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WGU C190 / BIOLOGY C190 INTRODUCTION TO BIOLOGY COMPLETE
COMPREHENSIVE STUDY GUIDE BEST FOR MIDTERM & FINAL EXAM
PREPARATION
Module 1:
1. What is an abiotic factor? Give examples. 2. What is a biotic factor? Give examples. Biotic : living/lived Abiotic : nonliving/never lived ****Characteristics of Life** There are five distinct qualities used to determine whether or not something is (or was) alive. A living organism is something that displays all these qualities. To be considered alive, something must: 1. Be made of materials organized in a hierarchical pattern. 2. Use energy and raw materials to survive (organisms) 3. Sense and respond to changing environments and maintain internal stability, or homeostasis. 4. Grow, develop, and reproduce. 5. Be part of a population that evolves.
- Atoms and molecules are not alive.
- Bacteria are unicellular microorganisms making them biotic. 3. List the biological levels of organization from atom to biome. Which levels are considered living? Why? Atom, molecule, macromolecule, organelle , cells, tissues, organs, organ systems, organisms, populations, communities, ecosystem, and biosphere. Anything before the cell is biotic. – “5 characteristics of life” **Module 2:
- How was the process of scientific inquiry used to determine if protein or DNA carried genetic information?** The Hershey and Chase experiment. Variables controlled: The types of cells used, the method for locating tagged molecules, the way that the molecules were tagged. Scientific Hypothesis: Has 3 essential elements.
- Makes a prediction
- Is falsifiable – one that can be shown to be incorrect.
- Is reproducible The hypothesis is the foundation of your experiment. There are three types of variables that can have effect on a scientific experiment. The independent variable , the dependent variable , and any confounding variables. The independent variable in an experiment is the factor that you are manipulating to see how it affects the dependent variable or the outcome. The dependent variable is quantitative. The confounding variable , is the one we want to try to control. Confounding variables are variables we are not testing for but might have an effect on the results and also could damage the validity of our experiment. Module 3: Atom : basic unit of matter, all atoms have protons, neutrons, & electrons. Protons & Neutrons in the dense nucleus surrounded by electrons, hydrogen ions, the building blocks of all matter, two or more atoms combined are a molecule. Maximum of 2 Electrons in 1st^ shell (valence electrons), 2- 4 th^ shell can have up to 8 electrons. Periodic Table: Atomic # @ top left corner of box (atomic # is same as # of protons), mass # is at bottom of box (mass # = protons + neutrons). Group #’ are across the top of table, give # of valence electrons. 1. Complete the table to describe the three types of subatomic particles: Protons: positively charged , this is one of the two subatomic particles that is located in the nucleus of the atom, mass 1 amu Neutrons: (Neutral) have no charge , one of the two subatomic particles that is located in the nucleus of the atom, 1 amu.
Electrons: negative charge , surround the nucleus of the atom in orbital shells , orbit outside nucleus in shells; shells fill following a specific pattern, the mass of an electron is so small compared to the other subatomic
4. Density: When water freezes, each water molecule is bound by hydrogen bonds to its neighbors. In liquid water, hydrogen bonds break and reform more often, and the water molecules are able to move in more closely. Because of this difference, water molecules in liquid water are more closely packed together than water molecules in solid water. Most substances get denser as they cool, but the density of ice is less than the density of liquid water - solid is less dense than liquid (causes the ice to form at the top of water, lakes, etc.). Solutions : mixtures of two or more substances. The substances are evenly distributed throughout the solution; this means that you can sample any part of the solution and the composition of the solution will be the same. Solvent : the component of the solution in the greatest quantity Solutes : the component(s) present in lower qualities Hydrophilic : Water loving; substances that will dissolve, ionic substances, split into positive and negative ions dissolve in water , polar molecules: surround charged particles, breaking them away and pulling them into the fluid Hydrophobic : molecules that do not dissolve in water , non-polar molecules. IE - oils and fats Module 5: Inorganic Molecules : water, oxygen, carbon dioxide, and ionic salts like sodium chloride Organic Molecules : any molecule that contains a carbon to hydrogen (C-H) covalent bond. C-H bonds, covalent bonds, modular, monomers --> polymers, - produced by living cells, found in large quantities. IE - Proteins, fats, DNA, and glucose Characteristics of Organic Molecules: All organic molecules have several common properties that help distinguish them from inorganic molecules:
- All organic molecules contain carbon atoms bonded to hydrogen (C-H bonds). Organic molecules also often contain oxygen, nitrogen, phosphorus, or sulfur.
