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Telophase I

06. Telophase

biology 2.1Unit 2.1: Mitosis and Meiosis Introduction By the end of this section, you should be able to: Define a chromosome. Define DNA as the genetic material. Define genes. Describe the structure of chromosomes. Describe the components of DNA. Define mitosis and describe its stages. Define meiosis and describe its stages. Relate the events of meiosis to the formation of sex cells. Compare mitosis and meiosis. Chromosomes, Genes, and DNA Almost all the cells of your body—except for mature red blood cells—contain a nucleus, which acts as the control center of the cell. The nucleus holds all the information needed to make a new cell and, ultimately, a new individual. Inside the nucleus are chromosomes, thread-like structures that store genetic information passed from parents to offspring. Chromosomes are made up of DNA (deoxyribonucleic acid), a molecule that carries the instructions needed to make all the proteins in your body. Many of these proteins are enzymes, which control the production of other chemicals and affect everything about how your body functions. Each species has a specific number of chromosomes: Humans have 46 chromosomes (23 pairs). Tomatoes have 24 chromosomes (12 pairs). Elephants have 56 chromosomes (28 pairs). Half of your chromosomes come from your mother, and the other half from your father. These chromosomes are arranged in homologous pairs, meaning they contain matching sets of genes. A karyotype is a special photograph that arranges chromosomes into their pairs. In humans, 22 pairs of chromosomes are called autosomes, which control most body functions. The 23rd pair is the sex chromosomes, which determine whether you are male or female: Females have two X chromosomes (XX). Males have one X and one Y chromosome (XY). DNA Structure DNA is a long, twisted molecule shaped like a double helix (a spiraled ladder). Each strand of DNA is made up of smaller molecules called nucleotides, which consist of: A phosphate group A sugar (deoxyribose) A nitrogen base The four nitrogen bases in DNA are: Adenine (A) → Always pairs with Thymine (T) Cytosine (C) → Always pairs with Guanine (G) Genes are small segments of DNA that carry instructions for making proteins. The sequence of these bases acts like a biological code, directing the cell to create specific proteins. In 1953, James Watson and Francis Crick, using data from Rosalind Franklin’s X-ray photographs, discovered the double-helix structure of DNA. Their discovery led to a huge increase in genetic research, including the Human Genome Project, which mapped all human genes. Mitosis (Cell Division for Growth and Repair) All body cells (somatic cells) divide using mitosis, a type of cell division that creates two identical daughter cells. Mitosis is essential for: Growth (producing new cells). Tissue repair (replacing damaged or old cells). Asexual reproduction (producing offspring with identical DNA). Stages of Mitosis Interphase The cell prepares for division by copying its DNA. Chromosomes are not visible under a microscope. Prophase Chromosomes condense and become visible. The nuclear membrane breaks down. Metaphase Chromosomes line up in the center of the cell. Spindle fibers attach to each chromosome. Anaphase The spindle fibers pull the sister chromatids apart to opposite ends of the cell. Telophase A new nuclear membrane forms around each set of chromosomes. The cell is almost ready to split. Cytokinesis The cytoplasm divides, forming two identical daughter cells. Mitosis is constantly occurring in areas like your skin and bone marrow, where new cells are needed regularly. Meiosis (Cell Division for Reproduction) Unlike mitosis, meiosis occurs only in the reproductive organs (testes in males, ovaries in females) and produces gametes (sperm and egg cells). Gametes have half the number of chromosomes (haploid, n=23) so that when fertilization occurs, the new cell has the correct chromosome number (diploid, 2n=46). Stages of Meiosis Meiosis consists of two rounds of cell division, resulting in four non-identical cells. Meiosis I: Prophase I – Chromosomes pair up and exchange genetic material (crossing over). Metaphase I – Chromosome pairs line up in the center of the cell. Anaphase I – Chromosome pairs separate and move to opposite ends of the cell. Telophase I & Cytokinesis – The cell splits into two haploid daughter cells. Meiosis II (similar to mitosis): 5. Prophase II – Chromosomes condense again. 6. Metaphase II – Chromosomes line up in the center. 7. Anaphase II – Sister chromatids separate and move to opposite sides. 8. Telophase II & Cytokinesis – Four unique haploid gametes are formed. Each gamete is genetically different due to crossing over and random chromosome distribution. Mitosis vs. Meiosis: Key Differences Importance of Mitosis and Meiosis Mitosis ensures that cells grow, repair damage, and replace old cells. Meiosis allows genetic diversity, which is essential for evolution and survival. Summary Chromosomes carry genetic information in the form of DNA. Genes are sections of DNA that code for proteins. Mitosis produces two identical daughter cells for growth and repair. Meiosis creates four non-identical sex cells for reproduction. Mitosis ensures genetic stability, while meiosis introduces genetic diversity

