Biology 1 - Microscopes, Cells, Cell Theory, Meiosis & Mitosis, and Cellular Transport (Vocabulary Flashcards)

A comprehensive set of vocabulary flashcards covering microscopes, cells, cell theory, specialized cells, the cell cycle (mitosis & meiosis), and cellular transport.

Microscope

A scientific instrument that magnifies objects to reveal details not visible to the naked eye.

Light Microscope

An optical microscope that uses lenses to focus visible light on specimens to magnify them.

Magnification

The apparent enlargement of an object, produced by objective and eyepiece lenses (e.g., 100x × 10x = 1000x).

Resolution

The ability to distinguish fine detail; how well two close objects can be seen as separate.

Contrast

The difference in brightness between the specimen and its background, often enhanced by staining.

Head (body)

The upper part of a microscope that contains the optical components.

Base

The bottom support of the microscope; may contain the illumination source.

Arm

The component that connects the base to the head and stage; used to carry the microscope.

Eyepiece

The lens through which you look to view the specimen.

Eyepiece Tube

The tube that holds the eyepiece and is mounted above the objective lens.

Objective Lenses

Primary lenses (e.g., 40x–100x) used to form the initial magnified image.

Nosepiece

Rotating part that holds multiple objective lenses and selects magnification.

Coarse Adjustment Knob

Large knob for coarse focus adjustment.

Fine Adjustment Knob

Small knob for precise focusing.

Stage

Platform where the slide sits; held by stage clips.

Stage Clips

Clips that secure the slide on the stage.

Illuminator

Light source at the base that provides illumination for viewing.

Condenser

Lenses under the stage that focus light through the specimen.

Diaphragm

Controls the amount of light reaching the specimen.

Electron Microscope

A microscope that uses a beam of accelerated electrons for high-resolution images.

Electron Gun

A heated filament that emits electrons.

Electromagnetic Lenses

Magnetic lenses that focus the electron beam (condenser, objective, projector/ocular).

Specimen Holder

A very thin film support (carbon/collodion on a grid) for the specimen.

Image Viewing and Recording System

Display and recording setup (fluorescent screen and camera) for the final image.

Ernst Ruska

German engineer who built the first electron microscope in 1931.

Hans Janssen

Dutch father who, with his son, helped develop early microscopes by combining lenses.

Zacharias Janssen

Dutch son who collaborated on early microscope creation.

Antonie van Leeuwenhoek

Dutch scientist who built a simple microscope and observed bacteria and protozoa (animalcules).

Cells

The fundamental unit of life; basic structural and functional unit of living organisms.

Cell Theory

Idea that organisms are composed of cells; cells are the basic units of life; all cells arise from preexisting cells.

Postulates

Three original cell theory statements: all organisms are made of cells; cells are the basic unit of life; all cells come from preexisting cells.

DNA

Deoxyribonucleic acid; hereditary material passed between cells.

Nucleus

The control center of the cell containing DNA and regulating cellular activities.

Nucleolus

Dense region inside the nucleus that produces ribosomes.

Cytoplasm

Jelly-like interior of the cell that houses organelles.

Mitochondria

Powerhouses of the cell; generate ATP (cellular energy).

Ribosomes

Tiny particles that synthesize proteins.

Endoplasmic Reticulum (ER)

Membrane network for protein and lipid synthesis; Rough ER has ribosomes; Smooth ER lacks ribosomes.

Golgi Apparatus

Organelle that sorts, modifies, and packages proteins and lipids for transport.

Lysosomes

Digestive organelles that break down waste and worn-out parts.

Cytoskeleton

Network of protein filaments providing structure, shape, and transport within the cell.

Centrioles

Structures involved in organizing microtubules during cell division.

Vesicle

Small sacs that transport materials inside the cell or to the membrane.

Cell Membrane

Semi-permeable boundary that controls entry and exit of substances.

Chloroplasts

Plant organelles where photosynthesis occurs; contain chlorophyll.

Cell Wall

Rigid outer layer (mainly cellulose in plants) providing support and protection.

