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[GENERAL BIOLOGY] MIDTERM | SEM 1 | GRADE 12 | STEM In 1665, Hooke published GENERAL BIOLOGY "Micrographia," a seminal work in which he...

[GENERAL BIOLOGY] MIDTERM | SEM 1 | GRADE 12 | STEM In 1665, Hooke published GENERAL BIOLOGY "Micrographia," a seminal work in which he described his observations Microscope using a microscope, including his famous examination of cork cells. an optical instrument used to view objects that are too small to be seen by Anton van Leeuwenhoek (1632-1723) the naked eye. S magnifies small objects by using a A few years later, he created a system of lenses and illumination to microscope with a much higher R make them appear larger and more magnification than the microscope that detailed. Hooke used. Leeuwenhoek used his microscope to observe specimens such ZE The Invention of Microscope as bacteria, blood cells, and protists. He created a portable microscope Hans & Zacharias Janssen Father of Microbiology His detailed observations led to the LA Around 1595, the first compound microscope was invented by Zacharias Janssen (1580-1638). It is believed that Zacharias probably discovery of single-celled organisms, which he referred to as “animalcules.” Types of Microscopes LB had help from his father, Hans, because he was still young at that time. Light Microscopes: Use visible light and lenses They made these microscopes by to magnify objects. Common types include: placing several lenses together, and AI discovered that objects were further Compound Microscopes: Typically used enlarged upon viewing. in biology to observe cells and Hans and Zacharias Janssen were microorganisms. TR credited with the invention of the first Stereo Microscopes: Provide a compound microscope. three-dimensional view, often used for dissecting and observing larger samples. Galileo Galilei Electron Microscopes: Use beams of electrons E He added a focusing mechanism called instead of light to achieve much higher “Occhiolino” or “Little Eye” magnifications and resolutions. Types include: TH Robert Hooke (1580-1638) Transmission Electron Microscopes (TEM): For viewing thin sections of In 1665, he examined a thin slice of cork samples at high magnification. under the microscope that he built. Scanning Electron Microscopes (SEM): He was able to see and observe small For detailed three-dimensional views of compartments of the cork. He initially the surface of specimens. named the small compartments “cellula” because they reminded him of the little Parts of the Microscope rooms in the monastery. These eventually became known as A compound microscope is a powerful optical cells. instrument that uses multiple lenses to magnify [GENERAL BIOLOGY] MIDTERM | SEM 1 | GRADE 12 | STEM small objects. The main parts of a compound microscope are as follows: Base: The bottom part of the microscope Eyepiece (Ocular Lens): The lens at the that supports the instrument. top that you look through. They are usually 10x or 15x power. Light Source (Illuminator): A steady S light source used in place of a mirror. It Scanning Objective Lens (4x): This lens shines light up through the slide. R provides the lowest magnification, typically 4x. It is used to get an overview of the specimen and to locate ZE specific areas for closer examination. Diaphragm (Iris or Disc Diaphragm): Located under the stage, it controls the amount of light that reaches the specimen. LA Low Power Objective Lens (10x): With a 10x magnification, this lens is used for a closer view of the specimen while still providing a wide field of view. Condenser: A lens system located below LB the stage that focuses light onto the specimen. High Power Objective Lens (40x): This AI lens provides higher magnification, usually 40x, and is used to view finer Fine Adjustment Knob: A smaller, details of the specimen. fine-tuning knob that moves the stage TR slightly to sharpen the focus of the specimen. Stage: The flat platform where the slide is placed. E Stage Clips: Clips on the stage that hold Coarse Adjustment Knob: A larger knob the slide in place. that moves the stage up and down to bring the specimen into general focus. TH Nosepiece (Turret): The rotating part that holds the objective lenses. It allows Body Tube (Head): The part of the you to switch between different lenses. microscope that connects the eyepiece to the objective lenses The Basic Principles of Microscopy Arm: The part of the microscope that connects the base to the head and The basic principles of microscopy revolve eyepiece tube. It is used to carry the around magnifying and resolving the fine details microscope. [GENERAL BIOLOGY] MIDTERM | SEM 1 | GRADE 12 | STEM of small objects that are too tiny to be seen with Definition: The field of view is the area the naked eye. of the specimen visible through the microscope. 