Science 7 Unit 7: Introduction to Cells PDF

‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭ esson 1‬ L ‭ ellular Structure and Observation‬ C ‭Table of Contents‬ ‭Introduction‬...

‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭ esson 1‬ L ‭ ellular Structure and Observation‬ C ‭Table of Contents‬ ‭Introduction‬ ‭1‬ ‭Learning Competency‬ ‭2‬ ‭Learning Targets‬ ‭2‬ ‭Knowledge Kickstarter‬ ‭2‬ ‭Warm-Up‬ ‭4‬ ‭Learn about It‬ ‭8‬ ‭Types of Cells‬ ‭10‬ ‭Cellular Structures and Functions‬ ‭11‬ ‭Key Points‬ ‭14‬ ‭Check Your Understanding‬ ‭15‬ ‭Self Assessment‬ ‭16‬ ‭Reflection‬ ‭16‬ ‭References‬ ‭17‬ ‭Answer Key‬ ‭18‬ ‭0‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭1‬ ‭Cellular Structure and Observation‬ ‭Figure 1. An onion peel stained and viewed under the microscope‬ ‭Introduction‬ ‭Have‬‭you‬‭ever‬‭wondered‬‭what‬‭you‬‭are‬‭made‬‭of?‬‭Cells‬‭are‬‭the‬‭tiny‬‭building‬‭blocks‬‭of‬ ‭all‬‭living‬‭things.‬‭They‬‭are‬‭so‬‭small‬‭that‬‭you‬‭need‬‭a‬‭microscope‬‭to‬‭see‬‭them!‬‭Imagine‬ ‭a‬‭bustling‬‭city,‬‭with‬‭different‬‭parts‬‭working‬‭together—that‬‭is‬‭like‬‭a‬‭cell!‬‭From‬‭the‬‭tiny‬ ‭bacteria to the leaves on trees, cells are everywhere and crucial to life.‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭1‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭Learning Competency‬ ‭At‬‭the‬‭end‬‭of‬‭this‬‭lesson,‬‭the‬‭learners‬‭should‬‭be‬‭able‬‭to‬‭use‬‭proper‬‭techniques‬‭in‬‭observing‬ ‭and‬ ‭identifying‬ ‭the‬ ‭parts‬ ‭of‬ ‭a‬ ‭cell‬ ‭with‬ ‭a‬ ‭microscope,‬ ‭such‬ ‭as‬ ‭the‬ ‭cell‬ ‭membrane,‬‭nucleus,‬ ‭cytoplasm, mitochondria, chloroplasts, and ribosomes.‬ ‭Learning Targets‬ ‭In this lesson, you should be able to do the following:‬ ‭‬ ‭Observe and identify key parts of a cell.‬ ‭‬ ‭Utilize a microscope for detailed observation.‬ ‭Knowledge Kickstarter‬ ‭Choose the best answer for each question. Write the letter of the correct answer‬ ‭before the number.‬ ‭_______1.‬ ‭Who first discovered the existence of cells in 1665?‬ ‭A. Isaac Newton‬ ‭B. Antonie van Leeuwenhoek‬ ‭C. Robert Hooke‬ ‭D. Marie Curie‬ ‭_______2.‬ ‭Which of the following statements is a fundamental principle of cell‬ ‭theory?‬ ‭A. Cells are the basic units of life.‬ ‭B. Cells can only be seen with a microscope.‬ ‭C. Only animal cells are important.‬ ‭D. Cells do not divide.‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭2‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭_______3.‬ ‭Where is DNA primarily located in a cell?‬ ‭A. cell wall‬ ‭B. Golgi apparatus‬ ‭C. nucleus‬ ‭D. cytoplasm‬ ‭_______4.‬ ‭What would happen if the cell membrane was damaged?‬ ‭A. increased energy production‬ ‭B. decreased cell growth‬ ‭C. improved DNA replication‬ ‭D. uncontrolled substance entry and exit‬ ‭_______5.‬ ‭What would the mitochondria represent if you compared a cell to a city?