Light Microscopy, Cells, and The Cell Cycle – Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering light microscopy, the structure and function of the compound microscope, basic cell theory and components, the cell cycle, mitosis, and various cell types.

Light Microscopy

Any kind of microscope that uses visible light to observe specimens.

Compound Light Microscope

A microscope that uses objective and ocular lenses; the ocular magnifies the image produced by the objective; total magnification is the product of the two lens powers.

Resolution (Resolving Power)

The ability of lenses to distinguish two points as separate.

Refractive Index

A measure of how much a medium bends (refracts) light.

Immersion Oil

Oil used with an oil-immersion objective to reduce refraction and improve resolution.

Ocular Lens (Eyepiece)

The lens you look through; it magnifies the image formed by the objective.

Objective Lens

Primary lenses that magnify the specimen; available in multiple powers (e.g., 4x, 10x, 40x, 100x).

Stage

The platform that holds the microscope slide in place.

Condenser

Focuses light through the specimen to illuminate it.

Diaphragm

Controls the amount of light entering the condenser.

Illuminator

The light source of the microscope.

Coarse Focusing Knob

Roughly moves the stage or objective to bring the specimen into general focus.

Fine Focusing Knob

Precisely focuses the image once rough focus is achieved.

Arm

Part of the microscope that supports the head and connects to the base.

Base

The bottom support of the microscope.

Body Tube

Transmits the image from the objective lens to the ocular lens.

Revolving Nosepiece

Rotating turret that holds multiple objective lenses for different magnifications.

Path of Light

The route light takes from the illuminator through the specimen to the eyepiece.

Metaphase Plate

The imaginary plane at the cell’s equator where chromosomes align during metaphase.

Chromatin

Uncondensed DNA-protein material present in interphase.

Chromosome

A threadlike structure containing DNA; consists of two sister chromatids held at the centromere.

Sister Chromatid

One of the two identical copies of a replicated chromosome held at the centromere before separation.

Centromere

Region of a chromosome where sister chromatids are held together and where kinetochores attach.

Kinetochore

Protein structure at the centromere that attaches to spindle microtubules during mitosis.

Mitotic Spindle

Array of microtubules that moves chromosomes during mitosis.

Aster

Radial array of microtubules extending from the centrosome during early mitosis.

Centrosome

Organsing center of microtubules; in animal cells, contains two centrioles and organizes the spindle.

Prophase

First stage of mitosis; chromosomes condense, centrosomes move to poles, spindle forms, nucleolus disappears.

Late Prophase

Nuclear envelope breaks down; kinetochores attach spindle fibers to chromosomes.

Metaphase

Chromosomes align at the metaphase plate with centromeres at the equator.

Anaphase

Centromeres split; sister chromatids separate and are pulled toward opposite poles; poles are pushed farther apart.

Telophase

Chromosomes arrive at poles, uncoil, and new nuclear envelopes form; nucleoli reappear; spindle disassembles.

Cytokinesis

Division of the cytoplasm; contracts to form a cleavage furrow, yielding two separate daughter cells.

Mitosis

Nuclear division that distributes replicated chromosomes into two identical daughter nuclei, usually followed by cytokinesis.

Interphase

Period of the cell cycle when the cell grows, copies DNA, and carries out normal activities; not part of mitosis.

G1 Phase

Gap 1; cell grows and carries out metabolism; cells may enter G0 if they permanently cease dividing.

S Phase

Synthesis; DNA replication occurs.

G2 Phase

Gap 2; preparation for division.

Cell Cycle

Series of events from cell formation to division, including interphase and mitotic (M) phase.

G0 Phase

A state in which cells have permanently ceased dividing and no longer progress through the cell cycle.

DNA Replication

The process of copying the cell’s DNA during S phase.

Plasma Membrane

Flexible outer boundary of the cell that regulates what enters and leaves.

Cytoplasm

Intracellular fluid containing organelles; site of many metabolic activities.

Nucleus

DNA-containing control center of the cell.

Generalized Cell

A typical cell model with three basic parts: plasma membrane, cytoplasm, and nucleus.

Fibroblast

A connective tissue cell that synthesizes extracellular matrix and collagen.

Erythrocyte (Red Blood Cell)

A cell that carries oxygen in the blood.

Skeletal Muscle Cell

A muscle cell responsible for voluntary movement.

Epithelial Cell

A cell that lines surfaces and forms barriers; may participate in absorption, secretion, and protection.

Fat Cell (Adipocyte)

A cell that stores fat in adipose tissue.

Nerve Cell (Neuron)

A cell that transmits electrical signals in the nervous system.

Macrophage

A phagocytic white blood cell that ingests pathogens and debris.

Sperm

Male gamete that carries paternal DNA.

Smooth Muscle Cell

Involuntary muscle cell found in hollow organs and vessels; facilitates movement of contents.