PRELIMS

• What are the main steps in preparing a plant cell slide for observation?

  1. Place a drop of water on a slide.
  2. Remove a thin layer of onion epidermis.
  3. Spread the epidermis on the water drop.
  4. Add methylene blue stain and cover with a slip.
  5. Focus under low, medium, and high power.
• What should be included in the drawing of the onion cell observation?

  Total magnification, cell wall, cell membrane, nucleus, cytoplasm, and chloroplast with labels.
• What is the morphology of the onion cell as described in the study material?

  The onion cell has a grid-like pattern with visible cell walls outlining each cell.
• How does the visibility of the nucleus change with different magnifications when observing onion cells?

  The nucleus becomes clearer and more defined as the magnification increases.
• What are the main components of an onion cell?

  • Cell Wall: Rigid outer layer for structure and protection.
  • Cell Membrane: Controls substance movement.
  • Nucleus: Contains genetic material (DNA).
  • Cytoplasm: Gel-like substance for cellular processes.
  • Vacuole: Stores nutrients and maintains rigidity.
• What are the main steps in preparing an animal cell slide for observation?

  1. Place a drop of water on a slide.
  2. Rub a toothpick on the inner cheek and swish it in the water.
  3. Add iodine solution.
  4. Focus under low, medium, and high power.
  5. Draw and label the cheek cells.
• What is the shape of cheek cells as observed under a microscope?

  Cheek cells are scattered and irregularly shaped.
• What is the significance of the absence of a cell wall in animal cells?

  It allows animal cells to be more flexible compared to plant cells.
• Compare the visible organelles in plant and animal cells as described in the study material.

  • Plant Cells: Nucleus, cell wall, large central vacuole.
  • Animal Cells: Nucleus, cell membrane, cytoplasm.
• What are the key differences between onion and cheek cells?

  • Presence of Cell Wall: Only in onion cells.
  • Vacuoles: Large central vacuole in onion cells, absent in cheek cells.
  • Shape: Onion cells are rectangular; cheek cells are round.
  • Chloroplasts: Present in green plants, absent in cheek cells.
• What role does the cell membrane play in animal cells?

  It protects the cell and regulates what enters and exits.
• What is the main function of the nucleus in both plant and animal cells?

  It controls cellular activities and contains DNA.
• What are the properties of water that make it important for living systems?

  • Natural solvent for minerals and substances.
  • Dispersion medium for colloidal cells.
  • Medium for most biological reactions.
  • Constitutes about 70% of the human body.
• What is solubility?

  Solubility is the ability of a substance (solute) to dissolve in a solvent, forming a homogeneous solution.
• Why is solubility important in chemistry?

  It is crucial for understanding how substances interact in different environments.
• How does water's polarity affect its ability to dissolve substances?

  Water's polarity allows it to interact with and dissolve ionic and polar compounds.
• What are the characteristics of polar and nonpolar solvents?

  • Polar Solvents: Dissolve ionic and polar substances; have charge separation (e.g., water).
  • Nonpolar Solvents: Dissolve nonpolar substances; lack charge separation (e.g., CCl4).
• What is an acid-base reaction?

  It is a chemical reaction between an acid and a base, often producing salt, water, and sometimes gas.
• What is the significance of the solubility experiment described in the study material?

  • Illustrates how polarity affects dissolution.
  • Demonstrates the effectiveness of water as a solvent.
  • Highlights the "like dissolves like" principle.
• What happens when citric acid and sodium bicarbonate are mixed with water?

  Immediate bubbling occurs, indicating the release of carbon dioxide gas.
• What are the key takeaways from the experiments on solubility and acid-base reactions?

  • Solubility is affected by polarity.
  • Acid-base reactions produce gas and demonstrate chemical reactivity.
  • Knowledge is applicable in various industries.
• What are carbohydrates and their significance?

  • Include polyhydroxy aldehydes or ketones.
  • Major source of energy in the diet.
  • Important for metabolic processes and carbon chain synthesis.
• What are the three categories of carbohydrates?

  Monosaccharides, disaccharides, and polysaccharides.
• What are monosaccharides and their solubility characteristics?

  Monosaccharides are highly soluble in water, less soluble in ethanol, and insoluble in ether.
• How are monosaccharides classified based on their functional groups?

  They can be classified as aldoses or ketoses.
• What is mutarotation in monosaccharides?

  Mutarotation is the ability of monosaccharides to exist as α and β forms.
• What are disaccharides and how are they formed?

  • Formed by two molecules of monosaccharides.
  • Examples include sucrose and lactose.
• What are polysaccharides and their characteristics?

  • Composed of long chains of monosaccharides.
  • Serve as energy storage (e.g., starch, glycogen) or structural components (e.g., cellulose).
• What are carbohydrates composed of?

  Carbohydrates are composed of carbon, hydrogen, and oxygen.
• Why are carbohydrates important in our diet?

  They serve as the major source of energy and are essential for metabolic processes.
• What are the basic categories of carbohydrates?

  • Monosaccharides
  • Disaccharides
  • Polysaccharides
• What distinguishes monosaccharides from disaccharides?

  Monosaccharides are single sugar units, while disaccharides are formed by two monosaccharides.
• What are examples of monosaccharides?

  Examples of monosaccharides include glucose, fructose, and galactose.
• How can monosaccharides be classified based on their structure?

  They can be classified as aldoses or ketoses depending on the functional group present.
• What is mutarotation in the context of monosaccharides?

  Mutarotation refers to the ability of monosaccharides to exist in alpha and beta forms.
• What are disaccharides formed from?

  Disaccharides are formed by the combination of two monosaccharides.
• What is an example of a disaccharide?

  Examples of disaccharides include maltose, sucrose, and lactose.
• What is the primary function of polysaccharides in nature?

  Polysaccharides primarily function as structural units or energy storage molecules.
• What are some examples of polysaccharides?

  Examples of polysaccharides include cellulose, starch, glycogen, and inulin.
• What is the significance of the glycosidic bond?

  The glycosidic bond links monosaccharide units in disaccharides and polysaccharides.