‬ ‭A. city hall‬ ‭B. power plant‬ ‭C. public library‬ ‭D. roads‬ ‭_______6.‬ ‭In a real-life scenario, how does being knowledgeable about cells help‬ ‭doctors?‬ ‭A. designing buildings‬ ‭B. creating medicines‬ ‭C. teaching history‬ ‭D. programming computers‬ ‭_______7.‬ ‭What role does the nucleus play in a cell?‬ ‭A. It generates energy.‬ ‭B. It stores genetic information.‬ ‭C. It produces proteins.‬ ‭D. It digests food.‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭3‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭_______8.‬ ‭Evaluate the role of organelles. Which is‬‭not‬‭found‬‭in prokaryotic cells?‬ ‭A. DNA‬ ‭B. mitochondria‬ ‭C. ribosomes‬ ‭D. cytoplasm‬ ‭_______9.‬ ‭Which process would be most affected in analyzing cell functions if the‬ ‭Golgi apparatus was removed?‬ ‭A. energy production‬ ‭B. nutrient transport‬ ‭C. protein modification‬ ‭D. waste removal‬ ‭_______10.‬ ‭When evaluating cell sizes, why are smaller cells more efficient?‬ ‭A. They have more DNA.‬ ‭B. They reproduce faster.‬ ‭C. They have a higher surface area-to-volume ratio.‬ ‭D. They consume less energy.‬ ‭Warm-Up‬ ‭Tiny Cell Experiment‬ ‭Materials‬ ‭‬ ‭gelatin powder‬ ‭‬ ‭a ruler‬ ‭‬ ‭food coloring‬ ‭‬ ‭a sharp knife‬ ‭‬ ‭salt‬ ‭‬ ‭measuring spoon‬ ‭‬ ‭a shallow baking dish or‬ ‭tray‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭4‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭Procedure‬ ‭1.‬ ‭Prepare‬ ‭the‬ ‭gelatin‬ ‭in‬ ‭the‬ ‭shallow‬ ‭dish‬ ‭according‬ ‭to‬ ‭package‬ ‭instructions,‬ ‭adding a few drops of food coloring.‬ ‭2.‬ ‭Once‬ ‭set,‬ ‭use‬ ‭the‬ ‭ruler‬ ‭and‬ ‭knife‬ ‭to‬ ‭cut‬ ‭the‬ ‭gelatin‬ ‭into‬ ‭cubes‬ ‭of‬ ‭different‬ ‭sizes (e.g., 1 cm, 2 cm, and 3 cm on each side).‬ ‭3.‬ ‭Place the cubes on a flat surface.‬ ‭4.‬ ‭Sprinkle the same amount of salt on each cube.‬ ‭5.‬ ‭Start‬ ‭a‬ ‭timer‬ ‭and‬ ‭observe‬ ‭the‬ ‭changes‬‭over‬‭time‬‭(e.g.,‬‭at‬‭5-minute‬‭intervals‬ ‭for up to 30 minutes).‬ ‭6.‬ ‭Record‬‭how‬‭the‬‭salt‬‭affects‬‭each‬‭cube‬‭size,‬‭focusing‬‭on‬‭the‬‭rate‬‭of‬‭shrinkage‬ ‭or any other changes.‬ ‭7.‬ ‭Here‬ ‭is‬ ‭how‬ ‭to‬ ‭compute‬ ‭the‬ ‭gelatin‬ ‭cubes’‬ ‭surface‬ ‭area,‬ ‭volume,‬ ‭and‬ ‭their‬ ‭ratio:‬ ‭a.‬ ‭Surface‬‭area:‬‭To‬‭calculate‬‭the‬‭surface‬‭area‬‭of‬‭a‬‭cube,‬‭use‬‭the‬‭formula:‬ ‭surface‬ ‭area‬ ‭=‬ ‭6‬ ‭×‬ ‭(side‬ ‭length)².‬ ‭This‬ ‭means‬ ‭you‬ ‭first‬ ‭multiply‬ ‭the‬ ‭length‬ ‭of‬ ‭one‬ ‭side‬ ‭of‬ ‭the‬ ‭cube‬ ‭by‬ ‭itself.‬ ‭Then,‬ ‭multiply‬‭this‬‭by‬‭6.‬‭For‬ ‭example,‬‭if‬‭a‬‭cube’s‬‭side‬‭is‬‭6‬‭cm‬‭long,‬‭its‬‭surface‬‭area‬‭is‬‭6‬‭×‬‭(6‬‭cm)²‬‭=‬ ‭216 cm².‬ ‭b.‬ ‭Volume:‬‭To‬‭calculate‬‭the‬‭volume‬‭of‬‭a‬‭cube,‬‭use‬‭the‬‭formula:‬‭volume‬‭=‬ ‭(side‬ ‭length)³.‬ ‭This‬ ‭means‬ ‭you‬ ‭multiply‬ ‭the‬ ‭length‬ ‭of‬ ‭one‬ ‭side‬‭of‬‭the‬ ‭cube‬‭by‬‭itself‬‭three‬‭times.