit characteristics from both parents. Cell Division for Growth: - Growth as a Characteristic of Life: All organisms grow, primarily by increasing the number of cells. - Basic Needs of Cells: Energy Source: Required for cellular functions and growth. Nutrients: Essential for building cellular structures and supporting metabolic processes. Water: ○ Crucial for chemical reactions; many substances must be dissolved in water to be utilized by the cell. ○ Cells need to maintain a high water content. - Excretion of Waste: Cells must remove waste products, including carbon dioxide, to maintain homeostasis and proper functioning. Why does the number of cells increase as organisms grow? - Cell Number Increase: As organisms grow, the number of cells increases to support their larger size and complexity. Nutrients and waste can’t move in and out of a large cell quickly.  The DNA in the nucleus becomes overloaded with demands for instructions. If cells only grow bigger, a few nuclei and limited DNA won’t be able to control the entire cell effectively. Cell division helps prevent this DNA overload by providing each new cell with its own copy of DNA. - Chemical Movement in Cells: Entry Across the Membrane: Chemicals necessary for cell activity and growth enter through the cell membrane. Diffusion: The movement of these chemicals occurs via diffusion, a natural process where: ○ Chemicals move from an area of higher concentration to an area of lower concentration. ○ This process helps distribute essential substances throughout the cell. - Concentration: Refers to the amount of solute (substance) in a given volume of solution. Understanding concentration is important for grasping how diffusion works and how cells acquire the chemicals they need. Osmosis: - The movement of water across a semipermeable membrane. - Water moves towards the area of greater solute concentration. If one side of the membrane has a higher concentration of solute (e.g., salt or sugar), water will move to that side to balance the concentration of solute on both sides. Diffusion & Osmosis: - Importance for Cell Function: Cells need important chemicals and the right amount of water to work properly. - Waste Removal: Waste products must diffuse out quickly to prevent toxicity in the cell. - Limitations of Cell Size: If a cell gets too large, it becomes difficult for chemicals and water to move throughout the cell. - Concentration: The amount of a substance (solute) in a specific volume of solution. Cell Division for Repair: - Skin Cell Replacement: Your body sheds millions of dead skin cells daily, replaced by new cells.  - Red Blood Cell Renewal: Red blood cells are replaced approximately every 120 days. - Bone Healing: When a bone breaks, cells divide to help heal the injury. - Wound Repair: Cuts and blisters require new cells to fill in the gaps. - Importance of Repair: All organisms need to repair themselves to survive. 2.5: The Cell Cycle - Definition: The cell cycle is the series of stages that eukaryotic cells go through as they grow and divide. - Stages of the Cell Cycle: Interphase: Cells grow and prepare for division. Mitosis: The process of cell division occurs. Cytokinesis: The cell splits into two new cells. - Cycle Duration: The time to complete one cycle varies: ○ Embryonic cells divide rapidly. ○ Some body cells can take up to 30 hours to complete a cycle. ○ Specialized cells, like adult nerve cells, may never divide. Chromosome: A single DNA molecule within the nucleus - Chromatid: one of two identical strands of DNA that make up a duplicated chromosome. - Centromere: structure that holds chromatids together as chromosomes - Centre is the centromere, each leaf is a chromatid and the whole thing together is the chromosome Interphase: - Longest Stage: Interphase is the longest stage of the cell cycle but is not a resting phase. - Active Life Activities: During interphase, the cell performs essential activities like: Growth Cellular respiration  Specialized functions specific to the cell type. - Genetic Material: DNA exists as long, thin, invisible strands. - Preparation for Division: Before cell division, DNA strands are duplicated to create two identical strands. Additional organelles are also formed during this phase. Cell Division: - Stages of Cell Division: Cell division occurs in two main stages: Mitosis: Division of the nucleus. Cytokinesis: Division of the cytoplasm, organelles, and