1. Magnification Inversely Related to Magnification: As magnification increases, the field of Definition: Magnification is the process view decreases. of enlarging the appearance of an object. 1. Depth of Field How It Works: Microscopes use a Definition: The depth of field is the S combination of lenses to increase the thickness of the specimen that is in size of an image. The total focus at any given time. R magnification is the product of the Relation to Magnification: Higher magnifications of the objective lens and magnification decreases the depth of the eyepiece. field. ZE 2. Resolution Definition: Resolution is the ability to SUMMARY entities. LA distinguish two points as separate Importance: High resolution allows for clearer and more detailed images. It's Microscopy is a fundamental technique used in various scientific fields to view and analyze objects that are too small to be seen with the LB dependent on the wavelength of light naked eye. By employing microscopes, which used and the numerical aperture of the utilize different types of lenses and light sources, lenses. researchers can magnify and investigate the structure and details of specimens at AI 3. Contrast microscopic levels. Definition: Contrast is the difference in KEYWORDS TO REMEMBER TR light intensity between the specimen and the background. Microscope Enhancement Techniques: Staining, phase contrast, and differential - Used to see things that are small to be interference contrast (DIC) are seen by the naked eye. E commonly used to improve contrast and make the specimen details more visible. Hand and Zacharias TH 4. Illumination - Credited with the invention of the first compound microscope Role: Proper lighting is essential to view the specimen clearly. Galileo Galilei Types: Common illumination techniques include brightfield (light passes through - Added a focusing mechanism the specimen) and darkfield (light is “occhiolino” scattered by the specimen). Antonie Van Leewenhoek 5. Field of View - Father of microbiology [GENERAL BIOLOGY] MIDTERM | SEM 1 | GRADE 12 | STEM - discovery of single-celled organisms, - Depending on the location. which he referred to as “animalcules.” Cytoplasm Robert Hooke Enclosed within the cell membrane is - Coined the term “Cell” the cytoplasm. It contains the semifluid - published "Micrographia," a seminal substance called the cytosol where the work in which he described his different organelles are suspended. S observations using a microscope R Cell Structure and Function Within the Cytosol: Cells - Electrolytes - Substances that ZE produce electrically conducting Cells are involved in all processes that solutions. sustain life. Whatever is needed by the - Metabolites - Substances microscopic cells in your body produced during metabolism. LA determines what you need as a macroscopic organism. Everything that you ingest is absorbed by the cells, and everything that is eliminated by the cells - RNA and Synthesized proteins - Physiological processes The cytoplasm has several important roles. This is where the molecules first LB M will be excreted by your body. pass through after entering or before exiting the cell membrane. The All the processes that occur within an organism organelles can also move within and are supported by the cell. The cell contains around the cytoplasm. AI different parts, called organelles, which carry out The cytoplasm appears to have no form. different functions. However, it does have a structure due to the presence of the cytoskeleton. It has TR Cell Membrane three major filaments: the microfilament, the microtubule, and the The cell is bound by the cell membrane. intermediate filament. The cell membrane is composed of phospholipid bilayer embedded with Centrioles E proteins and carbohydrates. It is semipermeable, which means that not During cell division, the microtubules TH everything can enter or pass through it. eventually arrange themselves in a Semi-permeable specific manner to form centrioles. - Allows cells to choose the These centrioles come in pairs and are at substances to absorb, secrete or right angles with each other. excrete. They help in the separation and transfer Membrane Proteins of the replicated genetic materials in the - Participate in the transport