‬‭For‬‭example,‬‭if‬‭a‬‭cube’s‬‭side‬‭is‬‭6‬‭cm‬‭long,‬‭its‬ ‭volume is (6 cm)³ = 216 cm³.‬ ‭c.‬ ‭Ratio:‬ ‭To‬ ‭find‬ ‭the‬ ‭surface‬ ‭area‬ ‭to‬ ‭volume‬ ‭ratio,‬ ‭simply‬ ‭divide‬ ‭the‬ ‭surface‬ ‭area‬ ‭by‬ ‭the‬ ‭volume.‬ ‭For‬ ‭instance,‬ ‭if‬ ‭the‬ ‭surface‬ ‭area‬ ‭is‬ ‭216‬ ‭cm² and the volume is 216 cm³, the ratio is 216 cm² / 216 cm³ = 1:1.‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭5‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭Observation Table‬ ‭Table 1.‬‭Cell size simulation: surface area to volume‬‭ratio in gelatin cubes‬ ‭1 cm cube‬ ‭2 cm cube‬ ‭3 cm cube‬ ‭Surface Area (cm²)‬ ‭Volume (cm³)‬ ‭Surface Area to‬ ‭Volume Ratio‬ ‭Initial Observation‬ ‭Observation‬ ‭after 5 min‬ ‭Observation‬ ‭after 10 min‬ ‭Observation‬ ‭after 15 min‬ ‭Guide Questions‬ ‭1.‬ ‭Which‬ ‭gelatin‬ ‭cubes‬ ‭showed‬ ‭a‬ ‭more‬ ‭noticeable‬ ‭reaction‬ ‭to‬ ‭the‬ ‭salt?‬ ‭Consider‬ ‭the‬ ‭surface area to volume ratio in your answer.‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭6‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭2.‬ ‭How‬‭does‬‭this‬‭experiment‬‭help‬‭us‬‭understand‬‭the‬‭importance‬‭of‬‭cell‬‭size‬‭in‬‭relation‬ ‭to their function in living organisms?‬ ‭3.‬ ‭If‬‭cells‬‭were‬‭larger,‬‭how‬‭might‬‭their‬‭ability‬‭to‬‭absorb‬‭nutrients‬‭and‬‭remove‬‭waste‬‭be‬ ‭affected? Relate this to your observations of the gelatin cubes of different sizes.‬ ‭Essential‬ ‭ uestion‬ Q ‭How‬ ‭does‬ ‭the‬ ‭surface‬ ‭area‬ ‭to‬ ‭volume‬ ‭ratio‬ ‭of‬ ‭a‬ ‭cell‬ ‭influence‬ ‭its‬ ‭efficiency‬ ‭in‬ ‭performing‬ ‭vital‬ ‭functions,‬ ‭and‬ ‭what‬ ‭might‬ ‭be‬ ‭the‬ ‭implications‬ ‭for‬ ‭larger‬ ‭or‬ ‭smaller organisms?‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭7‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭Learn about It‬ ‭Cells,‬ ‭the‬ ‭basic‬ ‭units‬ ‭of‬‭life,‬‭were‬‭first‬‭observed‬‭by‬‭Robert‬‭Hooke‬‭in‬‭1665.‬‭He‬‭used‬‭a‬ ‭compound‬ ‭microscope‬ ‭to‬ ‭look‬ ‭at‬ ‭thin‬ ‭slices‬‭of‬‭cork,‬‭a‬‭dried‬‭part‬‭of‬‭some‬‭plants.‬‭He‬ ‭saw‬ ‭tiny‬ ‭rectangular‬ ‭spaces‬ ‭in‬ ‭the‬ ‭cork.‬ ‭Not‬ ‭only‬ ‭that,‬ ‭but‬ ‭he‬ ‭compared‬ ‭these‬ ‭to‬ ‭a‬ ‭monk’s‬‭cellular‬‭room‬‭and‬‭called‬‭these‬‭structures,‬‭cells.‬‭This‬‭groundbreaking‬‭discovery‬ ‭led‬ ‭to‬ ‭the‬ ‭development‬ ‭of‬ ‭cell‬ ‭theory‬‭,‬ ‭which‬ ‭is‬ ‭central‬ ‭to‬ ‭our‬ ‭understanding‬ ‭of‬ ‭biology. Cell theory includes three important points:‬ ‭‬ ‭All living things are made up of cells.‬ ‭‬ ‭Cells are the smallest units of life.‬ ‭‬ ‭New cells come from pre-existing cells through cell division.‬ ‭This‬‭theory‬‭highlights‬‭the‬‭importance‬‭of‬‭cells‬‭in‬‭all‬‭organisms'‬‭structure,‬‭function,‬‭and‬ ‭reproduction.‬ ‭Figure 2. Development of cell theory‬ ‭Do‬ ‭you‬ ‭know‬ ‭why‬ ‭cells‬ ‭are‬ ‭small?‬ ‭Let‬ ‭us‬ ‭consider‬ ‭how‬ ‭a‬ ‭scent‬‭spreads‬‭in‬‭rooms‬‭of‬ ‭different‬ ‭sizes.