cell membrane. - Daughter Cells: - Each division results in two genetically identical cells called daughter cells. - Phases of Mitosis: - Mitosis consists of four phases, often remembered as PMAT: - Prophase - Metaphase - Anaphase - Telophase Cells transition gradually through these phases. Prophase: - Beginning of Mitosis: Prophase is the first phase of mitosis, following interphase. - Condensation of DNA: Long strands of DNA condense into visible structures called chromosomes. - Sister Chromatids: Each chromosome consists of two identical strands known as sister chromatids. An individual strand is called a chromatid. - Centromere: Sister chromatids are connected at a region called the centromere. - Nuclear Membrane Breakdown: The nuclear membrane breaks down during prophase, allowing the chromosomes to be accessed for division. Metaphase: - Chromosome Alignment: During metaphase, chromosomes line up along the middle of the cell. - Easily Recognized Stage: This stage is easily identifiable due to the distinct arrangement of chromosomes.  - Requirement for Mitosis: All chromosomes must be properly aligned in the middle for mitosis to proceed to the next phase. Anaphase: - Centromere Splitting: In anaphase, the centromere splits, allowing sister chromatids to separate. - Daughter Chromosomes: Once separated, the sister chromatids are referred to as daughter chromosomes. - Movement to Opposite Sides: Daughter chromosomes move toward opposite sides of the cell. - Visual Appearance: Under a microscope, the chromosomes appear to be pulled apart during this phase. Telophase: - Final Stage: Telophase is the last phase of mitosis. - Chromosome Changes: Daughter chromosomes stretch out, become thinner, and are no longer visible. - Nuclear Membrane Formation: New nuclear membranes form around each group of daughter chromosomes. - Cell Appearance: The cell appears to have two nuclei at this stage. Cytokinesis: - Final Stage: Cytokinesis is the last stage of cell division. - Cytoplasm Division: Divides the cytoplasm, resulting in two genetically identical daughter cells. - Plant Cells: A plate forms between daughter cells, developing into a new cell wall. - Animal Cells: The cell membrane is pinched off in the center. Moving the Chromosomes: - Chromosome Movement: Controlled by spindle fibers during mitosis. - Spindle Fiber Formation: Begin forming during late interphase. - Prophase and Metaphase: Spindle fibers pull chromosomes to the center of the cell. - Anaphase: Spindle fibers pull daughter chromosomes toward opposite ends of the cell. Checkpoints in the Cell Cycle: - Checkpoints: Specific points in the cell cycle that control cell activities.  - Monitoring Proteins: Specialized proteins assess cell activities and surroundings at each checkpoint. - Nucleus Instructions: Proteins send messages to the nucleus to decide if the cell should divide. - Interphase Conditions: A cell should remain in interphase (not divide) if: Signals from surrounding cells indicate not to divide. There are insufficient nutrients for cell growth. DNA has not been replicated. DNA is damaged. - DNA Repair: If DNA is damaged early in the cycle, there may be time for repair; excessive damage typically leads to cell destruction. - Health Maintenance: This process is essential for keeping organisms healthy. 2.7: Cell Division Going Wrong: Cancer - Cancer: A group of diseases where cells grow and divide uncontrollably. - DNA Changes: Results from alterations in DNA that regulate the cell cycle, preventing normal interphase duration. - Checkpoint Failure: One or more checkpoints fail, leading to continuous, uncontrolled cell division in the affected cell and its daughter cells. - Causes: Some cancers are hereditary (run in families). Others are triggered by environmental factors. Some cancers may have both hereditary and environmental causes. - Infectiousness: Cancer is not infectious; it cannot be transmitted from one individual to another - Occurrence in Organisms: Cancer affects not only humans but also other organisms, including cats, dogs, fish, and even plants. Cell Growth Rates and Cancer: - Cancer Cell: Divide uncontrollably, ignoring signals from the nucleus or surrounding cells to stop growing. - Checkpoint Failure: Checkpoints may fail to detect problems or eliminate malfunctioning cells. - Tumor Formation: Benign Tumors: ○ Form a mass of cells that may remain together and not seriously affect surrounding tissues. ○ Not cancerous, but can grow large enough to crowd nearby cells and disrupt their normal function.  