STM 123 Biology 1 Midterm Reviewer PDF

STM 123 (General 1833 The center of the cell seen - Robert Brown, an...

STM 123 (General 1833 The center of the cell seen - Robert Brown, an English botanist Biology 1) REVIEWER - Discovered the nucleus in plant cells. FOR MIDTERM 1838 Basic building - Matthias Jakob blocks Schleiden EXAMINATION - All plant tissues are composed of cells, and that cells are the basic building blocks of all plants. Unit 1: The Cell 1839 Cell theory - Theodor Schwann, a German botanist. Lesson 1: Eukaryotic and - Cells are organisms and all organisms Prokaryotic consist of one or more cells - The cell is the basic unit of structure for all ABOUT CELL organisms ➔ Cells are the basic structural and 1840 Where does life - Albrecht von functional unit of life. come from? Koelliker - Discovers that sperm ➔ There are two major divisions into and eggs are also cells. which all cells fall, the prokaryotic and eukaryotic. 1845 Basic unit of life - Carl Heinrich Braun - Calling cells the basic ➔ Prokaryotic cells are cells that lack unit of life. a nucleus and membrane-bound 1855 3rd part to the - Rudolf Virchow, a organelles. Ex: Bacteria cell theory German ➔ Eukaryotic cells are cells that added physiologist/physician/p contain a nucleus and athologist - Omnis cellula e membrane-bound organelles. Ex: cellula. This translates Animal cells, plant cells, fungi. as “all cells develop only from existing A. Postulates of Cell Theory cells.” 1. Cells are the basic unit of life. - First to propose that 2. All things are made up of cells. diseased cells come from healthy cells. 3. All cells come from pre-existing Table 1.1. Cell Theory Timeline cell. B. Timeline of the cell theory C. Prokaryotic Cell ➔ Prokaryotic cells are cells that lack a Date Event Description nucleus and membrane-bound organelles. 1665 Cell first - Robert Hooke, an a. Parts and Function observed English scientist, - Honeycomb-like PARTS FUNCTIONS structure in a cork slice Capsule - Outer gelatinous covering. - Only saw cell walls and - Adhering to surfaces. dead tissue - protection against host - He coined the term immune responses "cell" 1670 First living cells - Anton van Cell wall - Provides protection, seen Leeuwenhoek structural support, and - looks at pond water maintains cell shape. with a - composed of microscope peptidoglycan. 1683 Miniature - Anton van Plasma - controls the passage of animals Leeuwenhoek Membrane organic molecules, ions, - The first protozoa and water, oxygen, and wastes bacteria into and out of the cell. discovered. - It is involved in energy generation and cellular 1  processes such as membrane proteins. Virtually, all respiration and bacteria and archaea also have a photosynthesis cell wall that surrounds the cell Nucleoid - Region where DNA is membrane. chromosomes are located. - Not membrane-bound - contains the genetic Features Gram-Positive Gram-Negativ information necessary for Bacteria e Bacteria cell growth, survival, and reproduction. Structure - Thicker - Thinner peptidoglycan peptidoglycan Chromoso - The main genetic material layer; no outer layer mal of the cell, located in the membrane - Outer DNA nucleoid. membrane - It is typically a single, containing circular, double-stranded lipopolysacchari DNA molecule that contains des (LPS), which most of the genes required can for the cell's functions. induce strong immune Plasmid - Small, circular, responses. DNA double-stranded DNA molecules. Cell Wall - Several layers - Single layer of - Provide Antibiotic Composition of peptidoglycan resistance. peptidoglycan. surrounded by - Can be transferred outer membrane. between cells and are not identical with the Gram-Staining - Retain the - They appear Chromosomal DNA.. purple crystal red/pink after violet dye staining. Cytoplasm - gel-like substance inside - They appear the cell membrane that purple/blue. contains water, enzymes, nutrients, wastes, and Table 1.3. Gram-positive vs gram-negative bacteria gasses. - The site of many metabolic