cells called chromosomes. molecules You can observe chromosomes as the Microvilli threadlike structures that you see in a - Specialized fingerlike folds. To dividing cell. increase the surface area of the cell. Nucleus Microvilli Function [GENERAL BIOLOGY] MIDTERM | SEM 1 | GRADE 12 | STEM The nucleus (plural: nuclei) serves as The ribosomal subunits combine to the control center of the cell, because it become the ribosome. is where most of the genetic processes take place. Ribosomes Inside the nuclear envelope is the nucleoplasm. Within the nucleoplasm Ribosomes are small, dense structures are strands of chromatin, which is a that help in the assembly of proteins in combination of deoxyribonucleic acid the cell. S (DNA) and proteins. Ribosomes come in different forms. Chromatin strands further condense to Ribosomes may be found freely in the R form chromosomes during cell division. cytoplasm, attached to the endoplasmic Substances that move in and out of the reticulum, or as a polyribosome, a series nucleus pass through the envelope's of ribosomes attached to mRNA ZE nuclear pores. The information in the chromatin Endoplasmic Reticulum strands enables the nucleus to control the activities of the cell. The endoplasmic reticulum (plural: LA The DNA in the chromatin strands is the basis for the duplication of new genetic materials. This duplication ensures that new cells endoplasmic reticula) is a membrane-bound organelle that forms a network of interconnected sacs called cisterna (plural: cisternae). LB formed during cell division will have In between its membranes is the lumen, genetic materials of their own. or the cisternal space. The DNA is the basis of the information The rough ER produces proteins. In the taken by the messenger ribonucleic acid pancreas and the digestive tract, proteins AI (MRNA) for protein synthesis. This in the form of enzymes break down ensures that ribosomes will get the food. Without these enzymes, digestion information about specific proteins that is almost impossible In most cases, these TR need to be produced. proteins move to the Golgi apparatus for modification, packaging, and Nucleolus distribution. The smooth ER, on the other hand, The nucleolus (plural: nucleoli) is a produces lipids Phospholipids and E membrane-free organelle found inside cholesterol of the cell membrane can the nucleus. It is usually spherical in come from the lipids produced by the TH shape. It contains fibrils and granules. smooth endoplasmic reticulum. The fibrils have DNA coding for Phospholipids make up the bilipid layer ribosomal RNA (rRNA). The granules of the cell membrane, whereas the contain rRNA molecules with proteins cholesterol regulates the cell coming from the cytoplasm. membrane's fluidity. Without these The nucleolus is important in creating substances, the cell membrane will the ribosomes, which are the sites of cease to exist. This also detoxifies the protein synthesis. cell of certain substances. The rRNA produced by the nucleolus, This capability becomes useful when a together with the protein exported from person drinks too much alcohol or when the cytoplasm, produce the ribosomal one overdoses on a drug. subunit. [GENERAL BIOLOGY] MIDTERM | SEM 1 | GRADE 12 | STEM Golgi Bodies/Apparatus The lysosomal membrane contains a special carbohydrate covering its inner Just like the endoplasmic reticulum, surface. membrane-bound Golgi bodies also This prevents the lysosome from consist of cisternae. There are two faces releasing the hydrolytic enzymes all at in the Golgi bodies. The part facing the once. If this happens, the cell may be endoplasmic reticulum is called the cis killed. This is why the lysosome is also face, whereas the one facing the called the "suicide bag" of the cell S cytoplasm or the cell membrane is nucleus. called the trans face. R Golgi bodies work closely with the Mitochondria endoplasmic reticulum. The substance produced in the endoplasmic reticulum The mitochondrion is responsible for ZE (e.g., protein) enters its lumen, which is producing adenosine triphosphate the space inside the organelle. The (ATP), the energy currency of the cell. substance then pinches off to become a Powerhouse of the Cell vesicle. LA The vesicle moves toward the cis face. The Golgi bodies may modify the substances in the vesicle by putting "tags” so that the substances will be Cells that can only be seen in Plant Cell (3 C’s) Cell Wall LB recognized and accepted in their In plant cells, there is an additional cell respective destinations. Once ready, the covering called