‬ ‭Imagine‬ ‭you‬ ‭light‬ ‭a‬ ‭scented‬ ‭candle‬ ‭in‬ ‭a‬ ‭small‬ ‭room.‬ ‭You‬ ‭will‬ ‭notice‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭8‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭that‬ ‭the‬ ‭scent‬ ‭fills‬ ‭the‬ ‭space‬ ‭quickly,‬ ‭enveloping‬ ‭the‬‭room‬‭in‬‭a‬‭pleasant‬‭aroma.‬‭This‬ ‭happens‬‭because,‬‭in‬‭a‬‭smaller‬‭space,‬‭scent‬‭particles‬‭have‬‭less‬‭area‬‭to‬‭travel,‬‭allowing‬ ‭them to diffuse rapidly.‬ ‭Conversely,‬ ‭if‬ ‭you‬ ‭light‬ ‭the‬ ‭same‬ ‭candle‬ ‭in‬ ‭a‬ ‭much‬ ‭larger‬ ‭room,‬ ‭the‬ ‭scent‬ ‭will‬ ‭take‬ ‭significantly‬‭longer‬‭to‬‭be‬‭noticeable‬‭across‬‭the‬‭entire‬‭area.‬‭This‬‭is‬‭due‬‭to‬‭the‬‭larger‬‭air‬ ‭volume‬ ‭that‬ ‭the‬ ‭scent‬ ‭particles‬ ‭must‬ ‭move‬ ‭through,‬ ‭making‬ ‭the‬ ‭diffusion‬ ‭process‬ ‭slower.‬ ‭This‬‭principle‬‭of‬‭diffusion‬‭in‬‭different‬‭spaces‬‭directly‬‭ties‬‭into‬‭why‬‭cells‬‭are‬‭small‬‭and‬ ‭why‬ ‭surface‬ ‭area‬ ‭to‬ ‭volume‬ ‭ratio‬ ‭is‬ ‭important.‬ ‭As‬ ‭demonstrated‬ ‭in‬ ‭our‬ ‭"Tiny‬ ‭Cell‬ ‭Experiment,"‬ ‭smaller‬ ‭gelatin‬ ‭cubes,‬ ‭representing‬ ‭cells,‬ ‭reacted‬ ‭more‬ ‭quickly‬ ‭to‬ ‭salt‬ ‭due‬‭to‬‭their‬‭larger‬‭surface‬‭area‬‭relative‬‭to‬‭their‬‭volume.‬‭This‬‭experiment‬‭highlights‬‭a‬ ‭crucial‬‭biological‬‭concept:‬‭small‬‭cells‬‭have‬‭a‬‭higher‬‭surface‬‭area‬‭to‬‭volume‬‭ratio.‬‭This‬ ‭makes‬ ‭them‬ ‭more‬ ‭efficient‬ ‭in‬ ‭transporting‬ ‭nutrients‬ ‭and‬ ‭waste‬‭materials.‬‭Similar‬‭to‬ ‭how‬ ‭the‬ ‭scent‬ ‭diffuses‬ ‭more‬ ‭quickly‬ ‭in‬ ‭a‬ ‭small‬ ‭room,‬ ‭small‬ ‭cells‬ ‭can‬ ‭exchange‬ ‭substances‬ ‭more‬ ‭rapidly‬ ‭and‬ ‭efficiently.‬ ‭This‬ ‭illustrates‬ ‭the‬ ‭practical‬ ‭implications‬ ‭of‬ ‭cell size on their function.‬ ‭Figure 3. Smaller objects have high surface area to volume ratio‬ ‭as compared to larger objects.‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭9‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭Types of Cells‬ ‭Prokaryotic‬ ‭and‬ ‭eukaryotic‬ ‭cells‬ ‭are‬ ‭the‬ ‭two‬ ‭primary‬ ‭types‬ ‭of‬ ‭cells‬ ‭that‬ ‭make‬ ‭up‬ ‭all‬ ‭living‬ ‭organisms.‬ ‭The‬ ‭key‬ ‭difference‬ ‭between‬ ‭them‬ ‭lies‬ ‭in‬ ‭their‬‭structural‬‭complexity‬ ‭and organization.‬ ‭The‬ ‭term‬ ‭prokaryotic‬ ‭is‬ ‭derived‬ ‭from‬ ‭Greek,‬ ‭where‬ ‭pro‬ ‭means‬ ‭"before"‬ ‭and‬ ‭karyon‬ ‭means‬ ‭"nut"‬ ‭or‬ ‭"kernel,"‬ ‭referring‬ ‭to‬ ‭the‬ ‭nucleus.‬ ‭Prokaryotic‬ ‭cells‬‭,‬ ‭therefore,‬ ‭are‬ ‭cells‬‭that‬‭lack‬‭a‬‭true‬‭nucleus.‬‭These‬‭cells‬‭are‬‭generally‬‭smaller‬‭and‬‭simpler‬‭in‬‭structure.‬ ‭They‬ ‭are‬ ‭commonly‬ ‭found‬ ‭in‬ ‭bacteria‬ ‭and‬ ‭archaea.‬ ‭Their‬ ‭genetic‬ ‭material‬ ‭is‬ ‭not‬ ‭enclosed‬‭within‬‭a‬‭membrane-bound‬‭nucleus;‬‭instead,‬‭it‬‭is‬‭typically‬‭in‬‭a‬‭single,‬‭circular‬ ‭strand of DNA located in an area of the cell called the‬‭nucleoid‬‭.