- Atoms within organic molecules are connected by covalent bonds.
- Organic molecules are modular. Contain smaller organic molecules ( monomers) linked together to form larger organic molecules ( polymers ). Refers to the subunits that link together to form the molecule.
- Organic molecules are often associated with living things. However, it is possible for living things to produce inorganic molecules or for organic molecules to be produced artificially. 1. Complete the following diagram. Be sure to include at least two functions and two examples for each macromolecule. What common features do all macromolecules have? 1. All are essential for proper functioning of ALL living things 2. All built primarily of carbon, hydrogen, oxygen – but in different ratios. 3. All are organic / All function in a type of storage **Type of Macromolecule:
- Carbohydrates** : Essential for energy storage, cellular communication, and structural support. Organic molecules that consist of carbon, hydrogen, and oxygen atoms in a 1:2:1 ratio, most abundant, primary source of energy, provide quick energy access to plants and animals. They can store energy in the form of starch and glycogen, and they provide structural support. Are either simple sugars or complex sugars (complex carbs) **Simple sugars are made up of only one or two sugar monomers. A single sugar monomer is called a monosaccharide. Two sugar monomers bound together to form a disaccharide. Common, important monosaccharides are glucose and galactose. Lactose is an example of a disaccharide. Polysaccharides are complex carbohydrates made up of many sugar molecules or monosaccharides linked together. Starch is a common polysaccharide composed of many glucose monomers made by plants. Carbohydrates
Polymers: Macromolecules, Large molecules consisting of repeating structural units, or monomers, connected by covalent chemical bonds. Monomers : A small organic molecule that may bind chemically to other molecules to form a polymer. A monomer is a repeating structural unit of a polymer
**- Carbohydrates are polymers made up of sugars ( the monomers ). Proteins are polymers made up of amino acids ( the monomers ). Nucleic acids are polymers made up of nucleotides (the monomers ). Even lipids are generated by combining separate fatty acid chemical components. Monosaccharides : simplest sugars, glucose and fructose. A single sugar monomer. Disaccharides : Two sugar monomers bound together by a covalent bond Polysaccharides : complex carbohydrates made up of many sugar molecules or monosaccharides linked together. Long chains of monosaccharides bonded together. Often used for energy storage & structural support by organisms. Glucose : A simple carbohydrate (monosaccharide). The primary product (output) of photosynthesis & the primary reactant (input) of cellular respiration. Glucose in the form of simple sugar can also be used by the cell. Cells break apart glucose to release and use the energy inside. Glucose and other simple carbohydrates are quickly and easily accessed to generate energy the cell can use. 2. Lipids : Essential for energy storage and maintaining a boundary between the living organism and its environment, organic macromolecules that are largely nonpolar, resulting in hydrophobic. Store energy for long-term use in the form of fats, insulation from environment, & building blocks for hormones. “Macro” molecules composed of subunits of fats. IE – fats, oils, waxes, phospholipids, cholesterol, & steroids. Types of Lipids:
- Fats: A type of lipid composed of glycerol & saturated fatty acids. Typically, solid at room temperature. Used to store energy for later use provide structural support and cushioning for many animals.
- Oils: A type composed of glycerol & unsaturated fatty acids. Typically, liquid at room temperature. Fats and oils are also called triglycerides because they are made of three (“tri”) fatty acids attached to one glycerol.
- Phospholipids : structure to cell membrane , protective barrier surrounding the cell or separating compartments and forming organelles within the cell. Composed of fatty acids & phosphate. Phospholipids are hydrophilic and hydrophobic, which is different than other lipids which are completely hydrophobic. They contain only two fatty acids attached to a glycerol. Glycerol has a phosphate group attached to it. The phosphate group is the head group and fatty acids are the tail. The phosphate group carries a negative charge, which makes it hydrophilic. The tail group is composed of non-polar carbon chains and is considered hydrophobic. Phospholipids form a bilayer with the polar head groups facing out on each side to interact with water, while the tails are driven inward and pointing toward one another. This makes the lipid bilayer layer of cell membranes selectively permeable to certain molecules trying to enter and leave the cell.
- Steroids : Composed of carbon ring molecules. Many hormones and cholesterol are steroids. Are NOT used for energy in a cell.