the cell wall. vesicles containing the modified The cell wall distinguishes plant cells substances exit at the trans face. from animal cells. AI The cell wall is located outside the cell Lysosomes membrane and is primarily made of cellulose. TR The lysosome is a membrane-bound Cellulose is a polysaccharide, which is a organelle that originated from the substance composed of a long chain of endoplasmic reticulum. It has hydrolytic carbohydrates. enzymes (proteins that use water to The cell wall maintains the shape of the break down substances) that serve plant, protects the cell, and helps E several functions: digest food, recycle regulate the cell's uptake of water. old components of the cell, and kill TH invading microorganisms. Chloroplast The digested food and recycled components are released into the cytosol Plants can make their own food through to be used by the cell. The indigestible a process called photosynthesis, a series food stays in the lysosomes, which of chemical reactions using sunlight to eventually become the residual bodies. convert carbon dioxide and water to Residual bodies can be eliminated by glucose. Glucose can either be stored as exocytosis. starch or be used in respiration later on. There may be several hundred Oxygen is the by-product of lysosomes in a single animal cell. photosynthesis. Plants and other organisms are able to perform [GENERAL BIOLOGY] MIDTERM | SEM 1 | GRADE 12 | STEM photosynthesis because of chloroplasts daughter cells only have half the number in their cells. of chromosomes of the parent cell – they The chloroplast, like the mitochondrion, are haploid. is a double-membrane organelle. Inside the chloroplast is the stroma (plural: Cell Types and Cell Modifications stromata), a colorless fluid surrounding several grana (singular: granum). Prokaryotic cells S Vacuole or Central Vacuole - are single-celled organisms that do not contain membrane-bound organelles or a R Animals and plants have vacuoles, but nucleus; both of which are present in the vacuoles of the latter are usually eukaryotic cells. Prokaryotes are the larger and are thus observed more easily earliest known lifeforms on earth, ZE when viewed under the microscope. including bacteria and archaebacteria. In most mature plant cells, the vacuole that occupies the largest space is called Eukaryotic cells the central vacuole. LA The central vacuole is surrounded by a membrane called the tonoplast. In animals, the vacuole serves as the temporary storage of substances. In - - are organisms whose cells contain a nucleus and other membrane-bound organelles. There is a wide range of eukaryotic LB plants, the central vacuole's main organisms, including all animals, plants, function is to maintain turgor pressure to fungi, and protists, as well as most keep the cell from wilting. algae. Turgor pressure is the pressure exerted - Eukaryotes may be either single-celled AI onto the cell wall by water moving into or multicellular. the cell. The central vacuole contains a higher. Cell Specialization TR Mitosis Also known as cell differentiation. Process by which generic cells change the process by which a cell replicates its to different types of cells to be able to chromosomes and then segregates them, perform special or specific functions. E producing two identical nuclei in preparation for cell division. Specialized Cell TH is generally followed by equal division of the cell's content into two daughter Cells designed to carry out a certain cells that have identical genomes. role. Cells which have specific components Meiosis and a specific structure. a process where a single cell divides Egg Cell twice to produce four cells containing half the original amount of genetic The female sex cell. information. They are made in the ovaries and During meiosis one cell divides twice to released during the menstrual cycle. form four daughter cells. These four An egg cell joins with a sperm cell during fertilization to make an embryo. [GENERAL BIOLOGY] MIDTERM | SEM 1 | GRADE 12 | STEM The nucleus of the egg cell contains Nerve cells are thin and very long, so genetic material they can carry messages over long The cytoplasm contains nutrients for the distances in the body. embryo to grow They have branched connections allowing them to pass messages all over Sperm Cell the body. They are surrounded by a fatty myelin The male sex cell. sheath which increases the speed that S They are made in the testes after messages can travel. puberty. R A sperm cell joins with the egg cell Muscle Cell during fertilization