‬ ‭In‬‭contrast,‬‭eukaryotic,‬‭also‬‭originating‬‭from‬‭Greek,‬‭where‬‭eu‬‭means‬‭"true,"‬‭and‬‭karyon‬ ‭again‬‭refers‬‭to‬‭the‬‭nucleus.‬‭It‬‭describes‬‭cells‬‭with‬‭a‬‭true‬‭nucleus‬‭enclosed‬‭by‬‭a‬‭nuclear‬ ‭membrane.‬ ‭Eukaryotic‬ ‭cells‬ ‭are‬ ‭more‬ ‭complex‬ ‭and‬ ‭are‬ ‭typically‬ ‭larger‬ ‭than‬ ‭prokaryotic‬ ‭cells.‬ ‭They‬ ‭comprise‬ ‭various‬ ‭organisms,‬ ‭including‬ ‭animals,‬ ‭plants,‬ ‭fungi,‬ ‭and‬ ‭protists.‬ ‭Besides‬ ‭the‬ ‭distinct‬ ‭nucleus,‬ ‭eukaryotic‬ ‭cells‬ ‭also‬ ‭have‬ ‭other‬ ‭membrane-bound‬‭organelles‬‭like‬‭mitochondria‬‭and‬‭chloroplasts‬‭(in‬‭plants),‬‭which‬‭are‬ ‭absent‬ ‭in‬ ‭prokaryotes.‬ ‭This‬ ‭advanced‬ ‭compartmentalization‬ ‭allows‬ ‭for‬ ‭more‬ ‭specialized functions within the cell.‬ ‭Figure 4. Difference between prokaryotic and eukaryotic cells‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭10‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭Cellular Structures and Functions‬ ‭Figure 5. Parts of animal (top) and plant (bottom) cell‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭11‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭Table‬ ‭2‬ ‭offers‬ ‭a‬ ‭comprehensive‬ ‭overview‬ ‭of‬ ‭cellular‬ ‭components,‬ ‭called‬ ‭organelles,‬ ‭and‬ ‭their‬ ‭distinct‬ ‭functions‬ ‭within‬ ‭the‬ ‭cell.‬ ‭This‬ ‭table‬ ‭categorizes‬ ‭these‬ ‭organelles‬ ‭based on their location (exterior, interior, and endomembrane systems).‬ ‭The‬ ‭exterior‬ ‭group‬ ‭includes‬ ‭structures‬ ‭like‬ ‭the‬ ‭cell‬ ‭membrane‬ ‭and‬ ‭cell‬ ‭wall,‬ ‭which‬ ‭interact‬ ‭with‬ ‭the‬ ‭cell's‬ ‭external‬ ‭environment,‬ ‭protection,‬‭and‬‭movement.‬‭The‬‭interior‬ ‭group,‬ ‭encompassing‬ ‭the‬ ‭cytoplasm,‬ ‭nucleus,‬ ‭ribosomes,‬ ‭centrioles,‬ ‭mitochondria,‬ ‭and‬ ‭chloroplasts,‬ ‭includes‬ ‭components‬ ‭that‬ ‭manage‬ ‭cellular‬ ‭processes‬ ‭like‬ ‭energy‬ ‭production,‬ ‭genetic‬ ‭material‬ ‭storage,‬ ‭and‬ ‭protein‬ ‭synthesis.‬ ‭Lastly,‬ ‭the‬ ‭endomembrane‬‭system,‬‭comprising‬‭the‬‭endoplasmic‬‭reticulum,‬‭Golgi‬‭apparatus/body,‬ ‭lysosomes,‬ ‭and‬ ‭vacuoles,‬ ‭is‬ ‭involved‬ ‭in‬ ‭the‬ ‭synthesis,‬ ‭modification,‬ ‭and‬ ‭transport‬ ‭of‬ ‭cellular materials and waste processing.‬ ‭This‬ ‭categorization‬ ‭provides‬ ‭an‬ ‭organized‬ ‭framework‬ ‭to‬ ‭understand‬ ‭how‬ ‭each‬ ‭part‬ ‭contributes‬ ‭to‬ ‭the‬ ‭cell's‬ ‭overall‬ ‭function.‬ ‭It‬ ‭illustrates‬ ‭the‬ ‭remarkable‬‭complexity‬‭and‬ ‭coordination‬‭within‬‭even‬‭the‬‭smallest‬‭unit‬‭of‬‭life.‬‭The‬‭table‬‭also‬‭describes‬‭each‬‭and‬‭its‬ ‭function‬ ‭and‬ ‭presence‬ ‭in‬ ‭different‬ ‭cell‬ ‭types‬ ‭(prokaryotic,‬ ‭eukaryotic,‬‭and‬‭specifically‬ ‭within‬ ‭plant‬ ‭or‬ ‭animal‬ ‭cells).‬ ‭This‬ ‭tabular‬ ‭presentation‬ ‭is‬ ‭an‬ ‭invaluable‬ ‭resource‬ ‭for‬ ‭understanding‬ ‭the‬ ‭complexity‬ ‭and‬ ‭diversity‬ ‭of‬ ‭cellular‬ ‭functions‬ ‭and‬ ‭how‬ ‭these‬ ‭components work in harmony to maintain the cell's life processes.