- Waxes : forms a protective layer on plants and animals. Composed of Esters of fatty acids. nonpolar ** All lipids are more soluble in nonpolar solvents than in water. 3. Proteins: The most functionally diverse group of biomolecules, directly carries out most functions of the cell, play a role in the storage, replication, transmission, and regulation of DNA, help move substances in and out of the cell, transfer materials throughout the body, can facilitate mechanical movement, & help maintain structure to the body of an organism. Composed of folded chains of amino acids. The amino acids are attached end by end by covalent bonds. A long chain of amino acids is known as a polypeptide chain. The type and sequence of amino acids dictates the shape and function of the protein. One of the most important roles that proteins play is as enzymes ; they help speed up and control the chemical reactions occurring in cells.
5. In the picture above, B is Hydrophilic , meaning that it mixes well with water, while C is Hydrophobic , meaning that doesn’t mix well with water. **How does this structure allow the formation of the phospholipid bilayer in cellular membranes? (See Phospholipid info.) 6. What type of macromolecule is depicted in the image below? What is its function? Protein – see above Enzymes : Proteins that catalyze reactions, they have the ability to bind substrate in their active site and then chemically modify the bound substrate. converting it to a different molecule FLASHBACK TO MODULE 3 : The image below shows a glucose molecule. As all organic molecules, it contains carbon and hydrogen atoms. In this molecule, the electrons are shared between the carbon, hydrogen, and oxygen atoms. What type of chemical bond holds these atoms together? **Covalent Bond
- What varies about ATP from a DNA version of adenine?** The pentose sugars that they are made of are different (deoxyribose in DNA compared to ribose in ATP) and they contain different numbers of phosphates (three in ATP and only one in a DNA nucleotide). Also, DNA nucleotides aren't limited to solely being made using adenine bases, with guanine, cytosine and thymine also being options.
Module 7:
1. What is Cell Theory? States that all known living things are composed of one or more cells. All new cells are created by pre-existing cells dividing. The cell is the most basic unit of structure and function in all living organisms. 2. Prokaryotes vs. Eukaryotes
Organelles: a membrane-enclosed structure that fulfills some specialized function in the cell, carry out specialized tasks such as energy production, protein synthesis, reproduction, and processing of nutrients and waste, most organelles are found in the cytoplasm. Mitochondria : take fuel in the form of glucose and converts it to usable ATP, produce most of the cellular ATP needed to power the body’s energy needs. Chloroplasts : organelles in eukaryotic cells able to harvest solar energy to make sugars from carbon dioxide, organelle, not found in animal cells, is responsible for generating sugar molecules. Chloroplasts in plant cells are the site of photosynthesis. Endoplasmic Reticulum (ER): lipids and proteins are synthesized. A series of sacs and tubes. 2 types of ER :
1. Rough ER has ribosomes embedded in it , giving it the beaded appearance that led to its name, assists the ribosomes in protein production, modifying and packing the proteins after the ribosomes produce them. 2. The smooth ER (without ribosomes ) can have different functions depending on the cell such as lipid production Golgi : packages and ships materials within and out of the cell, where the proteins built by ER are delivered to different parts of the body Lysosome: responsible for cellular digestion, also recycle cellular parts and destroy external invaders. Membrane-bound organelles that contain digestive enzymes that break down proteins, lipids, carbohydrates, and nucleic acids. They are important in processing the contents of vesicles taken in from outside the cell. 3. Organelles of Eukaryotes 4. Plant vs. Animal Cells
a. Describe things in common in Animal cells and Plant cells. Both are eukaryotic cells. b. There are the specialized structures in Plant cells only. List the names with the letters in the figure and describe the functions. A – Cellulose Cell Wall: Porous structure that protects, supports, and gives shape to the cell. In plants, the cell wall is made of cellulose, which is a complex carbohydrate that is very durable. Many organisms, including humans, cannot digest cellulose, but it is an important component of the fiber in a person's diet. Bacteria have cell walls and human cells do not , thus, antibiotics target the cell wall. B – Permanent Vacuole: Found in the cytoplasm of eukaryotic cells. specialized mainly for storage (large amounts of water), membranes do not fuse with the membranes of other cellular components. C – Chloroplast: organelles in eukaryotic cells able to harvest solar energy to make sugars from carbon dioxide, organelle, not found in animal cells, is responsible for generating sugar molecules. Chloroplasts in plant cells are the site of photosynthesis. c. What is the organelle existing only in Animal cells? Lysosome: responsible for cellular digestion, also recycle cellular parts and destroy external invaders. Membrane-bound organelles that contain digestive enzymes that break down proteins, lipids, carbohydrates, and nucleic acids. They are important in processing the contents of vesicles taken in from outside the cell. FLASHBACK: How does knowing the basic features common in ALL cells help differentiate between the Biotic and Abiotic components (Unit #1) of our planet? Module 8:
1. What is the function of the cell membrane? The boundary of the cell; it determines what enters and exits the cell, and it is how the cell interacts with its environment. The membrane also has other components, including carbohydrates, that can act as signaling molecules or markers to help the cell interact with its environment. All of these components float in the sea of phospholipids to make up the fluid membrane. **All Organelles have a membrane made out of same material. Phospholipid: Primary component of all cellular membranes , the fabric of the membrane. Acts as a barrier and helps a cell control what goes into and out of the cell. Has 2 parts – “phosphor” = phosphorus & lipid. *The fatty acid (lipid) tails point away from the water when they are inside the membrane layers – Hydrophobic *The phosphorus heads face the water – Hydrophilic Selectively Permeable : The cell membrane is selective/semi-permeable. Only certain substances are able to pass through the membrane by means of active or passive transport. Small, nonpolar molecules cross the membrane easily. 2. Associate the letters in the diagram below with the terms on the right.