Know the relationship between molecular weight and rate of diffusion The rate of diffusion is inversely proportional to the molecular weight Small weight-fast diffusion; heavy weight-slow diffusion Identify RBC’s in various solution and determine tonicity Tonicity - the ability of an extracellular solution to make water move into or out of a cell by osmosis If a cell is placed in a hypertonic solution, there will be a net flow of water out of the cell, and the cell will lose volume (shrink). A solution will be hypertonic to a cell if its solute concentration is higher than that inside the cell, and the solutes cannot cross the membrane. If a cell is placed in a hypotonic solution, there will be a net flow of water into the cell, the cell will gain volume (bigger). If the solute concentration outside the cell is lower than inside the cell, then solutes cannot cross the membrane, then the solution is hypotonic to the cell. If a cell is placed in an isotonic solution, there will be no set flow of water into or out of the cell, and the cell’s volume will remain stable. If the solute concentration outside the cell is the same as inside the cell, and the solutes cannot cross the membrane, the solution is isotonic to the cell. Homeostatic feedback loop for respiratory rate, heart rate and temperature Respiratory Rate: Stimulus : The level of carbon dioxide (CO2) in the blood increases (often due to exercise or hypoventilation) . Receptors: Chemoreceptors in the medulla oblongata, carotid arteries, and aortic arch detect changes in blood pH and CO2 levels Control Center: The medulla oblongata processes this information Effectors: Respiratory muscles (diaphragm and intercostal) adjust breathing rate and depth Response: Increased respiratory rate removes CO2 and increases O2 intake, restoring normal pH and gas levels. Heart Rate: Stimulus : Changes in blood pressure, O2, CO2, or pH levels Receptors: Baroreceptors (detect blood pressure changes) in the carotid sinus and aortic arch; chemoreceptors monitor blood chemistry Control Center: The medulla oblongata (cardiac center) processes signals Effectors : The autonomic nervous system (ANS) adjusts heart rate through the sympathetic nervous system (increases heart rate) or parasympathetic nervous system (decreases heart rate) Response : Heart rate increases during low O2 or low blood pressure (to circulate oxygen) and decreases when homeostasis is restored. Temperature Regulation Stimulus: Changes in body temperature (hyperthermia or hypothermia) Receptors: Thermoreceptors in the skin and hypothalamus detect temperature fluctuations. Control Center: The hypothalamus processes this information and signals effectors Effectors and Responses: If too hot: Blood vessels dilate (vasodilation) to release heat, and sweat glands produce sweat for cooling If too cold: Blood vessels constrict (vasoconstriction) to retain heat, and shivering generates warmth. Steps of a generic homeostatic feedback loop Stimulus : A change in the internal or external environment that disrupts homeostasis (eg. temperature change, pH levels, blood sugar levels) Sensor (Receptor) : Specialized cells or receptors detect the change and send information to the control center. Control Center (Integrator): Often the brain or endocrine glands, this component processes the information from the sensors and determines the appropriate response to restore balance. Effector: This component carries out the response to the stimulus as dictated by the control center. Effectors can be muscles or glands that help to counteract the change. Response: The action taken by the effectors to restore homeostasis. This could involve increasing or decreasing a physiological process (e.g. sweating to cool down or shivering to warm up) Feedback: The results of the response are monitored. If homeostasis is restored, the system maintains its state; if not, the loop may repeat, continuing to adjust until balance is achieved. How to evaluate data to determine the set point, error, and disturbance Identify the set point The set point is the optimal level or range that the system aims to maintain. To determine the set point: Gather baseline data: Collect data over a period to understand the normal range for the variable in question (e.g. body temp., BP, blood glucose levels) Analyze Trends: Look for patterns in the data to identify the average or median value that represents the stable condition of the system. Consult Literature: Reference established physiological norms or previous studies to confirm the typical set point for the variable. Assess Disturbance A disturbance is any factor or event that causes a deviation from the set point. To evaluate disturbances: Identify External and Internal Factors: Analyze the data for any external influences (e.g. environmental changes, dietary habits) or internal changes (e.g. illness, stress) that might have impacted the variable. Quantity Disturbance: Measure the magnitude and duration of the disturbance. This can be done by comparing the data points during the disturbance against the established set point. Monitor Changes: Track how the system responds to disturbances over time to assess their impact on maintaining homeostasis. WBC types and normal distribution values/ abnormal values and what those values indicate (infections/diseases) (Never Let Monkeys Eat Bananas) Neutrophils (50-70%) - First responders to infections, especially bacterial. High levels indicate bacterial infections, inflammation, or stress. Low levels can indicate bone marrow disorders or severe infections. Lymphocytes (20-40%) - Include B cells and T cells, important for immunity. High levels can suggest viral infections or leukemia, while low levels might indicate immune deficiency. Monocytes (2-8%) - Help with cleaning up dead cells and fighting infections. High levels can be linked to chronic infections or autoimmune diseases. Eosinophils (1-4%) - Involved in allergic reactions and fighting parasites. Elevated levels may indicate allergies or parasitic infections. Basophils (0.5-1%) - Release histamine during allergic reactions. High levels might be see in allergic conditions or blood disorders. Normal WBC Count Total WBC Count: 4000-11000 cells per microliter of blood (varies slightly by lab) Leukocytosis (High WBC): Can indicate infection, inflammation, stress, or leukemia Leukopenia (Low WBC): Can result from bone marrow disorders, viral infections, or autoimmune diseases Neutrophils: Banded vs Segmented Neutrophils are the most abundant type of white blood cells and play a crucial role in fighting infections. They exist in different stages of maturation: Banded Neutrophils (“Bands”) - Immature Neutrophils Appearance: Have a curved, unsegmented nucleus (band-shaped) Normal Range: 0-6% of total WBC count (~0-700/uL) Clinical Significance: Increased Bands (Bandemia) -> Indicates an acute bacterial infection or severe stress (e.g. sepsis). The bone marrow releases immature neutrophils in response to infection. Low Bands -> Not clinically significant unless the total WBC count is low, which could suggest bone marrow suppression. Segmented Neutrophils (“Segs”) - Mature Neutrophils Appearance: Have a segmented nucleus with 2-5 lobes Normal Range: 50-70% of total WBC count (~2500-7000/uL) Clinical Significance: High Segs (Neutrophilia) -> Suggests bacterial infections, stress, chronic inflammation, or leukemia Low Segs (Neutropenia) ->Can be caused by viral infections, bone marrow disorders, chemotherapy, or autoimmune diseases. Discuss the stages of cell cycle/mitosis-which stages are longest/shortest The cell cycle is a series of events that cells go through to grow and divide. It consists of two main phases: Interphase (Longest Phase) – Preparation for division Mitosis (Shortest Phase) – Actual cell division Stages of the Cell Cycle Interphase (90% of the Cell Cycle – Longest Phase) Interphase is the period of cell growth and DNA replication. It has three subphases: G1 Phase (Gap 1) The cell grows, produces proteins, and prepares for DNA replication. Longest variable phase; some cells may stay here indefinitely (e.g., neurons in G0 phase). S Phase (Synthesis) DNA replication occurs, ensuring each daughter cell gets a complete genome. Takes about 6-8 hours in human cells. G2 Phase (Gap 2) The cell prepares for mitosis by producing proteins and organelles. Shorter than G1 but still significant in length. Mitosis: Prophase, Metaphase, Anaphase, Telophase Know proportional and inversely proportional relationships Direct (Proportional) Relationship When two quantities increase or decrease together at a constant rate, they are directly proportional. Inversely Proportional When one variable increases, the other decreases proportionally. Know relationship between molecular weight and rate of diffusion The rate of diffusion of a substance is inversely proportional to the square root of its molecular weight. Lighter molecules diffuse faster Heavier molecules diffuse slower due to greater mass. Know relationship between filtration rate and pressure of fluid or weight of fluid Filtration rate is directly proportional to the pressure or weight of the fluid driving the filtration process. Higher pressure → Higher filtration rate Lower pressure → Lower filtration rate Know why men and women blood values are different The differences in blood values between men and women are due to biological, hormonal, and physiological factors

13: metaphase, anaphase, telophase, cytokenisis

You place a RBC (0.9%) into a 5% sugar solution. Which statement below is false? The RBC is hypotonic to the 5% solution Which is an example of a sensor in a negative homeostatic feedback loop? Chemoreceptor in carotid body For membrane fluidity experiment, the part of the experiment that actually validated that the membrane was fluid was: The labeled antibodies of the human and mouse intermixing An example of primary active transport would be a protein requiring ATP to transport sodium ions across the plasma membrane. True If a red blood cell is put in a solution and it hemolyzes, then the solution is considered to be: Hypotonic If your body temperature goes too high you can denature enzymes in your body. True What does an integrator do in a homeostatic pathway? Measures the signal coming in to a set point and send a signal out to the body Which of the following represents stages of the cell division (mitosis) in the proper sequence? Prophase, metaphase, anaphase, telophase Which is not true for proteins? They are comprised of mostly cellulose What would be a disturbance for blood glucose homeostasis (normal blood glucose set point = 77mg/dL)? A permanent decrease in insulin production from the Islets of Langerhans Dr. Bio measures your total cholesterol and he reports back to you that your level is 300 mg/ 100 ml of plasma. You do what? Eat more oatmeal and flax to increase your HDL level. How do you make an unsaturated fatty acid? Perform a dehydration synthesis reaction on a saturated fatty acid Which is false for antioxidants? They speed up reactions in your body Which molecules do not dissolve in water? Non-polar Which molecule requires a transport protein to get through the plasma membrane (either channel or carrier protein)? Two of the answers are correct Interphase is considered to be part of normal cell division (mitosis). False What is the function of ATP? All of the answers are correct What are the three kinds of lipids? Triglycerides, phospholipids, and steroids When glycerol combines with 3 fatty acids to form a triglyceride (fat), which of the following chemical reactions has occurred? Dehydration Synthesis How can you alter a protein’s shape? More than one answer is correct If a red blood cell is put into a solution and it