Malignant Tumors: ○ Interfere with neighboring cells and tissues, impacting functions like enzyme or hormone production. ○ Considered cancerous and may destroy surrounding tissues. Metastasis: ○ Cancer cells can break away from the primary tumor and spread to other parts of the body. ○ If they establish a new mass of cells in a different location, this is known as a secondary tumor. ○ Metastasis is a significant factor in the danger posed by cancer. Causes of Cancer: - DNA Duplication: Each time a cell divides, its DNA is duplicated accurately, ensuring genetic information in daughter cells matches that of the parent cell. - Mutations: Random changes in DNA can occur, known as mutations. Mutations can lead to cell death or allow the cell to survive, grow, and divide. - Cancer Development: If mutations affect DNA that controls cell division, cells may become cancerous and proliferate through uncontrolled mitosis and cytokinesis. Cancerous cells multiply until nutrients are depleted. - Carcinogens: Some mutations are caused by carcinogens—environmental factors that can lead to cancer. Common carcinogens include: ○ Tobacco smoke ○ Radiation (e.g., x-rays, UV rays from tanning beds and sunlight) ○ Certain viruses (e.g., human papillomavirus (HPV), hepatitis B) ○ Chemicals in plastics and organic solvents. - Exposure Variability: Not everyone exposed to carcinogens will develop cancer, making prediction difficult for researchers. - Hereditary Cancers: Some cancers have a hereditary component, meaning DNA passed from parents may increase the risk of certain cancers (e.g., some breast and colon cancers). A genetic link raises the likelihood of developing cancer but does not guarantee it. Smoking and Cancer: - Lung Cancer Prevalence: One of the most common cancers in Canadians over 40. - Smoking Impact: Responsible for 9 out of 10 cases of lung cancer, according to Health Canada. - Carcinogens: Tobacco contains carcinogens that affect not only the lungs but also increase the risk of more than a dozen other cancer types. - Prevention: Most smoking-related cancers can be prevented by: Quitting smoking. Never starting to smoke. Avoiding secondhand smoke. Cancer Screening: - Checking for cancer without symptoms. - Methods: - Can be done at home, during routine medical checkups, or with special appointments. - Importance of Screening: - Especially vital for individuals with a family history of cancers (e.g., breast or colon cancer). - Genetic screening can determine if inherited DNA linked to cancer is present. - Valuable for those exposed to carcinogens due to work or lifestyle. - Benefits: - Screening does not prevent cancer but increases the chances of early detection for successful treatment, reducing overall risk. - Self-Examinations: - Women perform regular breast self-examinations to check for lumps indicating breast cancer. - Regular Pap Tests for cervical cancer starting around age 18, involving a cervical cell sample. - Men's Screening: - Testicular self-examination for early detection of testicular cancer. - PSA test (blood test) for prostate cancer, less common for men under 50 due to lower incidence rates. - Other Tests: - Blood test for colon cancer. - Regular skin checks by doctors or dermatologists for changes in moles, new growths, and sores.  - Learning to check one's own skin regularly for moles is encouraged. Reducing Your Cancer Risk: - Importance of Prevention and Early Detection: Essential for reducing cancer risk. - Risk Factors: Personal and family medical history. Exposure to environmental carcinogens. Lifestyle choices. - Taking Action: Inform yourself about risk factors to minimize exposure. Family history and some environmental factors cannot be changed. Lifestyle choices, like diet, exercise, and avoiding carcinogens, can significantly reduce cancer risk. Lifestyle choices: - Healthy Diet: - Eating plenty of fruits, vegetables, and less fatty meat can help lower cancer risk. - Certain "superfoods" contain protective substances beneficial for cancer prevention. - Food vs. Supplements: - While some vitamin supplements contain these substances, consuming whole foods is more effective. - Superfoods do not prevent cancer outright but reduce cancer risk. - Body Fat and Cancer Risk: - Higher