1. What characteristics of a molecule determine its ability to pass through a membrane? A molecule’s SIZE and POLARITY determine its ability to move through the cell membrane. 2. Complete the following table. Mechanism of transport Active (requires energy) or Passive (does not require energy) Describe the substances transported in this way. (i.e. large or small, polar or nonpolar) Moving from high to low concentration or from low to high? Simple diffusion Facilitated diffusion Active transport Osmosis Simple Diffusion : Spontaneous movement from high to low concentrations, no use of energy, reach equilibrium, faster in warmer temperatures, moves slower in dense material. Molecules such as water, oxygen, and carbon dioxide are able to cross the cell membrane following their concentration gradient and using simple diffusion. Small polar & nonpolar molecules pass freely. Facilitated Diffusion : high to low concentrations, type of simple diffusion, aided by specific transport proteins. The process of moving impermeable molecules across a membrane using channels or pores, large polar and charged molecules. Active Transport : non-spontaneous process, from low to high against the concentration gradient, uses ATP and a transport protein. Osmosis : The diffusion of water across a semipermeable membrane (in response to an imbalance of a solute). 3. Compare and contrast endocytosis and exocytosis. Endocytosis : The moving of materials inside to the cytoplasm of a cell via vesicles or vacuoles. Exocytosis : The moving of materials out of the cytoplasm of a cell via membranous vesicles or vacuoles. Module 10: **The principal source of energy for all organisms on earth is the sun. ?? 1. All living organisms use the molecule GLUCOSE as a direct energy source in their cells. During PHOTOSYNTHESIS , energy from the SUN is converted into the energy carrier ATP and the electron carrier NADPH in the LIGHT DEPENDENT reaction. Then, this energy is used to produce GLUCOSE in the CALVIN cycle. During cellular respiration, energy stored in the GLUCOSE we eat is extracted and used to convert ADP into ATP through a reaction called phosphorylation. The ATP generated is then used to power cellular activities such as and. Photosynthesis: A metabolic pathway that uses light energy to build carbohydrates from carbon dioxide. This light energy is absorbed by photosynthetic organisms such as plants and algae and is used to convert carbon dioxide (CO 2 ) to glucose and oxygen. 1. Light-dependent reaction: The first step of photosynthesis, Oxygen is the biproduct. Phosphorylation: A chemical reaction in which a phosphate is added to another molecule. IE – ADP is phosphorylated to form ATP. The process requires an input of energy, which light energy and the light- dependent reaction can provide.