maintains its shape, then the solution is considered to be: Isotonic Which molecule requires some type of transport protein to get through the plasma membrane? Sodium Ion Cofactors are molecules that activate enzymes. Which is not a cofactor? Mercury The nitrogenous bases found in DNA have complementary paring. Which pair is correct? C-G Which is not true for meiosis? Results in a gamete that is 2N In the diagram below the two solutions are separated by a semi permeable membrane. In which direction will net movement of water occur? From side A to side B Which is not a component of a DNA molecule: Ribose Sugar Phospholipids are similar to fatty acids except for? Phospholipids have a phosphate group Which is not true for cells? They allow diffusion of all molecules If you combine a molecule of glucose and fructose, which statement is true? You have formed sucrose Which is true for enzymes? Activity will increase until the enzyme becomes saturated What method would you use to get glucose into a cell along/down it’s concentration gradient (from high to low)? Facilitated Diffusion Which is not considered an integrator in a negative homeostatic feedback loop? Pancreas Which phase of the cell cycle is where cytokinesis takes place? Telophase What vitamin do we produce by sitting in the sun; it aids in calcium absorption from the small intestine? Vitamin D Why is it important to think about ion dissociation in the body? All the above In what order do you use macromolecules for fuel? Carbohydrates, lipids, proteins Which is false for cholesterol? It can dissolve in water/blood You place a RBC (0.9%) into a 0.5% sugar solution. Which statement below is false? The RBC is hypertonic to the 0.5% solution Which is not a membrane protein function? Protein synthesis Ingesting (eating) excess hydrophilic vitamins, such as vitamin C, results in excess vitamin C being stored in your tissues. False Diffusion is: The movement of molecules from an area of high molecular concentration to an area of low molecular concentration across a selectively-permeable membrane The hormone responsible for glucose uptake/removal from the blood is: Insulin What method would you use to get sodium ions into a cell against sodium’s concentration gradient (from low to high concentration)? Active Transport Which phase of the cell cycle is where the cell is functioning normally or doing its job? Interphase Evidence for mitochondria once being bacteria that our cells engulfed is: It has it’s own DNA Ionic molecules (ie NA+, K+) can diffuse straight through the plasma membrane. True What is the difference between cis and trans fatty acids? Cis fatty acids have hydrogens on the same side of the carbon double bond and trans fatty acids do not Cofactors are molecules that activate enzymes. Where do we get cofactors from? Vitamins found in fruits and vegetables RNA has what nitrogenous base in place of thymine? Uracil Large polar molecules (ie glucose) can diffuse straight through the plasma membrane? False Which lipoprotein is comprised of more protein and less cholesterol so it scavenges for cholesterol in the blood? High density lipoprotein A normal human being has 46 chromosomes (23 pairs/2N/diploid) in each somatic cell (body cell). True The three main compounds digested by the digestive system are? Fats, carbohydrates, and proteins Meiosis is the process in which our sex cells go from 46 chromosomes to 23 single chromosomes. True The effector in any negative feedback loop is usually: An organ/tissue If a red blood cell is put into a solution and it crenates (shrinks), then the solution is considered to be: Hypertonic Which statement is false for glycogen? It is a disaccharide Enzymes aid in digestion by? Lowering the energy required to break food apart Nonpolar molecules (ie CO2) can diffuse straight through the plasma membrane

Telophase & Cytokinesis

Cell and Structures Cell vs. Viruses • Cells: Simplest living structures capable of performing all life functions independently. • Viruses: Non-living entities requiring a host cell to replicate and survive. Microscopes • Light Microscope: Uses visible light, magnifies up to 1,000x; resolution limited by wavelength of light. • SEM (Scanning Electron Microscope): Creates detailed 3D images of surfaces; does not show internal structures. • TEM (Transmission Electron Microscope): Produces high-resolution images of internal cellular structures. Magnification and Resolution • Magnification: Enlarges an object’s appearance. • Resolution: Measures the clarity of an image by distinguishing two points as separate. Robert Hooke • Coined the term "cells" after observing cork under a microscope. • Published his findings in Micrographia (1665), advancing the study of cells. Cytology and Biochemistry • Cytology: The study of cell structure and function. • Biochemistry: The study of chemical processes and substances within organisms. Cell Fractionation • A laboratory technique to break apart cells and isolate organelles for detailed study. Size Limitations of Cells • Smaller cells have a higher surface area-to-volume ratio, which is essential for efficient exchange of materials. Prokaryotes vs. Eukaryotes • Prokaryotes: No nucleus or membrane-bound organelles; simpler and smaller (e.g., bacteria). • Eukaryotes: Have a nucleus and membrane-bound organelles; larger and more complex. Cell Structures and Functions • Nucleus: Stores genetic material (DNA). • Plasma Membrane: Protects the cell; regulates material exchange. • Cytosol: Fluid portion of the cytoplasm where cellular processes occur. • Microvilli: Increases surface area for absorption in some animal cells. • Cytoskeleton: ◦ Microfilaments (actin): Provides structural support. ◦ Microtubules: Involved in transport and motility. • Animal Cell-Specific Structures: ◦ Desmosomes: Anchor cells together. ◦ Gap Junctions: Channels that allow communication between cells. ◦ Tight Junctions: Create a watertight seal between cells. • Extracellular Matrix (ECM): Nonliving material outside cells, providing structural and biochemical support. • Plant Cell-Specific Structures: ◦ Plasmodesmata: Channels connecting cytoplasm between plant cells. Cellular Respiration Definition • Process of extracting energy from glucose to produce ATP, the cell's main energy currency. ATP • Made by the enzyme ATP synthase, powered by hydrogen ion (H⁺) movement across the inner mitochondrial membrane. Three Stages of Respiration 1 Glycolysis (Cytoplasm): ◦ Reactants: Glucose. ◦ Products: 2 Pyruvate, 2 ATP (net), and NADH. 2 Krebs Cycle (Mitochondrial Matrix): ◦ Reactant: Acetyl CoA. ◦ Products: CO₂, NADH, FADH₂, and 2 ATP. 3 Electron Transport Chain (ETC) (Inner Mitochondrial Membrane): ◦ Reactants: NADH and FADH₂ (electron carriers). ◦ Products: Water and ~32-34 ATP. Key Points • No oxygen = no Krebs cycle or ETC; only 2 ATP are produced via glycolysis. • Fermentation occurs in anaerobic conditions: ◦ Converts pyruvate into lactic acid (in animals) or ethanol (in yeast). Photosynthesis Overview • Process where plants convert light energy into chemical energy (sugars). • Formula: CO2+H2O→O2+G3PCO_2 + H_2O \rightarrow O_2 + G3PCO2​+H2​O→O2​+G3P. Key Concepts 1 Light Reactions (Thylakoid Membranes): ◦ Products: ATP and NADPH (used in the Calvin Cycle). ◦ Oxygen is produced by Photosystem II. 2 Calvin Cycle (Stroma): ◦ Uses ATP and NADPH to fix carbon dioxide into G3P (a sugar precursor). Photosystems • Photosystem II: Produces oxygen and ATP. • Photosystem I: Produces NADPH. Adaptations • C4 Pathway: Spatial separation of steps to avoid photorespiration. • CAM Pathway: Temporal separation, stomata open at night to reduce water loss. Mitosis and Meiosis Mitosis • Division of a eukaryotic somatic (non-reproductive) cell into two identical diploid cells. • Phases: 1 Prophase: Chromosomes condense; spindle forms. 2 Metaphase: Chromosomes align at the cell's equator. 3 Anaphase: Sister chromatids separate. 4 Telophase: Nuclear envelopes reform. 5 Cytokinesis: Cytoplasm splits into two cells. Meiosis • Specialized cell division in germ cells (ovaries/testes) to produce gametes. • Key Features: ◦ Two divisions produce four genetically unique haploid cells. ◦ Crossing over occurs during Prophase I for genetic diversity. Binary Fission • A simple form of cell division in prokaryotes producing two identical cells. Genetics • Haploid: Single set of chromosomes (e.g., gametes). • Diploid: Two sets of chromosomes (e.g., somatic cells). • Punnett Squares and Pedigrees: Tools to predict genetic inheritance. Cell and Structures Cell vs. Viruses • Cells: Simplest living structures capable of performing all life functions independently. • Viruses: Non-living entities requiring a host cell to replicate and survive. Microscopes • Light Microscope: Uses visible light, magnifies up to 1,000x; resolution limited by wavelength of light. • SEM (Scanning Electron Microscope): Creates detailed 3D images of surfaces; does not show internal structures. • TEM (Transmission Electron Microscope): Produces high-resolution images of internal cellular structures. Magnification and Resolution • Magnification: Enlarges an object’s appearance. • Resolution: Measures the clarity of an image by distinguishing two points as separate. Robert Hooke • Coined the term "cells" after observing cork under a microscope. • Published his findings in Micrographia (1665), advancing the study of cells. Cytology and Biochemistry • Cytology: The study of cell structure and function. • Biochemistry: The study of chemical processes and substances within organisms. Cell Fractionation • A laboratory technique to break apart cells and isolate organelles for detailed study. Size Limitations of Cells • Smaller cells have a higher surface area-to-volume ratio, which is essential for efficient exchange of materials. Prokaryotes vs. Eukaryotes • Prokaryotes: No nucleus or membrane-bound organelles; simpler and smaller (e.g., bacteria). • Eukaryotes: Have a nucleus and membrane-bound organelles; larger and more complex. Cell Structures and Functions • Nucleus: Stores genetic material (DNA). • Plasma Membrane: Protects the cell; regulates material exchange. • Cytosol: Fluid portion of the cytoplasm where cellular processes occur. • Microvilli: Increases surface area for absorption in some animal cells. • Cytoskeleton: ◦ Microfilaments (actin): Provides structural support. ◦ Microtubules: Involved in transport and motility. • Animal Cell-Specific Structures: ◦ Desmosomes: Anchor cells together. ◦ Gap Junctions: Channels that allow communication between cells. ◦ Tight Junctions: Create a watertight seal between cells. • Extracellular Matrix (ECM): Nonliving material outside cells, providing structural and biochemical support. • Plant Cell-Specific Structures: ◦ Plasmodesmata: Channels connecting cytoplasm between plant cells. Cellular Respiration Definition • Process of extracting energy from glucose to produce ATP, the cell's main energy currency. ATP • Made by the enzyme ATP synthase, powered by hydrogen ion (H⁺) movement across the inner mitochondrial membrane. Three Stages of Respiration 1 Glycolysis (Cytoplasm): ◦ Reactants: Glucose. ◦ Products: 2 Pyruvate, 2 ATP (net), and NADH. 2 Krebs Cycle (Mitochondrial Matrix): ◦ Reactant: Acetyl CoA. ◦ Products: CO₂, NADH, FADH₂, and 2 ATP. 3 Electron Transport Chain (ETC) (Inner Mitochondrial Membrane): ◦ Reactants: NADH and FADH₂ (electron carriers). ◦ Products: Water and ~32-34 ATP. Key Points • No oxygen = no Krebs cycle or ETC; only 2 ATP are produced via glycolysis. • Fermentation occurs in anaerobic conditions: ◦ Converts pyruvate into lactic acid (in animals) or ethanol (in yeast). Photosynthesis Overview • Process where plants convert light energy into chemical energy (sugars). • Formula: CO2+H2O→O2+G3PCO_2 + H_2O \rightarrow O_2 + G3PCO2​+H2​O→O2​+G3P. Key Concepts 1 Light Reactions (Thylakoid Membranes): ◦ Products: ATP and NADPH (used in the Calvin Cycle). ◦ Oxygen is produced by Photosystem II. 2 Calvin Cycle (Stroma): ◦ Uses ATP and NADPH to fix carbon dioxide into G3P (a sugar precursor). Photosystems • Photosystem II: Produces oxygen and ATP. • Photosystem I: Produces NADPH. Adaptations • C4 Pathway: Spatial separation of steps to avoid photorespiration. • CAM Pathway: Temporal separation, stomata open at night to reduce water loss. Mitosis and Meiosis Mitosis • Division of a eukaryotic somatic (non-reproductive) cell into two identical diploid cells. • Phases: 1 Prophase: Chromosomes condense; spindle forms. 2 Metaphase: Chromosomes align at the cell's equator. 3 Anaphase: Sister chromatids separate. 4 Telophase: Nuclear envelopes reform. 5 Cytokinesis: Cytoplasm splits into two cells. Meiosis • Specialized cell division in germ cells (ovaries/testes) to produce gametes. • Key Features: ◦ Two divisions produce four genetically unique haploid cells. ◦ Crossing over occurs during Prophase I for genetic diversity. Binary Fission • A simple form of cell division in prokaryotes producing two identical cells. Genetics • Haploid: Single set of chromosomes (e.g., gametes). • Diploid: Two sets of chromosomes (e.g., somatic cells). • Punnett Squares and Pedigrees: Tools to predict genetic inheritance.

Telophase

Cell Division and Reproduction Asexual Reproduction Only 1 parent required for asexual reproduction. Fast and simple process. Results in identical offspring without genetic variation. Examples include binary fission in bacteria. Sexual Reproduction Involves 2 parents contributing to offspring. Offspring genetically different from parents. Slower and more expensive compared to asexual reproduction. Leads to genetic variation, aiding evolution in changing environments. Modes of Reproduction Asexual reproduction involves a single parent producing genetically identical offspring through binary fission. Example: Amoeba divides by binary fission to form daughter cells. Sexual reproduction requires two parents contributing to genetically diverse offspring. Genetic variation in sexual reproduction allows adaptation to environmental changes. Eukaryotic Cell Division Mitosis produces identical daughter cells for asexual reproduction, growth, and repair. Meiosis generates different daughter cells for sexual reproduction and gamete formation. Meiosis results in four unique daughter cells compared to two identical cells in mitosis. Cell Cycle and Mitosis Eukaryotic Cell Division Mitosis results in daughter cells identical to the parent cell. Occurs in asexual reproduction, growth, development, and repair. Meiosis produces daughter cells different from parents for sexual reproduction. Involves the formation of gametes like sperm and egg. Eukaryotic Chromosomes Chromosomes are tightly coiled DNA structures. Human cells (except gametes) typically have 46 chromosomes. Genes are specific DNA sequences on chromosomes. Chromatin, a looser DNA form, condenses into chromosomes before cell division. The Cell Cycle Ordered sequence of events from cell formation to division. Consists of interphase (cell growth and DNA replication) and mitotic phase (DNA and cytoplasmic division). Interphase includes G1 (cell growth), S (DNA duplication), and G2 (preparation for division). Stages of Mitosis Prophase: Chromosomes coil tightly, spindles form. Prometaphase: Nuclear envelope breaks, microtubules attach to chromatids. Metaphase: Chromosomes align at the cell's equator. Anaphase: Sister chromatids separate and move to opposite ends. Telophase: Chromosomes decondense, nuclear envelope reforms. Cytokinesis: Cytoplasm divides, forming two daughter cells. Mitosis and Cell Division Mitotic Spindle Microtubules that separate chromosomes during mitosis. Aids in pulling DNA to opposite ends of the cell. Essential for proper chromosome distribution. Ensures accurate division of genetic material. Mitosis Summary Results in two daughter cells identical to the parent cell. Utilized in asexual reproduction, growth, and repair. Mathematically, chromosome count doubles during S phase and halves after cytokinesis. Ensures genetic stability and continuity in cell populations. Comparing Binary Fission and Mitosis Both processes involve chromosome duplication and cell division. Mechanics and timing differ between bacterial binary fission and eukaryotic mitosis. DNA replication and separation occur simultaneously in binary fission, unlike in mitosis. Mitotic spindle formation is unique to eukaryotic cell division. Cancer and Cell Cycle Cell cycle checkpoints regulate cell division. Disruption of checkpoints, like the G1/S checkpoint, can lead to cancer. Tumors result from uncontrolled cell growth. Benign tumors stay localized, while malignant tumors can metastasize. Eukaryotic Chromosomes and Cell Cycle Chromatin and Chromosomes Chromatin organizes DNA into chromosomes before cell division. Gene: a sequence of nucleotides on a chromosome. Sister chromatids are duplicated chromosomes held by a centromere. The Cell Cycle Phases Interphase: cell growth and DNA replication stages. Mitotic Phase: includes mitosis and cytokinesis for cell division. Mitosis stages: Prophase, Prometaphase, Metaphase, Anaphase, Telophase.