body fat can increase the risk of some cancers. - A healthy diet may support weight loss, further lowering cancer risk. Diagnosing Cancer: - Tumor Symptoms: Tumors may cause swelling, discomfort, fatigue, or unexplained weight loss. - Early Diagnosis: Early cancer detection improves treatment success. - Diagnostic Tests: If cancer is suspected, doctors may order blood tests and imaging techniques to investigate. Imaging Technologies: - Endoscopy: Used for colon cancer screening. An endoscope with a camera is inserted into the colon; it may include forceps for taking biopsy samples. - X-ray: Used for imaging bones, lungs, and breast tissue (mammograms). Can damage DNA, especially harmful to rapidly dividing cells; avoided during pregnancy. - Ultrasound: - Uses high-frequency sound waves to create images of soft tissues (e.g., heart, liver). - CT Scan: - Multiple X-rays taken from different angles and assembled into detailed images by a computer. - Useful for areas not visible with conventional X-rays. - MRI: - Uses radio waves and a magnetic field for highly detailed images. - Can create 3D models of body structures for thorough examination. Examining Cells: - Confirming Cancer: If tests or imaging show abnormal results, a cell sample is examined under a microscope to confirm cancer. Blood Samples: ○ Blood cancers like leukemia are identified by an unusually high number of white blood cells compared to red blood cells. Tumor Biopsy: ○ Tumor cells are surgically removed for examination. ○ If cells are non-cancerous, the tumor is classified as benign. Identifying Cancer Cells: ○ Cancer cells often look different from normal cells—they may be irregularly shaped or vary in size. ○ Trained medical professionals can recognize cancer cells by examining their shape and structure.  Next Steps After Diagnosis: ○ Doctors determine: Where the cancer began. The tumor’s size and growth rate. Whether the cancer has spread. ○ This information guides treatment options and helps predict the likely outcomes. Treatments for Cancer: - Goals of Cancer Treatment: To slow down tumor growth or destroy as many cancer cells as possible. - Main Cancer Treatments: Surgery: Removes tumors from the body. Chemotherapy: Uses drugs to kill cancer cells throughout the body. Radiation Therapy: Uses targeted radiation to kill or shrink cancer cells in specific areas. Biophotonics: A new technique using light to detect and treat cancer cells. - Treatment Plans: Doctors may use one or a combination of these treatments depending on the type and stage of cancer. - Cancer Treatment Team: Specialists involved may include: ○ Surgeons: Perform operations to remove tumors. ○ Medical Oncologists: Specialists in cancer diagnosis and treatment. ○ Radiation Oncologists: Experts in radiation therapy. ○ Oncology Nurses: Provide specialized care and support to cancer patients. Surgery: - Involves physically removing cancerous tissue. - Often preferred when: The tumor is in an accessible location.  The tumor is well-defined and can be clearly separated from surrounding tissues. Chemotherapy: - Chemotherapy: Uses drugs to treat cancer by: ○ Slowing or stopping cancer cell division and spread. ○ Killing cancer cells throughout the body. Administration: ○ Drugs can be injected or taken orally. Side Effects: ○ Common effects include hair loss, nausea, and fatigue. ○ Despite side effects, the benefits usually outweigh these negatives. Purpose: ○ Often an initial treatment step to shrink tumors for easier surgical removal or to prepare for radiation. Key Advantage: ○ Drugs circulate throughout the body, targeting both large and undetectably small tumors. Radiation: - Radiation Therapy: Targets cancer cells, which are more susceptible to damage from ionizing radiation due to their rapid division. Mechanism: ○ Radiation damages the DNA of cancer cells, preventing them from dividing and growing. Delivery Methods: ○ Focused Beam: Radiation is directed precisely at the tumor. ○ Radioactive Implants: A radioactive source is placed directly into the tumor. Benefits: ○ Targeting the tumor helps minimize side effects to surrounding healthy tissue. Biophotonics:  - A new method in cancer treatment that uses beams of light for detection and treatment. - Advantages: Highly sensitive, allowing for early detection of cancer. Fewer side effects compared to conventional radiation therapy due to precise targeting of cancerous