‬ ‭Table 2.‬‭Parts of the cell‬ ‭Present in‬ ‭Specific to‬ ‭Organelle/‬ ‭Description‬ ‭Function‬ ‭Prokaryotic/‬ ‭Plant/‬ ‭Structure‬ ‭Eukaryotic‬ ‭Animal/ Both‬ ‭controls entry and‬ ‭protective outer‬ ‭exit of nutrients‬ ‭cell membrane‬ ‭both‬ ‭both‬ ‭layer‬ ‭and minerals in‬ ‭the cell‬ ‭eukaryotic (plant),‬ ‭provides support‬ ‭cell wall‬ ‭rigid outer layer‬ ‭prokaryotic‬ ‭plant‬ ‭and protection‬ ‭(some)‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭12‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭Present in‬ ‭Specific to‬ ‭Organelle/‬ ‭Description‬ ‭Function‬ ‭Prokaryotic/‬ ‭Plant/‬ ‭Structure‬ ‭Eukaryotic‬ ‭Animal/ Both‬ ‭gel-like‬ ‭site for chemical‬ ‭cytoplasm‬ ‭substance inside‬ ‭both‬ ‭both‬ ‭reactions‬ ‭the cell‬ ‭contains the‬ ‭controls cell‬ ‭nucleus‬ ‭cell's genetic‬ ‭eukaryotic‬ ‭both‬ ‭activities‬ ‭material (DNA)‬ ‭site of protein‬ ‭synthesizes‬ ‭ribosomes‬ ‭both‬ ‭both‬ ‭synthesis‬ ‭proteins‬ ‭eukaryotic‬ ‭cylindrical‬ ‭involved in cell‬ ‭centrioles‬ ‭(mostly animal‬ ‭animal‬ ‭structures‬ ‭division‬ ‭cells)‬ ‭powerhouse of‬ ‭produces energy‬ ‭mitochondria‬ ‭eukaryotic‬ ‭both‬ ‭the cell‬ ‭(ATP)‬ ‭endoplasmic‬ ‭network of‬ ‭synthesizes‬ ‭eukaryotic‬ ‭both‬ ‭reticulum‬ ‭membranes‬ ‭proteins and lipids‬ ‭stacks of‬ ‭modifies, sorts,‬ ‭Golgi apparatus/‬ ‭flattened‬ ‭and packages‬ ‭eukaryotic‬ ‭both‬ ‭body‬ ‭membranes‬ ‭proteins‬ ‭contain‬ ‭break down waste‬ ‭lysosomes‬ ‭digestive‬ ‭eukaryotic‬ ‭mostly animal‬ ‭and cell debris‬ ‭enzymes‬ ‭contain‬ ‭convert solar‬ ‭chloroplasts‬ ‭chlorophyll for‬ ‭energy to‬ ‭eukaryotic‬ ‭plant‬ ‭photosynthesis‬ ‭chemical energy‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭13‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭Present in‬ ‭Specific to‬ ‭Organelle/‬ ‭Description‬ ‭Function‬ ‭Prokaryotic/‬ ‭Plant/‬ ‭Structure‬ ‭Eukaryotic‬ ‭Animal/ Both‬ ‭storage, waste‬ ‭both (large‬ ‭large fluid-filled‬ ‭vacuole‬ ‭disposal, growth,‬ ‭central vacuole in‬ ‭both‬ ‭sac‬ ‭and protection‬ ‭plants)‬ ‭Did You Know?‬ ‭The‬ ‭largest‬ ‭cell‬ ‭in‬ ‭the‬ ‭world‬ ‭is‬ ‭the‬ ‭ostrich‬ ‭egg,‬ ‭while‬ ‭the‬ ‭smallest is the‬‭Mycoplasma genitalium‬‭, a type of bacteria.‬ ‭Key Points‬ ‭‬ ‭Cells‬‭are the basic units of life, discovered by Robert‬‭Hooke in 1665.‬ ‭‬ ‭Cell theory‬‭states that all living things are made‬‭of cells, cells are the smallest units‬ ‭of life, and new cells come from existing cells.‬ ‭‬ ‭Cells have a‬‭high surface area-to-volume ratio‬‭, making‬‭them efficient in‬ ‭transporting nutrients and waste.‬ ‭‬ ‭There are two main types of cells:‬‭prokaryotic‬‭(like‬‭bacteria, without a nucleus) and‬ ‭eukaryotic‬‭(like plant and animal cells, with a nucleus).‬ ‭‬ ‭Cells have different parts, called‬‭organelles‬‭, each‬‭with its own function.‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭14‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭Check Your Understanding‬ ‭Match‬ ‭the‬ ‭terms‬ ‭on‬ ‭the‬ ‭left‬ ‭with‬ ‭their‬ ‭correct‬ ‭description‬ ‭on‬ ‭the‬ ‭right.‬ ‭Draw‬ ‭a‬ ‭line‬ ‭connecting each term to its description.‬ ‭Column A‬ ‭Column B‬ ‭_______1.‬ ‭Robert Hooke‬ ‭A.‬ ‭the largest cell in the world‬ ‭_______2.‬ ‭cell theory‬ ‭B.‬ ‭discovered cells in 1665‬ ‭_______3.‬ ‭prokaryotic cells‬ ‭C.‬ ‭controls‬ ‭entry‬ ‭and‬ ‭exit‬‭of‬‭substances‬‭in‬ ‭_______4.‬ ‭eukaryotic cells‬ ‭cells‬ ‭_______5.‬ ‭cell membrane‬ ‭D.‬ ‭the‬ ‭powerhouse‬ ‭of‬ ‭the‬ ‭cell,‬ ‭producing‬ ‭_______6.‬ ‭mitochondria‬ ‭energy‬ ‭_______7.‬ ‭nucleus‬ ‭E.‬ ‭stores‬ ‭and‬ ‭protects‬ ‭the‬ ‭cell's‬ ‭genetic‬ ‭_______8.‬ ‭cytoplasm‬ ‭material‬ ‭_______9.‬ ‭endoplasmic‬ ‭F.‬ ‭jelly-like‬ ‭substance‬ ‭that‬ ‭holds‬ ‭cell‬ ‭parts‬ ‭reticulum‬ ‭in place‬ ‭_______10.‬ ‭Golgi apparatus‬ ‭G.‬ ‭involved in protein and lipid synthesis‬ ‭_______11.‬ ‭surface area to‬ ‭H.‬ ‭modifies and transports proteins‬ ‭volume ratio‬ ‭I.‬ ‭explains‬ ‭the‬ ‭importance‬ ‭of‬ ‭cells‬ ‭being‬ ‭_______12.‬ ‭DNA‬ ‭small‬ ‭_______13.‬ ‭ostrich egg‬ ‭J.‬ ‭genetic material found in cells‬ ‭_______14.‬ ‭chloroplast‬ ‭K.‬ ‭cells without a nucleus‬ ‭_______15.‬ ‭cell size efficiency‬ ‭L.‬ ‭cells with a nucleus and organelles‬ ‭M.‬ ‭involved in photosynthesis‬ ‭N.‬ ‭describes‬ ‭that‬ ‭all‬‭living‬‭things‬‭are‬‭made‬ ‭of cells‬ ‭O.‬ ‭demonstrates‬ ‭how‬ ‭cell‬ ‭size‬ ‭affects‬ ‭function‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭15‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭Self Assessment‬ I‭ think I need‬ I‭ have a minimal‬ I‭ am confident‬ ‭Skills‬ ‭more time and‬ ‭understanding of‬ ‭that I can do this‬ ‭assistance.‬ ‭it.‬ ‭with ease.‬ ‭I can observe and‬ ‭identify key parts of‬ ‭a cell.‬ ‭I can utilize a‬ ‭microscope for‬ ‭detailed‬ ‭observation.‬ ‭Reflection‬ ‭I find‬‭______________________‬‭the most interesting‬‭because‬‭________________________________‬‭.‬ ‭I need to improve on‬‭________________________‬‭because‬‭___________________________________‬‭.‬ ‭I need to practice‬‭_________________________‬‭because‬‭______________________________________‬‭.‬ ‭I plan to‬‭___________________________________________________________________________________.‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭16‬ ‭Science 7‬ ‭Unit 7: Introduction to Cells‬ ‭References‬ ‭Alberts, Bruce, Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts, and Peter Walter. 2015.‬ ‭Molecular Biology of the Cell‬‭. 6th ed. New York: Garland‬‭Science.‬ ‭Campbell, Neil A., and Jane B. Reece. 2015.‬‭Biology‬‭.‬‭10th ed. Boston: Pearson.‬ ‭Lodish, Harvey, Arnold Berk, Chris A. Kaiser, Monty Krieger, Anthony Bretscher, Hidde Ploegh,‬ ‭Angelika‬ ‭Amon,‬ ‭and‬ ‭Matthew‬‭P.