to form an embryo. The tail supports movement towards the Muscle cells are cells which are found in ZE egg. bundles which make up muscles Sperm cells contain lots of mitochondria throughout the body. to release energy for movement. Muscle cells are able to contract and The nucleus contains genetic relax information. Red Blood Cell LA They can be found in many locations e.g. cardiac muscle in the heart, skeletal muscles which are joined to bones and smooth muscles such as the cells which LB Red blood cells are cells found in the line the stomach. blood. They contain haemoglobin which carries Fat Cell oxygen around the body. AI The disc shape increases surface area, so Fat cells store energy in the form of fat. more oxygen can be absorbed in the Fat cells can expand to store more fat. lungs. They have few mitochondria as fat cells TR There is no nucleus, which allows more need very little energy. space to carry oxygen. Fat acts as soft elastic padding to protect organs. White Blood Cell Ciliated Cell E White blood cells are part of the immune system. Cells which are found in the airways to TH They help the body fight infection and move mucus and dust out disease. They are also found in the oviducts to White blood cells have an irregular move the egg cell from the ovaries to shape so they can squeeze out of blood the uterus vessels and get to the site of infection. Ciliated cells have tiny hairs on top of Some can change shape to surround and them called cilia which beat in a rhythm engulf pathogens. Specialized Cells in Plant Cells Nerve Cell Cell modification Nerve cells transmit electrical signals in the nervous system. Hair-like organelles extending from the cell surface [GENERAL BIOLOGY] MIDTERM | SEM 1 | GRADE 12 | STEM Types of cilia It ensures that each daughter cell Non-motile or primary cilia (sensory) receives an exact copy of the parent Motile (movement) cell's DNA, playing a vital role in: 1. growth Flagella 2. development 3. tissue repair Long, whip-like, tail-like structure made https://youtu.be/f-ldPgEfAHI?si=VvO7 of protein filaments D0ONKRcDPsGI S aids in movement Meiosis R Villi or Microvilli a specialized type of cell division that Small, slender, vascular, finger-like produces four genetically diverse ZE projections gametes, each with half the number of Increases surface area to increase chromosomes of the parent cell. absorption in the intestine This process is essential for sexual reproduction and contributes to genetic Cell Cycle Apoptosis LA variation in offspring. https://youtu.be/f-ldPgEfAHI?si=VvO7 D0ONKRcDPsGI LB programmed cell death Cell cycle regulation Somatic cell a complex system of checks and balances that ensures cells divide AI any cell in an organism's body apart accurately and at the appropriate time. from the gametes This regulatory mechanism is crucial for maintaining the health of an organism, TR Gametes as it prevents uncontrolled cell growth and division, which can lead to cancer sex cells and other disorders. Interphase To further understand the cell cycle, watch this E video from the Amoeba sisters: Phase of the cell cycle in which a typical cell spends most of its life. TH https://youtu.be/QVCjdNxJreE?si=fIa1rbeR4BE Interphase is the "daily living" or CZj15 metabolic phase of the cell, in which the cell obtains nutrients and metabolizes Cancer them, grows, replicates its DNA in preparation for mitosis, and conducts a disease characterized by uncontrolled other "normal" cell functions. cell growth and division, often resulting from failures in the mechanisms that Mitosis regulate the cell cycle. a crucial process of cell division that results in two genetically identical daughter cells from a single parent cell. Prepared By: Mercado, Richard Ashlee M. [GENERAL BIOLOGY] MIDTERM | SEM 1 | GRADE 12 | STEM Following Lessons Discussed By: Sir Aguilar, Melvin P. Link of the Sources: PPTS: https://nationalueduph.sharepoint.com/:b:/s/ S T1_12STEM2408_SSGBIO1_CARBONELL/ EfUiyouaJCdNiB6XLTeMUBYBwZtHSd0PH R pgDNivYq3tuKA https://nationalueduph.sharepoint.com/:p:/s/ T1_12STEM2408_SSGBIO1_CARBONELL/ ZE EZP1PO2-2JRLpHeDyJHdtVUBmKc7Z7pF UAqY__gdotQpFQ https://nationalueduph.sharepoint.com/:b:/s/ T1_12STEM2408_SSGBIO1_CARBONELL/ oLIqiIPK00OUA Amoeba Sisters: LA ETYIpbJjWRFLm-NCQ1ecHJQBGL2gvijb2 LB https://youtu.be/8IlzKri08kk?si=vQxSb-MeD yxCmUT4 AI https://youtu.be/6mgkoqcm6Sg?si=iHQpvBM ggSQa6vCz TR https://youtu.be/QVCjdNxJreE?si=HwG1QiS Fz8nfaZ7P https://youtu.be/f-ldPgEfAHI?si=ClOaEKIsI E bByNOcO TH https://youtu.be/VzDMG7ke69g?si=EkCSjD HKcz_Epdmp