Study guide: Cells and Microscopy

📋 Course Outline

1. Microscope Parts and Uses
2. Hooke and the Discovery of Cells
3. Plant and Animal Cell Types
4. Cell Processes and Diffusion
5. Cell Size and Magnification
6. Animal Cell Structures
7. Investigating Diffusion Rate
8. Sperm Cell Adaptations

📖 1. Microscope Parts and Uses

★ Must-know

• Turning the focus knob makes a blurred specimen look clearer.

Further detail

• The eyepiece is where the scientist looks to observe the specimen.

• The objective lens magnifies the specimen through three lenses.

• The specimen is placed on the stage for magnification.

📖 2. Hooke and the Discovery of Cells

📝 Essential Points

• Robert Hooke used a microscope to look at a thin slice of cork.

• Robert Hooke called the tiny room-like structures he saw in cork cells.

• All organisms are made up of cells.

📖 3. Plant and Animal Cell Types

★ Must-know

📌 Red blood cells, nerve cells, sperm cells, and egg cells are animal cells, whereas root hair cells and leaf cells are plant cells.

Further detail

• Amoebas are protists.

📖 4. Cell Processes and Diffusion

🔑 Key Concepts & Definitions

• Diffusion: The movement of substances from a region of higher concentration to a region of lower concentration.
• Binary fission: How an amoeba reproduces.

★ Must-know

📌 Photosynthesis makes food from sunlight, whereas respiration releases energy from food.

Further detail

• Animal cells usually take in oxygen and let out carbon dioxide.

📖 5. Cell Size and Magnification

📝 Essential Points

• The size order from smallest to largest is mitochondrion, human sperm cell, human egg cell, and human embryo.

📐 Formula - Total magnification equals eyepiece magnification multiplied by objective lens magnification: $M_{total}=M_{eyepiece}\times M_{objective}$.

📖 6. Animal Cell Structures

🔑 Key Concepts & Definitions

• Nucleus: Stores the genetic material.
• Mitochondrion: Where respiration takes place.
• Cytoplasm: The jelly-like substance where chemical reactions take place.
• Cell membrane: The barrier around the cell that lets substances move across it.

📖 7. Investigating Diffusion Rate

📝 Essential Points

• A diffusion investigation can measure an independent variable and a dependent variable, with suitable units and a sensible range of measurements.

• In Theo's diffusion setup, a 1 cm³ cube of red gel is placed at the centre of clear gel in a Petri dish with a diameter of 10 cm.

📖 8. Sperm Cell Adaptations

📝 Essential Points

• A sperm cell's tail, streamlined head, and many mitochondria are adaptations that suit it to its job.