‬‭Scott.‬‭2016.‬‭Molecular‬‭Cell‬‭Biology‬‭.‬‭8th‬‭ed.‬‭New‬‭York:‬‭W.‬‭H.‬ ‭Freeman.‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭17‬  ‭Science 7‬ ‭7.1. Cellular Structure and Observation‬ ‭Answer Key‬ ‭Knowledge Kickstarter‬ ‭1.‬ ‭C. Robert Hooke‬ ‭6.‬ ‭B. creating medicines‬ ‭2.‬ ‭A. Cells are the basic units of life.‬ ‭7.‬ ‭B. It stores genetic information.‬ ‭3.‬ ‭C. nucleus‬ ‭8.‬ ‭B. mitochondria‬ ‭4.‬ ‭D. uncontrolled substance entry‬ ‭9.‬ ‭C. protein modification‬ ‭and exit‬ ‭10.‬ ‭C. They have a higher surface‬ ‭5.‬ ‭B. power plant‬ ‭area-to-volume ratio‬ ‭Warm-Up‬ ‭1.‬ ‭Which‬ ‭gelatin‬ ‭cubes‬ ‭showed‬ ‭a‬ ‭more‬ ‭noticeable‬ ‭reaction‬ ‭to‬ ‭the‬ ‭salt?‬ ‭Consider‬ ‭the‬ ‭surface area to volume ratio in your answer.‬ ‭The‬‭smaller‬‭gelatin‬‭cubes‬‭showed‬‭a‬‭more‬‭noticeable‬‭reaction‬‭to‬‭the‬‭salt‬‭because‬ ‭they‬‭have‬‭a‬‭higher‬‭surface‬‭area-to-volume‬‭ratio.‬‭This‬‭means‬‭a‬‭larger‬‭proportion‬‭of‬ ‭the‬ ‭cube's‬ ‭volume‬ ‭is‬ ‭exposed‬ ‭to‬ ‭salt,‬ ‭leading‬ ‭to‬ ‭more‬ ‭efficient‬ ‭water‬ ‭loss‬ ‭and‬ ‭shrinkage.‬ ‭In‬ ‭larger‬ ‭cubes,‬ ‭less‬ ‭surface‬ ‭area‬ ‭is‬ ‭exposed‬ ‭relative‬ ‭to‬‭their‬‭volume,‬ ‭slowing down the process.‬ ‭2.‬ ‭How‬‭does‬‭this‬‭experiment‬‭help‬‭us‬‭understand‬‭the‬‭importance‬‭of‬‭cell‬‭size‬‭in‬‭relation‬ ‭to their function in living organisms?‬ ‭This‬‭experiment‬‭illustrates‬‭the‬‭importance‬‭of‬‭cell‬‭size‬‭in‬‭relation‬‭to‬‭their‬‭function.‬ ‭Cells‬ ‭are‬ ‭small‬ ‭to‬ ‭maximize‬ ‭their‬ ‭surface‬ ‭area‬ ‭relative‬ ‭to‬ ‭their‬ ‭volume,‬ ‭allowing‬ ‭efficient‬ ‭exchange‬ ‭of‬ ‭materials‬ ‭like‬ ‭nutrients‬ ‭and‬ ‭waste.‬ ‭If‬ ‭the‬ ‭cells‬ ‭were‬ ‭larger,‬ ‭this‬ ‭exchange‬ ‭would‬ ‭be‬ ‭less‬ ‭efficient,‬ ‭similar‬ ‭to‬ ‭how‬ ‭the‬ ‭larger‬ ‭gelatin‬ ‭cubes‬ ‭showed less reaction to the salt.‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭18‬  ‭Science 7‬ ‭7.1. Cellular Structure and Observation‬ ‭3.‬ ‭If‬‭cells‬‭were‬‭larger,‬‭how‬‭might‬‭their‬‭ability‬‭to‬‭absorb‬‭nutrients‬‭and‬‭remove‬‭waste‬‭be‬ ‭affected? Relate this to your observations of the gelatin cubes of different sizes.‬ ‭If‬ ‭cells‬ ‭were‬ ‭larger,‬ ‭their‬ ‭ability‬ ‭to‬ ‭absorb‬ ‭nutrients‬‭and‬‭remove‬‭waste‬‭would‬‭be‬ ‭less‬ ‭efficient.‬ ‭This‬ ‭is‬ ‭because‬ ‭larger‬ ‭cells‬ ‭would‬ ‭have‬ ‭a‬ ‭smaller‬ ‭surface‬ ‭area‬ ‭relative‬ ‭to‬ ‭their‬ ‭volume,‬ ‭making‬ ‭the‬ ‭exchange‬ ‭of‬ ‭materials‬ ‭slower‬ ‭and‬ ‭less‬ ‭effective.‬‭In‬‭the‬‭experiment,‬‭the‬‭larger‬‭gelatin‬‭cubes‬‭shrunk‬‭less‬‭than‬‭the‬‭smaller‬ ‭ones, demonstrating how size affects the rate of material exchange.‬ ‭Check Your Understanding‬ ‭1.‬ ‭B‬ ‭2.‬ ‭N‬ ‭3.‬ ‭K‬ ‭4.‬ ‭L‬ ‭5.‬ ‭C‬ ‭6.‬ ‭D‬ ‭7.‬ ‭E‬ ‭8.‬ ‭F‬ ‭9.‬ ‭G‬ ‭10.‬ ‭H‬ ‭11.‬ ‭I‬ ‭12.‬ ‭J‬ ‭13.‬ ‭A‬ ‭14.‬ ‭M‬ ‭15.‬ ‭O‬ ‭7.1.‬‭Cellular Structure and Observation‬ ‭19‬