Grade 10 Life Sciences: Microscope and Cell Biology

Vocabulary flashcards covering the history of microscopy, microscope parts and functions, cell theory, biological levels of organization, measurement units, and cell organelle structure and function based on the Grade 10 Life Sciences curriculum.

Robert Hooke ($1635$-$1703$)

Scientist who in $1665$ used a basic microscope to observe cork, saw 'row of empty boxes', and coined the term cell.

Antonie van Leeuwenhoek ($1632$-$1723$)

Developed the first microscope in $1676$ used to study bacteria and various micro-organisms.

Robert Brown ($1773$-$1858$)

Explained the structure of organelles within the cell.

Ernst Haeckel ($1834$-$1919$)

Wrote about chromatin and hereditary characteristics.

Light Microscope

Uses visible light and magnifying lenses to examine small specimens not visible to the naked eye.

Base

Part of the microscope that supports it on the work surface, eliminates vibrations, and is used for carrying.

Body tube

Part of the microscope used to hold or support the optical parts.

Stage

Supports the slide and contains an aperture that allows light from the source to pass through the specimen.

Coarse focusing knob

Used to bring the specimen into focus on low power ONLY.

Fine focusing knob

Used to bring objects into sharper focus on all powers and can focus on parts at different depths.

Condenser

Part used to condense or focus the light from the light source onto the specimen.

Diaphragm

Regulates the amount of light going from the light source through the stage aperture.

Objectives

Lenses used to magnify the specimen by $4x$, $10x$, or $40x$.

Eye piece (Ocular)

The lens you look through to see the specimen; it magnifies the specimen $10x$.

Total magnification formula

$\text{Magnification of ocular lens} \times \text{Magnification of objective lens} = \text{Total Magnification}$.

Mounting fluid

Liquid such as water or dye used when making a wet mount slide.

Irrigating a slide

Process of adding more dye to a specimen after the slide is made using a dropper and blotting paper.

Cell Theory

States all living things are made of cells, the cell is the smallest living unit of structure and function, and all cells arise from pre-existing cells.

Theodor Schwann & Matthias Schleiden ($1839$)

Scientists who proposed that all living things are made of cells.

Rudolf Virchow

Scientist who stated that 'all cells come from cells'.

Tissues

Groups of similar cells working together to perform a common function, such as muscle or bone tissue.

Organs

Groups of different tissues working together to perform a common function, such as the heart or stomach.

Systems

Groups of different organs working together to perform a common function, such as the respiratory or digestive system.

Micrometre ($\mu m$)

Unit of measurement for cells where $1000\, \mu m = 1\, mm$.

Nanometre ($nm$)

Unit of measurement where $1000\, nm = 1\, \mu m$.

True/Actual Size Formula

$$\frac{\text{Measured size (mm)} \times 1000}{\text{Magnification}}$$

Protoplasm

Includes all the living parts of the cell, such as the nucleus, cell membrane, cytoplasm, and all organelles.

Cell wall

A firm, rigid, non-living part of plant cells made of cellulose that provides support and prevents the cell from bursting.

Cell membrane

A selectively permeable structure consisting of phospholipids, proteins, and carbohydrates, represented by the fluid mosaic model.

Cytoplasm

The part of the protoplasm outside the nucleus, consisting of $80\%$ water, which can change from sol to gel state.

Cyclosis

The process by which substances are circulated within the cell through the cytoplasm.

Nucleus

The biggest organelle and control center of the cell, containing genetic information and controlling mitosis and meiosis.

Chromatin

Long strands of DNA found in the nucleus when the cell is not dividing.

Chromosomes

Short, thick structures formed when chromatin shortens during cell division.

Nucleolus

A dark body in the nuclear plasma made of RNA and proteins that makes ribosomes and stores RNA.

Nuclear pores

Openings in the double nuclear membrane that allow large molecules to move in or out of the nucleus.

Mitochondria

Oval-shaped organelles that provide energy (ATP) for the cell through cellular respiration.

Cristae

Folds in the inner membrane of a mitochondrion that increase surface area for respiration enzymes.

Matrix

Fluid filling the inside of the mitochondrion containing ribosomes, DNA, and enzymes.

Ribosomes

Minute, dense bodies composed of RNA that synthesize proteins; found on rough ER or free in cytoplasm.

Endoplasmic Reticulum (ER)

A system of double membranes used for communication, transport, and dividing the cytoplasm into regions.

Golgi body (Dictyosome)

Formed from the ER, it consists of flattened membranes that collect and package secretory substances into vesicles.

Plastids

Large organelles found only in plant cells that contain pigments or food substances; includes chromoplasts, leucoplasts, and chloroplasts.

Chloroplasts

Green plastids containing chlorophyll used for photosynthesis to produce glucose.

Thylakoids

Saucer-like structures inside chloroplasts containing chlorophyll; arranged in stacks called grana.

Leucoplasts

Colourless organelles functioning to store starch, found in organs like potato tubers.

Stroma

The liquid medium surrounding the grana and intergrana in a chloroplast.

Tonoplast

The single membrane surrounding a vacuole.

Cell sap

Fluid inside a vacuole consisting of water with dissolved sugars and salts.

Osmosis

The movement of water from high water potential to low water potential through a semi-permeable membrane.

Turgor pressure

The outwards pushing force of the vacuole against the cell wall when a plant cell is turgid.

Plasmolysed

The state of a cell when water leaves the vacuole and the cell becomes flaccid.

Lysosomes

Single-membrane bags containing hydrolytic enzymes that destroy foreign bodies or worn-out organelles.

Centrosome

An area in animal cells containing two centrioles that form spindle fibres during cell division.

Passive transport

Movement along a concentration gradient (high to low) through pores that does not require ATP.

Active transport

Movement against a concentration gradient (low to high) controlled by carrier proteins that requires ATP.

Water potential ($\psi$)

The ability or kinetic energy of water molecules to move from one area to another.

Hypotonic solution

A solution where the amount of solutes outside is less than inside the cell, causing water to flow into the cell.

Hypertonic solution

A solution where the amount of solutes outside is greater than inside the cell, causing water to flow out of the cell.

Isotonic solution

A solution where the amount of solutes are equal inside and outside the cell.