1.3 Macro Intro Breaking a bond = hydrolysis Build/make a bond = remove water, dehydration synthesis 1.4 Macros Nucleic Acids DNA and RNA Made from nucleotides A, T, C, G, U Proteins Amino acids Polypeptide To make it into a protein you need to fold and modify Carbs Monosaccharides Ex. glucose Polysaccharides Ex. starch, cellulose, glycogen, chitin Lipids nonpolar Ex. phospholipids Saturated (butter) vs unsaturated (oil) 1.5 Macros structure + function Uses covalent bonds between nucleotides Main structure want it to be covalent bond so its strong Bases use hydrogen bonds DNA is antiparallel, equally spaced read in opposite directions Protein Primary - Amino acids Secondary - Pleats and coils (hydrogen bonding) Tertiary - Interactions between the R-groups (unique shapes) Quaternary - 2 or more chains (any bond) Carbs Chains of sugars using covalent bonds 1.6 Nucleic Acids DNA Deoxyribose sugar T Double stranded RNA Ribose sugar U Single stranded Common Both use nucleotides A, G, C U2 Cells Organelles Ribosomes = protein synthesis Found on rough ER or free Show common ancestry Endoplasmic Reticulum Rough = ribosomes Smooth = makes lipids, detox Golgi complex Protein trafficking Packaging and transport of proteins mitochondria Site of cellular respiration, ATP production Double membrane Own DNA circular DNA Chloroplast Site of photosynthesis Own circular DNA Lysosome Hydrolytic enzymes Apoptosis Vacuole Large in plants Small in animal cells 2.3 Cell Size Small cells Inc surface area to volume ratio More efficient Better for transportation, elimination of waste, heat, exchanges, etc 2.4 Plasma Membrane Small and nonpolar can pass through easily (oxygen and carbon dioxide) 2.5 Membrane Permeability Selectively permeable Transport proteins needed for larger polar molecules Cell wall - plants, fungi, and prokaryotes Provides extra support and protection 2.6 Transport Passive transport (high to low) Does Not require any energy Diffusion Osmosis Facilitated diffusion (uses proteins) Active transport (low to high) Require energy Exocytosis Moving things in or out Endocytosis 2.7 Facilitated diffusion Uses integral proteins Ex. aquaporins, ion channels, neurons Proteins also used for active transport 3.6 Cellular Respiration Glycolysis Within the cytoplasm Evidence of common ancestry because all organisms go through glycolysis Glucose to 2 pyruvates Energy investment phase and energy payoff phase Get pyruvate, ATP, and NADH Fermentation (ONLY IF NO OXYGEN) To reset everything Takes NADH and turns it back to NAD+ to keep running glycolysis Grooming Phase Modify and turn it into Acetyl CoA Kreb Cycle With in the matrix Making electron carriers (NADH and FADH2) Inner mitochondrial membrane Where the electron transport chain takes place 3.7 Fitness Max offspring Variation can increase fitness Unit 4 Cell Communications 4.1 Signal Transduction Pathway Autocrine (signal yourself) Paracrine (next to you) Endocrine (far from you) 4.2 Signal Transduction Pathway intro Reception → transduction → response Reception: ligand attacks to the receptor The process by which a cell detects a signal in the environment. Ex. ligand binds to G protein which activates Transduction: phosphorylation cascade and amplifies signal The process of activating a series of proteins inside the cell from the cell membrane. Response: The change in behavior that occurs in the cell as a result of the signal. Second messenger - first is ligand, second messenger is for amplification (cAMP - each can have their own phosphorylation cascades) 4.3 STP Responses Turn gene off/on Apoptosis Cell growth start/stop 4.4 changes to STP Mutations (respond too much or too little to the signal molecule attacking) Chemical can release that can interfere with your STP resulting with death 4,5 Feedback Respond to changes (homeostasis) Negative (reverse change) Positive (increasing the change) 4.6 / 4.7 Cell Cycle/ Regulation G1 - growth G1 checkpoint (determine if you go to S phase or to G0 non dividing state) S - DNA replication G2 - organelle replication and growth G2 checkpoint - make sure the cell is ready for division M phase - Mitosis PMAT Prophase - nucleus disappears Metaphase - lined up at the equator Anaphase - replicated chromosomes are split Telophase - move to opposite ends M-phase checkpoint - checks to make sure division is correct Cytokinesis - final split into 2 Cyclin increases during S and peaks at M Cdk binds with cyclin to produce mpf Level of cyclins lets cell know where it’s supposed to be Tells your cell you are at your full maturity ready to produce Unit 5 Heredity 5.1 / 5.2 Meiosis Increases genetic variation Crossing over (Prophase 1) Reduction division haploid (half the amount of genetic information) Random fertilization Nondisjunction (meiosis 1 all 4 cells are irregular / meiosis 2 half the cells are irregular) Independent Assortment Increases genetic diversity 5.3 Mendelian Genetics A = dominant allele a = recessive allele Genotype - combination of letters (AA, Aa, aa) Phenotype = looks Law of Segregation - Aa → A / a Law of Independent Assortment (Aa Bb → AB, Ab, aB, ab) Sex Linked Located on a sex chromosome Usually X Sex linked recessive is more common in males because they only have one X Sex linked dominant both can inherit easily Incomplete dominance - blending Codominance - both alleles expressed 5.5 Environmental Effects Ex. weather, pH of soil 5.6 Chromosomal Inheritance Mutation → inherited Some have no effect, negative effect, neutral effect, 6.1 Gene Expression and Regulation 6.1 DNA Double stranded