E. Eukaryotic cells reactions. - Contains ribosomes and the ➔ Eukaryotic cells are cells that nucleoid region. contain a nucleus and Ribosomes - Composed of RNA and membrane-bound organelles. proteins that synthesize proteins by translating Parts and Functions of Eukaryotic messenger RNA. b. Cytoskelet - A network of protein on filaments that helps PARTS STRUCTURE/FUNCTIONS maintain the cell's shape. - secures DNA in specific Nucleus - Large, positions and assists in cell membrane-bound division and intracellular organelle surrounded transport. by a double membrane with pores, nuclear Flagella - Long, whip-like structures envelope, nuclear are used for cellular pores, chromatin, locomotion. nucleolus - Houses chromosomes Pili - Hair-like appendages on (DNA and proteins), the surface of the cell that contains nucleoli help with attachment to (ribosome surfaces (fimbriae) production), regulates - The transfer of DNA entry and exit of between bacteria during materials via pores. conjugation (sex pili). Nucleolus - Located inside the Table 1.2. Parts of a prokaryotic cell nucleus, it disappears during cell division. - Makes ribosomes that D. Gram-positive vs gram-negative make proteins. cell wall ➔ The cell membrane is also called the Nuclear - Double membrane Envelope surrounding the plasma membrane, which consists nucleus. of phospholipid bilayer and - Contains nuclear pores, 2  regulates the flow of Vacuole - Large, materials in and out of membrane-bounded the nucleus. vesicle. - For digestion, storage, Nuclear Pore - Openings in the waste disposal, water nuclear envelope. balance, cell growth, - Where materials enter and protection. and leave the nucleus. Mitochondrio - Double Chromatin - DNA spread out in n (s) membrane-bound non-dividing cells. Mitochondria organelle with inner - Forms chromosomes (p) folds (cristae). during cell division. - Outer membrane, inner membrane, cristae, Ribosome - Large and small matrix. subunits, rRNA, - ATP generation proteins. through cellular - Protein synthesis, it respiration. can be free in cytosol or bound to the ER. Chloroplast - Double membrane-bound Endoplasmic - Network of organelle with internal reticulum membranous tubules thylakoid system, and sacs. contains chlorophyll. - Photosynthesis, Rough ER - Has ribosomes on its converting light energy surface. to chemical energy. - Proteins are made by ribosomes on the ER Cytoskeleton - Network of protein surface, then modified fibers. and transported - Maintains cell shape, within ER. provides mechanical support, enables cell Smooth ER - Lacks ribosomes. motility (movement), - Makes membrane lipids and intracellular (steroids), regulates transport. calcium (muscle cells), destroys toxic Plasma - Phospholipid bilayer substances (H2O2) in Membrane with embedded the liver. proteins. - Selective barrier Golgi - Cis and trans faces. regulating what Apparatus - Modifies, sorts, and enters and exits the packages molecules cell. from ER for storage or transport out of the Cell Wall - Rigid layer outside the cell. plasma membrane. - contains -cis and -trans - Cellulose (in plants), faces chitin (in fungi), peptidoglycan (in Secretory - Small vesicles. bacteria). Vesicles - Transport cargo to - Provides protection specific sites at the and structural membrane for release. support. Cytoplasm - Jelly-like substance. Centrioles - Paired structures near - Provides a medium for nucleus in animal cells. chemical reactions to - Appear during cell take place. division, helping pull chromosome pairs Peroxisome - Small, apart. membrane-bound organelle containing enzymes. - Breakdown of fatty F. Plant and Animal Cells acids, detoxification of alcohol and Animal BOTH Plant cells harmful substances. cells Lysosome - Membranous sac No Cell Wall Nucleus Contains Cell containing hydrolytic Wall enzymes. - Breakdown of No chloroplast Mitochondria Contains ingested substances chloroplast for recycling. 