2. Calvin cycle (Calvin-Benson cycle or light-independent reaction): The second step of photosynthesis , the set of chemical reactions that take place in chloroplasts during photosynthesis. The cycle is light independent because it takes place after the energy has been captured from the sunlight. In this step, the plant uses the energy from ATP and the electron from NADPH to build sugars out of CO 2. The overall equation for the Calvin cycle is ATP + NADPH + CO 2 → Sugar. Produces the molecule ADP (a product of the Calvin cycle). Glucose: A simple carb (monosaccharide). This is the primary produce (output) of photosynthesis & the primary reactant (input) of cellular respiration. Humans (and all other organisms, including plants) use glucose as food, and release the energy in glucose through a process called cellular respiration. Is a six-carbon sugar. 2. Which organisms perform photosynthesis? Plants, algae, and cyanobacteria carry out photosynthesis. Plants are the main photosynthetic producers on land. Most algae are single-celled and microscopic, but some seaweeds can grow to be very large. Cyanobacteria often become very abundant in polluted waters, turning lakes and ponds “pea soup” green. 3. Where does photosynthesis take place in the cell? Chloroplasts: The organelle in eukaryotic cells where photosynthesis occurs (the main site). The process that converts energy from the sun into chemical energy & generally involves chlorophyll. Also, where the light- dependent reaction occurs. Surrounded by its own membrane, bacteria like, contains its own DNA, & is a singular circular organism. 4. Which pigment molecule absorbs light energy during the light-dependent reaction? Chlorophyll: The most common pigment, a plant pigment used to absorb light energy for photosynthesis, gives plants the green color because it absorbs red & blue light very well & reflects green light. Plants are able to use chlorophyll and other pigments to capture the sun's energy and use it to build the sugar molecules. 5. What is the overall chemical reaction for photosynthesis? CO2 + H2O + LIGHT →SUGAR + O (Inputs) (Outputs) **CO 2 supplies carbon for building sugar. Water is a source of the hydrogen atoms that are required for the process. Light supplies energy that can be captured in chemical form. 6. What is the role of NADPH during photosynthesis? NADPH: An electron carrier molecule produced in the light dependent reactions of photosynthesis. It is transferred to the Calvin Cycle where electrons are used to generate glucose. This molecule moves an electron from one reaction to another. NADPH will move the electron that started in water to the next step of photosynthesis, which is where it will be used to make sugars. 7. Examine the diagram of photosynthesis and label the symbols in the key below:
2. Krebs cycle (citric acid cycle): The 2 nd^ step of aerobic cellular respiration that occurs when Acetyl coA combines with a 4 - carbon molecule, & goes through a cycle of reactions, producing ATP, NADH, FADH2, & CO2. ▪ NADH: An electron carrier molecule produced in glycolysis & Krebs Cycle. Used in cellular respiration, which is also produced in glycolysis. It is transferred to the electron transport chain where the electrons are used to generate ATP. ▪ FADH2: One of the electron carriers produced in the Krebs Cycle of aerobic cellular respiration. It is transferred to the electron transport chain where the electrons are used to generate ATP. ** NADH and FADH 2 are molecules that provide the transport of high-energy electrons from one step of cellular respiration to another. 3. Electron transport chain: The last stage of aerobic cellular respiration where the NADH & FADH deposit their electrons. As the electrons move down the chain, energy is released & used to move protons across the mitochondrial membrane & produce ATP. At the end of this process, oxygen acts as the final electron acceptor to form water. Requires oxygen. Mitochondrion: Organelle used in cellular respiration. 1. Which molecule is the direct source of energy for nearly all cellular activities? Give two examples of cellular activities powered by the energy in this molecule. ATP : (T=Tri Phosphate) excellent short-term energy carrier molecule and is used for almost all the energy needs of the cell, one of the cell’s energy stores. Small organic molecule with 3 phosphate groups attached that acts as a direct source of energy for almost all cellular activities. Relatively unstable, so never used for long- term storage of energy. Generally used for direct & rapid transfers. ATP is built through phosphorylation of ADP. ATP powers most of the energy-consuming activities of cells, such as: ▪ Most anabolic reactions. ... ▪ active transport of molecules and ions. ▪ nerve impulses. ▪ adding phosphate groups (phosphorylation) to many different proteins, e.g., to alter their activity in cell signaling. 2. Examine the image below. The P’s represent phosphate groups. Identify the input(s) and output(s) for Reaction 1 and Reaction 2. Indicate which statements are true for Reaction 1 and Reaction 2: Reaction 1 releases energy from the input(s) Reaction 2 is called phosphorylation Reaction 2 requires an input of energy Reaction 1 stores energy in the output(s) 3. Identify two sources that provide cells with the energy used to make ATP, and then identify the process that converts each energy source into ATP. fats, proteins, and carbohydrates. Cellular Respiration.
