Lecture 14: Cell Cycle & Mitosis

Cell Cycle

The series of events that a cell goes through as it grows and divides.

Mitosis

A process of cell division that results in two genetically identical daughter cells from a single parent cell.

Interphase

The phase of the cell cycle where the cell spends most of its life performing its normal functions, including G1, S, and G2 phases.

G1 Phase

The first gap phase of the cell cycle where the cell grows and performs its normal functions.

S Phase

The synthesis phase of the cell cycle where DNA is replicated, resulting in two sister chromatids for each chromosome.

G2 Phase

The second gap phase that follows DNA synthesis, where the cell checks for errors in DNA and prepares for mitosis.

M Phase

The mitotic phase of the cell cycle during which mitosis and cytokinesis occur.

Cytokinesis

The process during cell division in which the cytoplasm of a parent cell is divided into two daughter cells.

Sister Chromatids

Identical copies of a chromosome that are joined together by the centromere.

Centromere

The region of a chromosome where the two sister chromatids are joined.

Checkpoint

A point in the cell cycle where the cell assesses whether to proceed with division.

HeLa Cells

A type of immortal cell line used in scientific research, derived from cervical cancer cells.

Nucleus

The membrane-bound organelle that contains a cell's genetic material and controls its activities.

G0 Phase

A non-dividing state where a cell exits the cell cycle but remains metabolically active.

Cyclins

A group of proteins that regulate the cell cycle by activating cyclin-dependent kinases.

Cyclin-Dependent Kinases (CDKs)

Enzymes that, when activated by cyclins, drive the cell past various checkpoints in the cell cycle.

Apoptosis

Programmed cell death that occurs when cells are damaged or no longer needed.

Gametes

Reproductive cells (sperm and eggs) that are produced through meiosis.

Zygote

The fertilized egg that forms after the fusion of a sperm cell and an egg cell.

Trisomy

A genetic condition in which an individual has three copies of a chromosome instead of the normal two.

Blastocyst

A structure formed in the early development of mammals, consisting of a hollow ball of cells.

Plasmodesmata

Channels that allow communication and transport between plant cells.

Gene Expression

The process by which information from a gene is used to synthesize a functional gene product, typically a protein.

Nucleolus

A dense region within the nucleus where ribosomal RNA (rRNA) is synthesized.

Microtubules

Cytoskeletal structures that play roles in cell shape, transport, and the separation of chromosomes during cell division.

Anaphase

The stage of mitosis where sister chromatids are pulled apart to opposite poles of the cell.

Telophase

The final stage of mitosis where the separated chromosomes reach the poles and the nuclear envelope begins to reform.

Aster

A star-shaped structure formed around each centrosome during mitosis, consisting of microtubules.

Cleavage Furrow

The indentation that begins to form as the cell undergoes cytokinesis, leading to the separation of daughter cells.

Cell Plate

The structure that forms during cytokinesis in plant cells to separate the two daughter cells.

Mitosis Phases

The five stages of mitosis: prophase, prometaphase, metaphase, anaphase, and telophase.

Stem Cells

Undifferentiated cells that can develop into various cell types and are important for growth and repair.

Hematopoietic Stem Cells

Stem cells found in bone marrow that give rise to all blood cells.

Translocation

The process by which a segment of one chromosome breaks off and attaches to another chromosome.

Gene

A segment of DNA that contains the instructions for building a specific protein or functional RNA.

Eukaryotes

Organisms composed of one or more cells that have membrane-bound nuclei and organelles.

Prophase

The first phase of mitosis, during which chromosomes condense and the nuclear envelope begins to break down.

Prometaphase

The stage of mitosis where nuclear envelope breakdown is completed and spindle microtubules attach to kinetochores.

Metaphase

The stage of mitosis in which chromosomes are aligned along the metaphase plate.

Centriole

Small structures within the centrosome that help in the formation of spindle fibers during cell division.

Chloroplasts

Organelles found in plant cells responsible for photosynthesis.

CAMPATH-1H

An example of a monoclonal antibody used in cancer treatment targeting specific cell types.

Epithelial Cells

Cells that line the surfaces of organs and structures throughout the body, often involved in protection and secretion.

Mitotic Spindle

The structure formed by microtubules that segregates chromosomes during cell division.

Motor Proteins

Proteins that move along cytoskeletal filaments and are responsible for transporting materials and moving chromosomes.

Drug Resistance

A condition where cancer cells adapt to resist the effects of certain chemotherapy drugs.

Nuclear Envelope

The double membrane that encloses the nucleus and separates it from the cytoplasm.