3  Have many Cell Membrane Contains a ➔ Much longer and less small vacuoles large central uniform in length. (some with no vacuole ➔ Do not exhibit the true vacuoles) characteristics of cilia or Nucleus is Cytoplasm Have definite flagella present at the shape center of cell ➔ lack the 9+2 arrangement of microtubules. Contains Endomembran Nucleus is ➔ Increase the surface area for lysosomes e system pushed to one side of the cell absorption. ➔ Found in sensory cells of the Contains Ribosomes Cell Wall centrioles near maintains the ear (hair cells) and male the nucleus structure of the reproductive tract plant cells (epididymis and vas Irregular in deferens). shape C. Cilia Table 1.4. Plant and animal cells ➔ Motile or non-motile ➔ Appear as short hair-like G. Cell Modifications structures or projections. ➔ Apical Modifications (top) = cell ➔ Each cilium is connected to modification is found on the top a basal body and extends surface of the cell. from the free surface. ➔ Basal Modifications (bottom) = cell ➔ Core composed of modification is found on the bottom microtubules arranged in a surface of the cell. 9+2 pattern. ➔ Lateral Modifications (sides) = cell ➔ Beats in a coordinated modification is found on the sides of rhythmic wave-like the cell. movement to move materials over the surface. 1. Apical Modifications ➔ Moves mucus and trapped A. Microvilli particles in the respiratory ➔ Brush/ striated tract; moves the ovum in the ➔ Numerous, are often Fallopian tube. regularly arranged, and ➔ Lining of the trachea found in absorptive epithelia. (windpipe), Fallopian tubes, ➔ Finger-like cytoplasmic and other areas where extensions of the apical material needs to be moved surface. across the cell surface. ➔ Covered with a plasma D. Flagella membrane and often coated ➔ Unlike cilia, eukaryotic with a glycocalyx (fuzzy cell flagella are typically longer coat). and found singly. ➔ 9+2 arrangement of ➔ In prokaryotes, flagella have microtubules a different structure and ➔ Increase surface area for mechanism of action absorption. compared to eukaryotic ➔ Present in cells lining the flagella. small intestine and kidney ➔ Same axial structure as cilia tubules. but much longer. B. Steoreocilla ➔ Composed of a 9+2 ➔ Non-motile, long, and arrangement of branched extensions. microtubules. ➔ Important for signal ➔ Usually singular or in pairs. transduction in sensory cells. ➔ The base is anchored by a basal body. 4  ➔ Propels cells through fluid A. Tight Junctions (Zonula environments using a Occludens) whip-like motion. ➔ Appears to be fused, with a ➔ Present in the tail of 15-20 nm space between spermatozoa. epithelial cells. ➔ Barrier that prevents the passage of materials between cells. ➔ A band near the apical surface that forms a seal between epithelial cells. ➔ Composed of transmembrane proteins like claudins and occludins. ➔ Separates the Figure 1.1. Structure of microvilli, stereocilia, and cilia compartments, maintaining the distinct composition of 2. Basal Modification apical and basolateral A. Basal Infoldings membranes. ➔ Often associated with ➔ Found in epithelial cells, numerous mitochondria, particularly in tissues where suggests active transport. a barrier is needed, such as ➔ Deep invaginations of the the intestines and basal plasma membrane. blood-brain barrier. ➔ Increase surface area for B. Adhering Junctions (Zonula active transport, support Adherens) epithelial polarization and ➔ Found just beneath the tight stability. junction. ➔ Epithelium known to ➔ Maintain cell integrity and transport fluids, such as in adhesion. the kidney. ➔ Composed of actin B. Hemidesmosome filaments and associated ➔ Provide strong adhesion proteins like cadherins. between epithelial cells and ➔ Maintain the structural the basement membrane. integrity of cells and provide ➔ Protein filaments interlock, a strong mechanical cytoplasmic face connected ➔ Attachments between to microfilaments adjacent cells. (intermediate filaments), ➔ Found in epithelial and contains integrins. endothelial tissues, just ➔ Ensure structural integrity below tight junctions. and stability