tissue. - Research Hub: Much of the biophotonics research is being conducted at the University of Toronto. - Role of Research: Scientific research and technological advancements are crucial for understanding cell biology. Canadian researchers are leading the way in developing improved methods for cancer prevention, diagnosis, and treatment. Specialized Cells: - Cell Theory: States that all cells arise from previously existing cells. - Origin of Life: Every organism, including humans and trees, begins as a single fertilized egg or cell. - Cell Diversity: Cells in complex organisms are not all identical; they have various structures and functions. - Specialized Cells: Not every cell can perform all functions like digesting food, fighting disease, or carrying nutrients. Specialized cells have unique physical and chemical characteristics that enable them to excel at specific tasks. - Cell Specialization: Involves changes in both form and function, leading to significant differences in appearance among specialized cells. - Animal Cell Specialization: Animal cells exhibit a wide range of specializations, differing in both internal and external structures. Examples of Specialized Cells: ○ Muscle Cells: Have numerous mitochondria to generate the energy required for contraction and movement.  Mucus-Producing Cells (found in the intestine): ○ Contain many Golgi bodies for the processing and secretion of mucus. Function of Specialization: ○ Each type of specialized cell is designed to efficiently perform its specific function within the organism. Red Blood Cells: Contain hemoglobin that carries oxygen in blood. The cells are smooth so that they can easily pass through the blood vessels. Skin Cells: Layers of skin cells fit together tightly covering the outside of the body to protect the cells inside and to reduce water loss. Bone Cells: Collect Calcium from food and allow the growth and repair of bones. They build up bone around themselves creating the body's skeleton. Muscle Cells: Are arranged in bundles called muscle fibers. Muscle cells can contract which makes the fiber shorter and causes bones to move. White Blood Cells: Can move like an amoeba to engulf bacteria and fight infection. Sperm Cells: Are able to move independently carrying DNA from the male parent to join with an egg cell from the female parent. Fat Cells: Have a large vacuole in which to store fat molecules. This is how the cell stores chemical energy. Nerve Cells: Are long, thin and have many branches. They conduct electrical impulses to coordinate body activity. Light-Emitting Cells: Some nocturnal animals and deep-sea creatures possess photophores, specialized cells that can emit light. Plant Cell Specialization: - Plants also have specialized cells with distinct structures and functions: Photosynthetic Cells: (Leaf Cells) Contain many chloroplasts to capture sunlight and make sugar. Xylem (Trunk) Cells: Designed for support and transport of nutrients and water throughout the plant. Move water and dissolved minerals throughout the plant. Ground Tissue Cells (Storage Cells): Store starch, which provides energy for the plant. Phloem Cells: Move dissolved sugars around the plant. Epidermal Cells (on young roots): Have root hairs to absorb water from the soil. Guard Cells (on leaf surfaces): Control water loss. Overall Specialization: - Both animals and plants have specialized cells tailored to their specific environments and functions. Factors Affecting Cell Specialization: Contents of Cytoplasm: The amount and type of organelles (e.g., mitochondria) vary depending on the cell’s function. For instance, neurons have more mitochondria than skin cells because they need more energy. Environmental Conditions: Factors like temperature and nutrient availability can influence cell development and specialization. Neighboring Cells: Nearby cells can affect each other by releasing substances that influence gene expression in adjacent cells. These factors contribute to different gene expressions in cells, leading to specialization, despite all cells having identical DNA. Abnormal Cell Development:  - Environmental contamination or harmful signals can interfere with normal development. Stem Cells: - These are undifferentiated cells capable of becoming various cell types. Stored at birth, stem cells from the umbilical cord can potentially address future medical needs, though preserving them is complex.