🧪•Biology•🧪

• What are specialized cells?


  Specialized cells are cells that have developed specific features to perform particular functions within an organism.
• During interphase, DNA replicates so there is one copy per chromosome. The nucleolus produces ribosomes, which will later attach themselves to the rough endoplasmic reticulum (RER). Ribosomes synthesise proteins using mRNA as a template. Protein molecules are then transported by vesicles to other parts of the cell where they are needed.
• Metaphase - Spindle fibres pull chromosomes towards centre of cell. Each pair of sister chromatids align along equatorial plate. Kinetochore microtubules attached to centrosomes at opposite poles of cell.
• Prophase - Chromatin condenses into visible chromosomes. Centrioles move apart from each other and spindle fibres form between them. Nuclear envelope breaks down and nuclear pores disappear. Cytokinesis begins with formation of cleavage furrow around edge of cytoplasm.
• The mitotic phase consists of prophase, metaphase, anaphase and telophase
• Animal cells do not contain chloroplasts or mitochondria
• What is diffusion?

  Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration.
• What are the functions of the following organelles: nucleus, cytoplasm, mitochondria, ribosome, chloroplast, vacuole, and cell wall?

  • Nucleus: Contains genetic material and controls cell activities.
  • Cytoplasm: Site of metabolic processes and contains organelles.
  • Mitochondria: Produces energy through respiration.
  • Ribosome: Synthesizes proteins.
  • Chloroplast: Conducts photosynthesis in plant cells.
  • Vacuole: Stores substances and maintains turgor pressure in plant cells.
  • Cell wall: Provides structure and support to plant cells.
• What are specialised cells?

  Specialised cells are cells that have specific structures and functions to perform particular tasks.
• How is magnification calculated?

  Magnification is calculated by dividing the size of the image by the size of the real object.
• Give an example of diffusion occurring in nature.

  Oxygen diffusing from the lungs into the bloodstream.
• What is osmosis?

  Osmosis is the movement of water molecules through a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
• What is the function of the cell membrane?

  The cell membrane controls the movement of substances in and out of the cell.
• What is the function of mitochondria?

  Mitochondria produce energy through the process of respiration.
• What is the function of ribosomes?

  Ribosomes synthesize proteins.
• What is the function of chloroplasts?

  Chloroplasts conduct photosynthesis in plant cells.
• What is the function of vacuoles?

  Vacuoles store substances and maintain turgor pressure in plant cells.
• What is the function of the cell wall?

  The cell wall provides structure and support to plant cells.
• What is active transport?

  Active transport is the movement of substances across a cell membrane against their concentration gradient, requiring energy.
• Give an example of active transport occurring in nature.

  Glucose being absorbed into the bloodstream from the intestines.
• If a cell is 0.075 mm wide and the image is 7.5 mm wide, what is the magnification?

  Magnification = $\frac{7.5 \text{ mm}}{0.075 \text{ mm}} =$$100$
• What is the difference between adult and embryonic stem cells?

  Adult stem cells are multipotent and can differentiate into a limited range of cell types, while embryonic stem cells are pluripotent and can differentiate into any cell type.
• Give an example of when adult stem cells are used in nature.

  Adult stem cells are used in the healing of tissues, such as in bone marrow for blood cell production.
• What is the difference between prokaryotic and eukaryotic cells?

  Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have a nucleus and membrane-bound organelles.
• Give an example of a prokaryotic cell.

  Bacteria are an example of prokaryotic cells.
• Give an example of a eukaryotic cell.

  Animal cells and plant cells are examples of eukaryotic cells.
• What is mitosis?

  Mitosis is the process of cell division that results in two identical daughter cells.
• Why do we need mitosis? Give two reasons.

  We need mitosis for growth and repair of tissues.
• What is cell differentiation?

  Cell differentiation is the process by which a cell becomes specialized for a specific function.
• How is differentiation different in plant and animal cells?

  In plant cells, differentiation can occur throughout the life of the plant, while in animal cells, it typically occurs during development.
• Cytokinesis occurs during both mitosis and meiosis
• What is the definition of magnification?

  Magnification is a measure of how much larger an image appears compared to the actual size of the object.
• What is the formula for calculating magnification?

  Magnification = Image size / Actual size
• How can the magnification formula be used?


  The formula allows us to calculate any of the three variables if we know the other two.
• What does magnification represent in simpler terms?

  Magnification is like a zoom factor that tells us how many times bigger something looks compared to its real size.
• If something looks 100 times bigger than it really is, what is its magnification?

  The magnification is 100 times.
• What does "Image size" represent in the magnification formula?

  Image size is how large the object appears when magnified.
• What does "Actual size" represent in the magnification formula?

  Actual size is the real, unmagnified size of the object being observed.
• How do you calculate the image size using the magnification formula?

  Image size can be calculated using the formula: Image size = Magnification × Actual size.
• If a cell has an actual size of 10 μm and is viewed under a magnification of 400, what is the image size?


  The image size would be $400 \times 10 \, \mu m =$$4000 \, \mu m \text{ or } 4 \, mm$.