of epithelial C. Desmosome (Macula tissues. Adherens) ➔ Stratified epithelia like the ➔ Protein filaments interlock skin, mouth, and esophagus with filaments of adjacent of mammals. cells, forming a dense intermediate line. ➔ Junctions that help resist shearing forces. ➔ Provides mechanical strength to tissues. ➔ Composed of desmogleins and desmocollins, 3. Lateral Modifications 5  connected to intermediate filaments. ➔ Help resist mechanical stress and maintain tissue integrity. ➔ Found in tissues subjected to significant mechanical stress, such as simple and stratified squamous epithelium, skin, and cardiac muscle. D. Gap Junctions ➔ Adjacent cells are 2-3 mm Figure 2.1. Mitosis vs Meiosis apart. ➔ Junctions that facilitate cell B. Cell Division and Mitosis communication. ➔ Before cell division or the mitotic ➔ Made up of Connexons phase, the cells first go through a from Connexins. series of precisely timed and ➔ Allow direct regulated stages of growth, DNA communication between replication, and cell division that cells through the transfer of produce two identical cells. ions,nutrients, and other ➔ Two major phases of the cell cycle: small molecules. Interphase and Mitotic Phase. ➔ Found in various tissues, ➔ During Interphase, the cell grows including cardiac and and DNA is replicated, in smooth muscle, nerves, and preparation for cell division. some epithelial tissues. ➔ During the Mitotic Phase, the replicated DNA and cytoplasmic contents are separated and the cell divides. Lesson 2: Cell Division A. Cell Cycle ➔ Sequence of events involving cell growth and division that describes Figure 2.2. Cell Division the stages of a cell’s life from the division of a single parent cell to the a. Interphase production of new daughter cells. ➔ DNA is uncondensed. ➔ Mitosis: results in identical daughter ➔ Divided into 3 stages: G1, S, cells that are genetically identical to and G2. the parent cell. Gap 1 (G1) - Cells grow in size. ➔ Meiosis: results in unique haploid Phase - Rapid growth and metabolic activity. - Organelles are replicated; daughter cells containing only half mitochondria and ribosomes are of the chromosomes of the parent duplicated. cell. Synthesis - DNA is replicated so that each (S) Phase daughter cell receives a complete 6  set of genetic information. mitosis. - Proteins associated with DNA are synthesized. 4 During anaphase, the cyclin component of - Proteins necessary for DNA the MPF starts to degrade. packaging (e.g., Histone) are synthesized. If the cyclin component does not degrade, the cell cycle will stall and the cell will Gap 2 (G2) - Synthesis of proteins necessary for remain in the same phase. This might cause Phase the upcoming process of mitosis. cancer cells as well. - Double checks the replicated chromosomes, ensuring accuracy of 5 Back to G1, the degradation of cyclin DNA replication. continues and the CDK component is - Repairs errors to maintain genomic recycled. integrity before proceeding to Table 2.3. Cyclin-CDK components and cycle mitosis. Gap 0 - also known as the resting state. b. Mitotic Phase Phase - cells are not actively dividing, Cells may remain in this phase indefinitely ➔ Mitosis, also called or may re-enter the cell cycle. Karyokinesis, is divided into a series of phases that result in *Cell can undergo apoptosis is cell failed to repair problems in cell cycle the division of the cell nucleus. Table 2.1. Three stages of interphase ➔ Throughout the cell cycle, there are also 3 checkpoints: G1, G2 and Metaphase Checkpoints. G1 - Towards the end of G1. Checkpoint - Checks for nutrients, growth factors, and DNA damage. - When necessary nutrients are lacking, cells go through a resting state called G0. G2 - Towards the end of G2. Checkpoint - Checks for cell size and DNA replication. Figure 2.3. Stages of the mitotic phase Metaphase - During Metaphase in Mitosis. Checkpoint - Checks for chromosome spindle attachment. Prophase - DNA (chromatin fibers) condense Table 2.2. Three checkpoints of cell division and