General Biology 1 Midterm Review – Cells, Organelles & Cell Processes

Vocabulary flashcards summarizing essential terms and definitions for the General Biology 1 midterm on cells, organelles, cell cycle, and membrane structure.

Cell Theory

Biological principle stating that all living things are composed of cells, cells are the basic units of life, and all cells arise from pre-existing cells.

Robert Hooke

1665 scientist who coined the word “cells” after observing cork under a microscope.

Anton van Leeuwenhoek

1674 scientist who viewed living “animalcules” in pond water with an improved microscope.

Matthias Schleiden

1838 botanist who concluded that all plants are made of cells.

Theodor Schwann

1839 zoologist who stated that all animals are composed of cells.

Rudolf Virchow

1855 pathologist who asserted that all cells come from pre-existing cells.

Cell Membrane

Semi-permeable phospholipid bilayer that regulates entry and exit of substances.

Cytoplasm

Gel-like fluid inside cells where organelles are suspended.

Nucleus

Membrane-bound organelle that houses DNA and controls cellular activities.

Mitochondria

“Powerhouse” organelles that generate ATP through cellular respiration.

Ribosomes

Tiny structures responsible for protein synthesis.

Endoplasmic Reticulum (ER)

Membranous network that transports materials; rough ER has ribosomes for protein production, smooth ER synthesizes lipids.

Golgi Apparatus

Organelle that modifies, packages, and ships proteins and lipids.

Vacuole

Membrane sac for storage of water, food, or waste; large and central in plant cells.

Lysosome

Enzyme-filled vesicle that breaks down waste and cellular debris; abundant in animal cells.

Cell Wall

Rigid outer layer made of cellulose that provides support and protection in plant cells.

Chloroplast

Green organelle where photosynthesis occurs in plant cells.

Plant Cell

Eukaryotic cell with a cell wall, chloroplasts, and large central vacuole.

Animal Cell

Eukaryotic cell lacking a cell wall but rich in lysosomes and small vacuoles.

Prokaryotic Cell

Simple cell without a true nucleus or membrane-bound organelles; exemplified by bacteria and archaea.

Eukaryotic Cell

Complex cell containing a nucleus and membrane-bound organelles; found in plants, animals, fungi, and protists.

Root Hair Cell

Plant cell with long extensions that increase surface area for water absorption.

Sperm Cell

Motile male gamete equipped with a flagellum and many mitochondria for movement toward the egg.

Red Blood Cell

Biconcave, anucleate cell specialized for transporting oxygen using hemoglobin.

Ciliated Cell

Epithelial cell with hair-like cilia that move mucus and debris out of passages such as the trachea.

Cell Cycle

Ordered series of events a cell goes through for growth and division, including interphase and mitotic phases.

Interphase

Longest phase of the cell cycle consisting of G1, S, and G2 stages where the cell grows and replicates DNA.

G1 Phase

First gap stage of interphase marked by cell growth and preparation for DNA replication.

S Phase

Synthesis stage of interphase during which DNA is replicated.

G2 Phase

Second gap stage where the cell prepares for mitosis, checking DNA for errors.

Mitosis

Division of a somatic cell nucleus into two genetically identical daughter nuclei (PMAT).

Cytokinesis

Division of the cytoplasm following mitosis, producing two separate daughter cells.

Prophase

Mitotic stage where chromatin condenses, nuclear envelope dissolves, and spindle fibers form.

Metaphase

Mitotic stage where chromosomes align at the cell’s equatorial plane.

Anaphase

Mitotic stage where sister chromatids separate and move to opposite poles.

Telophase

Mitotic stage where chromosomes decondense and nuclear membranes reform at each pole.

Meiosis

Two-stage cell division in gametes producing four haploid, genetically diverse cells.

Synapsis

Pairing of homologous chromosomes during Prophase I of meiosis.

Crossing Over

Exchange of genetic material between homologous chromosomes during Prophase I, leading to variation.

Diploid (2n)

Cell with two sets of chromosomes—full complement typical of somatic cells.

Haploid (n)

Cell with one set of chromosomes—typical of gametes.

Fluid Mosaic Model

1972 description of the cell membrane as a fluid lipid bilayer with embedded proteins forming a mosaic.

Phospholipid Bilayer

Double layer of phospholipids with hydrophilic heads outward and hydrophobic tails inward, forming the membrane’s framework.

Integral Protein

Protein that spans the phospholipid bilayer, often functioning as channels or transporters.

Peripheral Protein

Protein attached to the membrane surface involved in signaling or structural support.

Glycoprotein

Protein with an attached carbohydrate chain used for cell recognition.

Glycolipid

Lipid with an attached carbohydrate chain, also involved in cell recognition.

Cholesterol (in membranes)

Lipid molecule that stabilizes membrane fluidity by preventing extremes of rigidity or fluidity.