Protein Synthesis

The process in which cells use the genetic information in RNA to produce proteins.

Fertilization

The process where a sperm cell and an egg cell fuse to create a zygote.

Regeneration

The process of renewal, restoration, and growth in organisms.

Biogenesis

The principle that living organisms arise from pre-existing life.

Tissues

Groups of cells that work together to perform a specific function.

Ribosomal RNA (rRNA)

RNA component of the ribosome, essential for protein synthesis.

Cell Theory

The theory that states that all living organisms are composed of cells, cells are the basic unit of life, and all cells come from pre-existing cells.

Nexus

A connection or series of connections linking two or more things.

Nuclear Chromatin

A complex of DNA and proteins found in the nucleus of eukaryotic cells that condenses to form chromosomes during cell division.

Somatic Cells

Any cells forming the body of an organism, excluding germ cells.

Environmental Signals

External cues that influence the behavior and functioning of cells.

Cytoskeleton

A network of fibers in the cytoplasm that helps maintain cell shape and plays important roles in cell division.

Endoplasmic Reticulum (ER)

An organelle involved in the synthesis of proteins and lipids.

Golgi Apparatus

An organelle that processes, packages, and distributes proteins and lipids.

Mitochondria

Organelles known as the powerhouses of the cell, generating ATP through respiration.

Cell Wall

A rigid layer surrounding plant cells, providing structure and support.

Gastrulation

The process during embryonic development that forms the three germ layers.

Blastula

An early stage of embryonic development that features a hollow sphere of cells.

Chromosomal Aberration

An abnormality in the structure or number of chromosomes that may lead to genetic disorders.

Hybrid Vigor

The improved biological or growth characteristics resulting from crossbreeding.

Mutation

A change in the DNA sequence of an organism.

Visible Spectrum

The range of electromagnetic wavelengths that the human eye can perceive.

Meiosis

A type of cell division that reduces the chromosome number by half and leads to the production of gametes.

Nucleotide

The basic building block of nucleic acids, consisting of a sugar, phosphate group, and a nitrogenous base.

Nucleic Acids

Biomolecules that store and transmit genetic information, including DNA and RNA.

Phenotype

Observable traits or characteristics of an organism resulting from the interaction of its genotype and environment.

Genotype

The genetic constitution of an individual organism.

Chromosome

A structure composed of DNA and protein that carries genetic information.

Genetic Information

The information encoded in the sequences of DNA that determines an organism's biological characteristics.

Protein Folding

The process by which a polypeptide chain acquires its functional three-dimensional structure.

Peptide Bond

A covalent bond that links amino acids together in a protein.

Biochemical Pathway

A series of chemical reactions in a cell, catalyzed by enzymes.

Oncogenes

Genes that have the potential to cause cancer when mutated or expressed at high levels.

Tumor Suppressor Genes

Genes that regulate cell growth and division, preventing excessive cell proliferation.

Cell Signaling

The process of communication that governs basic cellular activities and coordinates cell actions.

Transcription

The process of copying a segment of DNA into RNA.

Translation

The process of synthesizing proteins from mRNA.

RNA Processing

Modification of RNA before it is translated into a protein.

Gene Therapy

A technique that modifies a person's genes to treat or cure disease.

Allopolyploidy

The condition of having more than two paired homologous sets of chromosomes derived from different species.

Endosymbiotic Theory

The theory that explains the origin of mitochondria and chloroplasts as former free-living bacteria.

Substrate-Level Phosphorylation

The direct generation of ATP from the transaction of energy from a substrate in the metabolic process.

Oxidative Phosphorylation

The metabolic pathway where cells use oxygen and simple sugars to generate ATP.

Photosynthesis

The process by which green plants, algae, and some bacteria convert light energy into chemical energy.

Cellular Respiration

The process by which cells break down glucose and other molecules to produce ATP.

Biological Magnification

The increasing concentration of toxins in organisms at each successive level of the food chain.

Metabolism

The set of life-sustaining chemical reactions that allow organisms to grow and reproduce.

Lipid Bilayer

A two-layered arrangement of phospholipids that form the cell membrane.

Homeostasis

The tendency of biological systems to maintain stability while adjusting to conditions that are optimal for survival.

Intestinal Crypts

Invaginations in the epithelial lining of the intestines that contain stem cells for intestinal regeneration.

Microvilli

Microscopic cellular membrane protrusions that increase surface area for absorption.

Antigen-Antibody Interaction

The binding of an antibody to a specific antigen, leading to an immune response.

Trophic Levels

The hierarchical levels in an ecosystem, comprising primary producers, consumers, and decomposers.