become visible under a microscope. - Nuclear membrane disintegrates. ➔ Cyclins are a group of proteins - Nucleoli disappear. that control progression of the - Mitotic spindle begins to form. - Centrosomes move apart from cell cycle. each other. ➔ CDKs are a family of protein Metaphase - Chromosomes align along the kinases involved in regulating metaphase plate (middle). transcription, mRNA - Centrosomes have moved to the processing, and differentiation opposite ends of the cell. - Sister chromatids are attached to of nerve cells. the kinetochore (where spindle ➔ Cyclins, when attached to fibers attach in the centromere). CDKs, are now called MPFs Anaphase - Shortest stage of mitosis. (Maturation-Promoting Factor) - Sister chromatids separate. which regulate the cell cycle. - Newly formed daughter chromosomes move towards the opposite ends of the cell - By its end, both ends now have 1 Towards the end of S phase, cyclin identical and complete sets of accumulates and starts to form. (individual) chromosomes. 2 In G2, cyclin combines with CDK to produce Telophase - Two daughter nuclei form. MPF. With enough MPF, the cell passes the - Nuclear membrane is created. G2 checkpoint and begins mitosis. - Nucleoli reappear. - Chromosomes decondense. 3 MPF phosphorylates proteins, promoting - Remaining spindle microtubules 7  are depolymerized. ➔ Happens in and only in sex cells or - Marks the completion of mitosis gametes where a single cell divides where one nucleus divides into into four unique daughter cells. two genetically identical nuclei. - Is basically the reverse of ➔ Daughter cells in meiosis only have Prophase. half the number of chromosomes as Cytokinesis - “Cell motion.” the parent cell, hence why they are - Second main stage of the mitotic haploid cells. phase where the cytoplasm is physically separated into two Ploidy Number of sets of chromosomes in daughter cells. cells. - Animal cells undergo cytokinesis through the formation of a Haploid (n) One copy of each chromosome; cleavage furrow that grows from gametes/sex cells. the outside and cuts the cell in half. Diploid (2n) Two sets of chromosomes; - Plant cells undergo cytokinesis by somatic/body cells; organisms forming a cell plate inside the cell receive one type of chromosome and divides the compartment into from female parents and one from two. male parent, hence why body cells have two sets. Table 2.4. Stages of mitosis Figure 2.5. Stages of mitosis Figure 2.6. Diploid vs haploid cells Table 2.5. Ploidy levels ➔ Humans’ body cells have 46 chromosomes, 2 pairs of 23 Figure 2.4. Cytokinesis chromosomes. 22 of these pairs are autosomes (also exist in C. Uncontrolled Mitosis - Cancer homologous pairs: homologues) cells while the 23rd pair is the sex ➔ Due to genetic mutations, DNA gets chromosomes. damaged and protein functions are ➔ Humans’ gametes (sperm/ova) have altered which may cause cancer 22 autosomes and 1 sex cells to defy normal cell cycle chromosome. regulations, dividing even without ➔ Does not have a duplication of growth factors. chromosomes. ➔ Cancer cells may divide indefinitely and evade apoptosis, transforming 1. Meiosis I into tumors. ➔ During DNA duplication in the S 1. Malignant tumor - breaks phase, each chromosome is away; can form more tumors. replicated, producing two 2. Benign tumors - remain identical copies called sister clustered and can be removed. chromatids. ➔ Oncogenes are special proteins ➔ Centrosomes also replicate, that increase chances of a normal preparing the cell to enter cell developing into a tumor cell. prophase I. ➔ In cancer cells, cell checkpoints are disabled. Prophase I - Centrosome movement, spindle formation, and nuclear envelope D. Meiosis fragments. - Chromosomes condense. - Homologous chromosomes bind to form a tetrad (contains four 8  chromatids). Cytokinesis - Two daughter cells from meiosis I - The tetrads form an x-shaped divides, producing four unique region called chiasmata which is haploid cells. the site for crossing over, the - Newly