Light Microscope and Cell Biology Practice Flashcards

This set of flashcards covers light microscope anatomy and usage, cell types (prokaryotic vs. eukaryotic), cellular organelles, specialized cells in plants and animals, and the mechanics of the cell cycle, mitosis, and meiosis.

Light Microscope

A device that uses visible light and a system of lenses to magnify small objects that are not visible to the naked eye.

Eyepiece (Ocular Lens)

The lens you look through, usually containing a magnification of $10\times$.

Nosepiece

The part that holds the objective lenses and rotates to change magnification.

Objective Lenses

Primary lenses that magnify the specimen, with ranges such as $4\times$, $10\times$, $40\times$, and $100\times$.

Stage

The platform that supports the slide being viewed.

Stage Clips

Components used to hold the slide in place on the stage.

Diaphragm

A part that regulates or controls the amount of light passing through the specimen.

Coarse Adjustment Knob

A knob used for rough focusing by moving the stage up or down quickly.

Fine Adjustment Knob

A knob used for sharp, clear focus by moving the stage slightly.

Arm

The part that supports the upper parts of the microscope and is used for carrying it.

Illuminator (Light Source)

Provides or reflects light upwards through the diaphragm, specimen, and lenses.

Base

The bottom part of the microscope that provides stability and support.

Cell

The basic and fundamental unit of life, possessing a highly organized structure to carry out vital functions.

Prokaryotes

Simple, unicellular organisms from kingdoms Archaea and Bacteria that lack a nucleus and membrane-bound organelles.

Eukaryotes

Organisms (Protists, Fungi, Plants, Animals) whose cells have a nucleus enclosed by a membrane and other membrane-bound organelles.

Nucleoid

The region in a prokaryotic cell where most of its DNA is found.

Cell Membrane

A selective barrier that surrounds the cell, regulating the passage of nutrients and waste materials.

Cell Nucleus

An organelle in the center of eukaryotic cells that houses DNA, safeguarding genetic information and controlling gene expression.

Nucleolus

A structure located inside the nucleus involved in ribosome synthesis.

Cytoplasm

A gel-like matrix containing water, salts, and proteins that occupies the space between the cell membrane and the nucleus.

Ribosome

The site of protein synthesis found in both prokaryotic and eukaryotic cells.

Rough Endoplasmic Reticulum (RER)

A network of membranes studded with ribosomes involved in the synthesis and modification of proteins.

Smooth Endoplasmic Reticulum (SER)

A network of membranes specializing in lipid synthesis, carbohydrate metabolism, and detoxification.

Golgi Apparatus

The cell's "shipping center" that modifies, sorts, and packages proteins and lipids for transport.

Mitochondria

Known as the "powerhouse of the cell," it produces energy ($ATP$) through cellular respiration.

Chloroplasts

Organelles in plants and algae containing chlorophyll that convert light energy into chemical energy (glucose) via photosynthesis.

Lysosomes

Organelles that break down waste and damaged cell parts for recycling.

Peroxisomes

Organelles that break down fatty acids and detoxify harmful substances.

Cytoskeleton

A structure made of protein fibers (microtubules and microfilaments) that provides shape and structural support.

Flagella

Long, hair-like structures used for movement, usually numbering one or a few per cell.

Cilia

Short, numerous hair-like structures used for movement or moving substances across the cell surface.

Vacuoles

Storage sacs for water, nutrients, and waste; they help maintain turgor pressure in plant cells.

Vesicles

Small membrane-bound sacs used for transporting and storing materials within the cell.

Endosomes

Membrane-bound compartments involved in sorting and processing materials taken in through endocytosis.

Red Blood Cell

An animal cell specialized to carry oxygen ($O_2$) with a biconcave shape and no nucleus.

White Blood Cell

An irregular-shaped animal cell that plays a role in the immune system by producing antibodies and antitoxins.

Sperm Cell

A specialized cell for fertilizing an egg, featuring a long tail for swimming and numerous mitochondria.

Nerve Cell (Neuron)

A cell adapted to carry nerve impulses with a long, thin axon and branching dendrites.

Guard Cell

A plant cell that regulates the rate of transpiration and has a cell wall with varying thickness.

Xylem Vessel

Plant cells with lignin and no protoplasm that form continuous tubes to transport water and minerals.

Cell Cycle

The series of events involving growth, DNA replication, and division into two identical daughter cells.

Interphase

The preparation stage taking up approximately $90\%$ of the cell cycle, consisting of $G_1$, $S$, and $G_2$ phases.

$S$ Phase (Synthesis)

The specific stage of interphase where DNA is replicated and chromosomes are copied.

Mitosis

Nuclear division that results in two nuclei with identical genetic information, occurring in somatic cells.

Cytokinesis

The division of the cytoplasm that produces two separate daughter cells.

Chromatin

Loose genetic material consisting of DNA threads wrapped around histone proteins inside the nucleus.

Centromere

The region that holds sister chromatids together and attaches to spindle fibers.

Centrioles

Paired organelles that organize spindle fibers and move to opposite poles during mitosis.

Prophase

The phase of mitosis where chromosomes become visible, the nuclear membrane breaks down, and spindle fibers form.

Metaphase

The phase of mitosis where chromosomes line up at the center (metaphase plate) and spindle fibers attach to centromeres.

Anaphase

The phase of mitosis where sister chromatids separate and move toward opposite poles.

Telophase

The phase of mitosis where the nuclear membrane reforms, chromosomes uncoil, and two nuclei are formed.

Meiosis

A type of cell division in reproductive cells that produces four genetically different haploid daughter cells.

Haploid ($n$)

Cells containing half the number of chromosomes of the parent cell, such as the $23$ chromosomes in human gametes.

Synapsis

The process during Prophase I where homologous chromosomes pair up.

Crossing-over (Recombination)

The exchange of genetic material between homologous chromosomes that contributes to genetic variability.

Gametogenesis

The process of producing gametes; includes spermatogenesis in males and oogenesis in females.

Polar Bodies

The three non-functional cells produced during oogenesis, while only one functional ovum is created.

Zygote

The diploid ($2n$) cell formed when haploid gametes unite through fertilization.