1042SCG Genetics & Evolutionary Biology – Module 1 Lecture 1 Vocabulary

Vocabulary flashcards summarising key terms from Module 1 Lecture 1 on course overview, cell structure, genetic information flow, and mitosis.

Genetics

The study of heredity and the variation of inherited characteristics.

Evolutionary Biology

Branch of biology that studies the processes that produced the diversity of life, including natural selection and genetic drift.

Gene

A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA.

Genome

The complete set of an organism’s DNA; all of its genetic material.

Chromosome

A DNA molecule packaged with proteins; in eukaryotes, usually linear and multiple, in prokaryotes, generally a single circular molecule.

Chromatid

One of two identical halves of a duplicated chromosome, joined at a centromere.

Homologous Chromosomes

A pair of chromosomes, one maternal and one paternal, that have the same genes at the same loci.

Diploid (2n)

Cell or organism with two sets of homologous chromosomes.

Haploid (n)

Cell with one set of chromosomes, typical of gametes.

Polyploid

Having more than two complete sets of chromosomes (e.g., triploid, tetraploid).

Ploidy

The number of sets of chromosomes in a cell.

Karyotype

An image displaying the number and appearance of chromosomes in a cell.

Central Dogma

Concept that genetic information flows DNA → RNA → protein.

Transcription

The synthesis of RNA using a DNA template, occurs in the nucleus of eukaryotes.

Translation

The synthesis of a polypeptide using the information encoded in mRNA, occurs on ribosomes.

DNA

Deoxyribonucleic acid; double-stranded helix storing genetic information.

RNA

Ribonucleic acid; single-stranded nucleic acid involved in protein synthesis and regulation.

Ribosome

Protein-RNA complex that carries out translation; may be free in cytosol or bound to rough ER.

Rough Endoplasmic Reticulum (Rough ER)

ER studded with ribosomes; site of synthesis of proteins destined for secretion or membranes.

Smooth Endoplasmic Reticulum (Smooth ER)

ER lacking ribosomes; functions in lipid synthesis and detoxification.

Golgi Apparatus

Stack of flattened membranes that modifies, sorts, and packages proteins and lipids.

Mitochondrion

Organelle that generates ATP through cellular respiration.

Lysosome

Membrane-bound sac containing hydrolytic enzymes for intracellular digestion.

Peroxisome

Organelle that breaks down fatty acids and detoxifies harmful compounds using oxidative reactions.

Nucleus

Membrane-bound organelle housing eukaryotic DNA and the site of transcription.

Nuclear Pore

Protein channel in the nuclear envelope allowing regulated transport of molecules between nucleus and cytoplasm.

Cytoskeleton

Network of protein filaments (microfilaments, intermediate filaments, microtubules) that support cell shape and movement.

Centrosome

Microtubule-organizing center containing a pair of centrioles in animal cells.

Centriole

Cylindrical structure within the centrosome; helps form the mitotic spindle.

Spindle Fibers

Microtubules that segregate chromosomes during mitosis and meiosis.

Cell Cycle

Ordered sequence of events in a cell’s life: G1, S, G2, and M phases.

Interphase

Portion of the cell cycle (G1, S, G2) in which the cell grows and replicates DNA.

G1 Phase

First gap phase; cell growth and normal metabolism occur.

S Phase

DNA synthesis phase; entire genome is replicated.

G2 Phase

Second gap phase; cell grows, repairs DNA, and duplicates centrosomes in preparation for mitosis.

Mitosis

Eukaryotic cell division that produces two genetically identical daughter cells.

Prophase

First mitotic stage; chromosomes condense, spindle begins to form, nuclear envelope intact.

Prometaphase

Nuclear envelope fragments; spindle microtubules attach to kinetochores on chromosomes.

Metaphase

Chromosomes align at the metaphase plate; spindle fully formed.

Anaphase

Sister chromatids separate and move toward opposite spindle poles.

Telophase

Chromosomes decondense, nuclear envelopes re-form around daughter nuclei.

Cytokinesis

Division of the cytoplasm, forming two separate daughter cells.

Cleavage Furrow

Contractile ring of actin microfilaments that pinches animal cells during cytokinesis.

Binary Fission

Asexual division of prokaryotic cells; involves genome replication, cell elongation, and septum formation.

Origin of Replication

Specific DNA sequence where replication initiates; single origin in prokaryotes, multiple in eukaryotes.

Prokaryote

Unicellular organism lacking a nucleus and membrane-bound organelles (bacteria, archaea).

Eukaryote

Organism whose cells contain a nucleus and membrane-bound organelles.

Recombinant DNA Technology

Manipulation of DNA molecules to study or modify genes, including cloning and PCR.

Polymerase Chain Reaction (PCR)

Technique to amplify a specific DNA segment exponentially in vitro.

Microevolution

Small-scale changes in allele frequencies within a population over generations.

Macroevolution

Large-scale evolutionary changes that give rise to new species or groups.