formed nuclei are both process where genetic material is haploid. exchanged between homologous Table 2.7. Stages of meiosis II chromosomes. This forms recombinant chromosomes. Figure 2.7. Crossing over Metaphase - Homologous chromosomes align I at the metaphase plate, one chromosome of each pair facing each pole. Anaphase I - Spindle microtubules pull the Figure 2.8. Meiosis I and II homologous chromosomes apart. side by side comparison. - Cohesion at centromere persists, hence why sister chromatids move together. Meiosis I Meiosis II Telophase I - Both daughter cells now have a Synapsis occurs No synapsis complete haploid set of duplicated chromosomes. Crossing over occurs No crossing over Cytokinesis - Cytoplasm divides producing two In Metaphase I, paired In Metaphase II, sister haploid daughter cells. homologous chromatids line up - Chromosomes decondense and chromosomes line up nuclear envelope reassembles. In Anaphase I, paired In Anaphase II, sister Table 2.6. Stages of meiosis I homologous chromatids separate chromosomes 2. Meiosis II separate ➔ The sister chromatids in each of Produces 2 haploid Produces 4 haploid the daughter cells formed in cells cells Meiosis I separate to form four Table 2.8. Meiosis I and II comparison new haploid gametes. ➔ Similar to mitosis except that 3. Mitosis vs Meiosis each dividing cell has only one set of chromosomes. Mitosis Meiosis Has 1 division Has 2 divisions Prophase II - Sister chromatids condense. - Spindle forms. Produces 2 daughter Produces 4 daughter - Nuclear envelope disintegrates. cells cells Prometaph - Nuclear envelope disappears. Genetically identical Unique ase II - Spindle fibers attach on the kinetochores on sister chromatids. Diploid Haploid Metaphase - Sister chromatids or recombinant Happens in somatic Happens in sex II chromosomes are maximally (body) cells (reproductive) cells condensed and align at the equator. Happens throughout Happens at sexual life maturity Anaphase II - Sister chromatids are pulled apart and move towards opposite poles. For growth and repair For sexual reproduction Telophase II - Chromosomes arrive at the Table 2.9. Mitosis and Meiosis comparison opposite poles and begin to decondense. - Nuclear envelope forms. 4. Nondisjunction 9  ➔ Happens when a pair of - A portion has turned homologous chromosomes fail upside down. to separate at anaphase so both - Ex. Increases the risk chromosomes pass to one of miscarriage daughter cell. 4. Translocation ➔ Often in meiosis but can occur in - Portions of two mitosis as well. different ➔ Causes of nondisjunction are chromosomes unknown, however, it could be interchanged. associated with increasing - Ex. Chronic maternal age and inheritance. myelogenous 1. Mitotic Nondisjunction - leukemia occurs in anaphase when 5. Insertion sister chromatids fail to - A portion of one separate. chromosome is 2. Meiotic Nondisjunction - inserted/transferred has two types: during into another. meiosis I when homologous - ex. cystic fibrosis chromosomes do not separate at anaphase I II. Numerical Chromosome which causes all haploid Abnormalities cells having an abnormal 1. Monosomy (2n-1) number of chromosomes, - The absence of one and during meiosis II when member of a pair of sister chromatids fail to chromosomes. segregate, causing half the - Ex. In humans, haploid cells with abnormal instead of having 46 chromosomes. chromosomes, there are only a total of 45 (such as Turner Syndrome). 2. Trisomy (2n+1) - The presence of 3 chromosomes rather than the usual pair with only two Figure 2.9. Normal chromosome vs nondisjunction chromosomes. - Ex. Trisomy 21(also 2 Types of Chromosomal Aberrations known as Down syndrome) where the I. Structural Chromosome 21st pair has three Abnormalities chromosomes 1. Deletion instead of just 2. - A portion is 3. Tetrasomy (2n+2) lost/removed. - Four total copies of a - Ex. Angelman chromosome are syndrome present. 