4. What is the overall chemical reaction for cellular respiration? Glucose + 6O 2 → 6H 20 +C0 2 + energy (ATP) 5. What is the role of electron carriers in cellular respiration? See NADH & FADH Identify each electron carrier in the reactions below: GLUCOSE → Glycolysis - NADH → ETC → ATP PYRUVATE + ACETYL CoA → Krebs Cycle → NADH + FADH2 → ETC → ATP + WATER 7. Identify which step of cellular respiration is described by each statement below. Each statement could describe one or more steps. 1. Glycolysis 2. Krebs Cycle 3. Electron Transport Chain Gas is an input Gas is an output Produces the most ATP Occurs in the cytoplasm Occurs in the mitochondria Occurs in aerobic conditions Occurs in anaerobic conditions Electron carrier(s) are inputs Breaks down sugar or sugar by-products Electron carrier(s) are outputs 8. Fermentation is an ANAEROBIC process, which means it occurs in the absence of OXYGEN. Under these conditions, GLYCOLYSIS produces two PYRUVATE molecules, which remain in the CYTOPLASM and proceed through fermentation. While fermentation is useful under anaerobic conditions, it produces much less ATP than the AEROBIC process of **CELLULAR RESPIRATION.
- Name the two types of fermentation and give an example of how each is used. Lactic acid fermentation:** In lactic acid fermentation, the two molecules of pyruvate are broken down into lactic acid. This is the type of fermentation that occurs in human muscle cells when oxygen levels are low such as during periods of intense exercise and the soreness you feel in your muscles after a workout is the result of this lactic acid buildup in your cells. It can also be used to produce many fermented food products such as kimchi and sauerkraut. Alcohol fermentation: It breaks the two molecules of pyruvate down into ethanol and carbon dioxide. It is the process used by yeast to create products such as beer, wine, cheese, and bread. While fermentation does not produce as much ATP as cellular respiration, it does allow cells to continue generating ATP when oxygen is unavailable, and it is used to produce many of the tasty foods we enjoy! FLASHBACK TO MODULE 1: Within each statement below (a – d), you will find four levels of biological organization. Identify each level and order the levels from the smallest to the largest. a. A human inhales oxygen from the environment, which is carried from the nasal passages, down the trachea, and into the lungs. b. Hemoglobin is a large protein found in red blood cells that carries oxygen throughout the body.
5. Cytokinesis : separates the nuclei into two new cells, the cytoplasm and membrane of the parental cell is split in order to form two daughter cells. B. Steps 1 – 3 (represented by the black line) are included in this phase overarching INTERPHASE. C. What is a chromosome made of? Use the following terms to label the image: DNA, nucleotides, gene, centromere, histone protein. (Flashback to module 6 for a reminder about nucleotides) D. What are the jobs of the histones, centromere, and gene? Chromosome: Tightly coiled form of the DNA-protein complex, thread-like structures located inside cells. Chromosomes are made up of two major parts: DNA and proteins called histones. Centromere: A specific section of the chromosome where spindle fibers attach during cell division. Also the connection point of Sister Chromatids. Joins the two halves of the chromosome together. Histones: Small proteins found along the length of chromosomes that can move closer or farther apart to help chromosomes contract into chromatin during cell division, used to support winding and unwinding of the DNA depending on what the cell’s needs are. E. Label the image to indicate homologous chromosomes and sister chromatids? What is the difference between them? Homologous chromosomes: Contain the same set of instructions (called genes). IE, there are genes that control hair color, height, blood type, etc. However, each of these chromosomes can have different specific versions (or alleles) of these genes. IE, one chromosome may have a gene coding for dark hair while the other has a gene coding for light hair. Sister chromatid: Arise due to the replication of DNA; they are exact copies of each other.
F. When would a chromosome become a chromosome composed of a pair of sister chromatids? Chromatid: Each copy of the chromosome is called a chromatid. The two chromatids are attached at the centromere to form a chromosome. Because the two chromatids are identical, they are called sister chromatids. G. Label the names of the stages and what a chromosome inside the cell would look like at each stage (condensed or not condensed, replicated or unreplicated). H. What is the difference between haploid and diploid cells? Diploid: In each of your cells, you have two copies of each of your chromosome: one copy from each parent. That status of having two copies of each chromosome is called diploid. Haploid: A haploid cell can have chromosomes with sister chromatids, but it will not have homologous chromosomes. Which event occurs to change a haploid cell to a diploid cell? Fertilization produces a diploid cell from two haploid cells. ****** Meiosis changes a diploid cell to a haploid cell. What is the difference between the chromosomes in a diploid cell and sister chromatids? Sister Chromatids are exact DNA replications. Diploid cells are copies from each parent. I. For Henrietta, which cells of her body were haploid and which were diploid? (Flashforward – if you are struggling with this concept, you might want to revisit it after completing modules 13 and 14).
- You can read more about Mrs. Henrietta Lacks here: https://en.wikipedia.org/wiki/Henrietta_Lacks