Plastids

Plant organelles involved in storage and manufacturing of food; includes chloroplasts.

Prokaryotic Cell

Single-celled organism lacking a membrane-bound nucleus and other organelles; divide by binary fission (e.g., bacteria).

Capsule

Protective outer layer in some bacteria that aids moisture retention and adherence.

Pili

Hair-like structures on bacteria that help attach to surfaces.

Fimbriae

Shorter appendages (pili) that help bacteria attach to surfaces.

Flagella

Long, whip-like structures that enable bacterial movement.

Plasmids

Small, circular DNA molecules outside the chromosome that carry genes.

Nucleoid

Region in a prokaryotic cell containing the single circular chromosome.

Red Blood Cell

Disc-shaped, anucleate cell in mammals that carries hemoglobin for oxygen transport.

Root Hair Cell

Plant root cell with elongated extensions to increase surface area for absorption.

Xylem

Plant tissue that transports water and minerals; composed of lignified, dead cells.

Phloem

Plant tissue that transports sugars; includes sieve tubes and companion cells.

Guard Cells

Cells that regulate stomatal opening via changes in turgor pressure.

Palisade Cell

Photosynthetic plant cell rich in chloroplasts and oriented to maximize light absorption.

Sperm Cell

Male gamete; contains acrosome on head and mitochondria in the tail; fertilizes the egg.

Egg Cell

Large female gamete rich in nutrients; contributes half the genetic material.

Ciliated Cells

Cells bearing cilia that move mucus or eggs through passages.

Meiosis

Cell division that reduces chromosome number from diploid to haploid to form gametes.

Mitosis

Nuclear division producing two genetically identical diploid daughter cells.

Interphase

Longest cell cycle stage; cell grows and DNA is replicated.

G1 Phase

First gap phase; cell growth and normal metabolism occur.

S Phase

DNA synthesis and replication; sister chromatids form.

G2 Phase

Second gap phase; further growth and preparation for division; DNA checked.

Prophase

Chromosomes condense; nuclear envelope dissolves; spindle forms.

Metaphase

Chromosomes align at the cell equator; spindle fibers attach to centromeres.

Anaphase

Sister chromatids separate and move to opposite poles.

Telophase

Chromosomes arrive at poles and decondense; new nuclear envelopes form.

Cytokinesis

Division of the cytoplasm, producing two distinct daughter cells.

Crossing Over

Exchange of DNA between homologous chromosomes in Prophase I, increasing genetic variation.

Non-Disjunction

Failure of chromosome/chromatid separation during meiosis, producing abnormal gametes.

Down Syndrome

Trisomy 21; an extra chromosome 21 in each cell.

Turner Syndrome

45,X; monosomy of the X chromosome in females.

Klinefelter Syndrome

47,XXY; male with extra X chromosome.

Cri du Chat

Deletion on chromosome 5 leading to a characteristic cry and developmental issues.

Osmosis

Diffusion of water across a selectively permeable membrane from hypotonic to hypertonic solutions.

Diffusion

Movement of particles from high to low concentration due to random motion.

Isotonic

Solution with equal solute concentration to the cell’s cytoplasm; no net water movement.

Hypertonic

Solution with higher solute concentration than the cell’s cytoplasm; water leaves the cell.

Hypotonic

Solution with lower solute concentration than the cell’s cytoplasm; water enters the cell.

Facilitated Diffusion

Passive transport of molecules via membrane proteins down the concentration gradient.

Channel Proteins

Membrane proteins forming pores for specific ions or molecules to pass.

Carrier Proteins

Membrane proteins that bind a molecule and shuttle it across the membrane.

Active Transport

Movement of solutes against the concentration gradient requiring energy (ATP).

ATP

Adenosine triphosphate; the energy currency of the cell.

Endocytosis

Cellular uptake of materials by engulfing them with the plasma membrane.

Phagocytosis

Endocytosis of solid material (cellular eating) by engulfment.

Pinocytosis

Endocytosis of liquids (cellular drinking) via vesicle formation.