2. Duplication - Ex. Tetrasomy 9p - A portion is doubled/duplicated. - Ex. Fragile X syndrome 3. Inversion 10 Practice Test a. A Gram-Positive bacteria’s cell wall is made up of chitin. Try answering the following tests as review b. A Gram-Positive bacteria’s for the Midterm Exams. The answer key of cell wall, when dyed, the questions is located on the 13th page absorbs the violet stain and of the reviewer. Good luck! turns pink. c. A Gram-Positive bacteria’s I. Multiple Choice. cell wall is composed of 1. How does a prokaryotic cell differ more layers of peptidoglycan from a eukaryotic cell? compared to a a. A prokaryotic cell has a cell Gram-Negative bacteria’s wall whereas eukaryotic cells wall. do not. d. A Gram-Positive bacteria has b. A prokaryotic cell contains a thinner cell wall. membrane-bound organelles 5. This is the only apical modification like ribosomes while that does not have microtubules eukaryotic cells don’t. arranged in a 9+2 arrangement. c. A prokaryotic cell does not a. Microvilli have DNA and ribosomes in b. Stereocilia their nucleoids while a c. Cilia eukaryotic cell does. d. Flagella d. A prokaryotic cell does not 6. What do you call the kind of cell have a true nucleus and division that happens in sex cells membrane-bound organelles where the daughter cells are unique while a eukaryotic cell does. from their parent cells? 2. What differentiates the Rough ER a. Mitosis and the Smooth ER from each b. Meiosis other? c. Cytokinesis a. The Rough ER destroys toxic d. Cell Cycle substances and delivers 7. How many parts is the Interphase them to the Smooth ER for divided into? recycling. a. 1 b. The Rough ER contains b. 2 ribosomes while the Smooth c. 3 ER contains genetic material. d. 4 c. The Rough ER has 8. What does a Maturation-Promoting ribosomes which participate Factor contribute to the cell cycle? in the synthesis of proteins a. It attaches to CDK and while the Smooth ER makes marks the start of Mitosis. lipids. b. It gives a “Stop” signal to the d. There is no difference cycle when it detects errors between the Rough and in the replication of DNA. Smooth ER. c. It regulates transcription, 3. What cell part is present in plant precesses mRNA, and cells but not in animal cells? differentiates nerve cells a. Vacuole from body cells. b. Cell Wall d. It phosphorylates proteins c. Lysosome and promotes the start of d. Cell Membrane Mitosis. 4. How does the cell wall composition 9. In this stage, homologous of a Gram-Positive bacteria different chromosomes line up along the from that of a Gram-Negative metaphase plate in preparation for bacteria? separation. a. Prophase I 11  b. Prophase II c. Metaphase I d. Metaphase II 10. When a portion of a chromosome is detached, turned upside-down, and reattaches to the chromosome, it undergoes an abnormality called ________. a. Inversion b. Insertion c. Duplication d. Translocation II. Identification. 11. What are the two faces of the Golgi Apparatus? 12. What is the inner membrane of a mitochondrion called? 13. This type of lateral modification provides mechanical strength to tissues, helping cells resist shearing forces. 14. During this stage of the cell cycle, DNA is replicated? 15. When undergoing cytokinesis, what forms inside a plant cell that divides its compartments into two? 16. This kind of tumor remains only clustered and can still be removed. 17. This is the region crossing over happens in Prophase I of Meiosis. 18. This is a type of numerical chromosome abnormality where there are two additional copies of a chromosome is present instead of only two? 19. Who first saw the center of a cell? 20. What do you call the organelle for digestion, storage, waste disposal, water balance, cell growth, and protection? 12  Answer Key I. Multiple Choice. 1. D 2. C 3. B 4. C 5. B 6. B 7. C 8. D 9. C 10. A II. Multiple Choice. 11. Cis and Trans 12. Cristae 13. Desmosomes 14. Interphase (s-phase) 15. Cell Plate 16. Benign Tumor 17. Chiasmata 18. Tetrasomy 19. Robert Brown 20. Vacuole _______________________________________ Prepared by: Jhullia Francheska Ebol Abraham Kalim Anya Shine Macaso 13