Deoxyribose T RNA Ribose Single stranded U 6.2 Replication (S-Phase) 5’ → 3’ Ligase - binds the new bases together Helicase - unwinds the DNA DNA poly - put down the new bases Primase - makes primer Topoisomerase - stops DNA from getting overwind Leading - able to all go in one go Lagging - many primers and okazaki fragments 6.3 Transcription and Processing Nucleus RNA poly makes primary transcript (pre mRNA) from DNA Template strand is the one the DNA is using to build Non template strand one not being used RNA processing Introns are removed Exons are put together Add cap and tail for protection Alternative splicing 6.4 Translation Ribosome Reverse Transcriptase retroviruses Ex. HIV RNA genomes use reverse transcriptase to make DNA from RNA 6.5 Regulation of Gene Expression Signal to unpack the gene Transcribed (transcription factors differ by cells and allows different gens to turn on) RNA editing Translation Polypeptide folding All need to go correctly or else the gene wont be expressed Acetylation of histones - adding acetyl group causes the DNA to be more loose making it easier to read Methylation of histones - adding methyl groups to the DNA causes it to be tighter and harder to read Enhancers - enhances transcription and causes it to occur more often Activators - dont bind to RNA poly it binds to the enhancer Depends of which genes and stage of development Epigenetics - one gene controls another gene Inducible Operon - usually off Repressor is bound to operon and lactose inactivates Repressible Operon - usually on Repressor is usually inactive, trp activates repressor 6.6 Gene Expression and Cell Specialization Promoter region (TATA box) alerts RNA poly that its a promoter region and where to attach Negative regulation - blocks promoter so RNA poly cant attach small RNA - can turn certain genes off 6.7 Mutations Increase normal gene function Decrease normal gene function Can lead to new phenotypes Cancer can be due to overproduction of growth factors, hyperactive proteins (requires many mutations Can have positive, negative, or no effect Causes of mutation Exposures Random Errors in DNA replication Increase or decrease in chromosome number Prokaryotes Transformation - pick up random DNA Transduction - virus accidentally is filled with bacterial DNA Conjunction - mating bridge/sex pilus 6.8 Biotechnology Electrophoresis - separates DNA by charge and size PCR - artificial DNA replication, increases amount of DNA sample Transformation - you make the bacteria take up a gene you're interested in Unit 7 7.1 Natural Selection natural / selective pressures decide survival Reproductive fitness (max out your kids) 7.2 Natural Selection Acts on phenotypes which can affect genotype Preferring brown fur over white decreases white fur allele frequency Environmental changes → selective pressures 7.3 Artificial Selection Humans select (ex. Dogs, livestock, etc) Convergent evolution - not closely related but because of similar environments you look alike Divergent - had a recent common ancestor but you started becoming separate Niche partitioning - choosing separate niches so you dont have to compete with others 7.4 Population Genetics Mutation - variety and evolution Genetic drift - random event that alters the gene pool Bottleneck effect - an event causes a large part of the population to die off and the remaining left repopulate with a different gene pool Founder effect - the og are there but some leave/get separated 7.5 Hardy Weinburg Large population No natural selection Random mating No mutation No gene flow P+q = 1 p2 + 2pq +q2 = 1 (AA) + (Aa) + (aa) = 1 7.6 Evidence of Evolution Fossils DNA (molecular homologies) Anatomy Vestigial structure (things we dont need anymore) (evidence of common ancestry) Biogeography (species are found all around the world)(kangaroos, genetic code, glycolysis) 7.7 Common Ancestry All Eukaryotes Membrane bound organelles Linear DNA and chromosomes Genes with introns 7.8 Continuing Evolution Genomic changes over time Continuous changes in fossils Evolution of antibiotic resistance Disease evolution 7.9 Phylogeny / Cladistics Phylogeny = included time Cladograms = just traits Shared characters Derived characters Molecular (DNA, proteins, amino acids) are more accurate than characteristics Parsimony - the one with the fewer events on it, the frewer you have the more likely it is 7.10 Speciesation Pre-zygotic Mechanical - parts dont match Gametic - egg doesnt match Geographical - dont live in the same place Temporal - ready to mate at different times Behavioral - specific type of mating display is not there Post-zygotic Hybrid sterility - the hybrid made is healthy but they cannot have children (mule) Hybrid breakdowns - the hybirds are okay but after a generation or two they cannot produce anymore Hybrid inviability - hybrid is produced but cannot survive long enough to reproduce Sympatric New species arrises in the original location Gradualism - slow steady evolution Allopstric Separation leads to speciation Punctuated - long periods of evolution with no change then rapid change 7.11 Extinction Can be natural or human caused If something goes extinct it can open up opprotunities for other species 7.12 Variation Genetic diversity Diversity of the ecosystem = inc biodiversity Less likey to be 7.13 Origins of Life on Earth No oxygen on earth 4.6 billion No ozone layer Tons of UV radiation High ocean levels Vooacanic eruptions RNA was the first genetic material DNA is dependant of RNA in

telophase

B3.7.6 - Telophase

CH 11 Mitois: Cell Reproduction