Cell Division, Proliferation, Cancer, and Reproduction Lecture Review

Flashcards covering key vocabulary related to cell division, proliferation, genetics, cancer, and sexual reproduction based on the provided lecture notes.

Cell division

The process by which multicellular organisms grow, maintain, replace, and/or repair cells and tissues, also known as cellular reproduction.

Genome

The complete complement of DNA within an organism.

Chromatin

In eukaryotic cells, chromosomal DNA wound around proteins.

Karyotype

A visual arrangement of homologous chromosomes, typically organized from longest to shortest.

Homologous chromosomes

Pairs of chromosomes that are matched in a karyotype, containing genes for the same traits.

Locus (plural: loci)

The specific location of a gene on a chromosome.

Allele

One of a pair of genes inherited from each parent, which can be identical or vary to produce different characteristics.

Prokaryotic cells

Cells that reproduce asexually through binary fission and have a single circular piece of double-stranded DNA as their genome.

Binary fission

The asexual reproduction process in prokaryotes involving copying the genome and splitting the cell into two identical daughter cells.

Origin of replication

The point near the attachment site where DNA replication always begins in prokaryotes.

Bi-directional replication

The process of DNA replication moving away from the attachment site in prokaryotes.

Cleavage furrow (prokaryotic)

A structure that forms in the middle of a prokaryotic cell to divide cytoplasmic contents and the cell membrane during binary fission.

Septum (prokaryotic)

A structure formed from the periphery towards the center to divide the cell wall during prokaryotic cell division.

Cell proliferation

A process of tissue growth necessary for normal tissue development, maintenance, and reproduction, accomplished through mitosis and meiosis in eukaryotic cells.

Mitosis

A process of cell proliferation for growth and repair in somatic cells, where one cell produces two genetically identical daughter cells.

Meiosis

A process of cell proliferation for sexual reproduction in gametic cells, where one diploid cell produces four haploid daughter cells.

Somatic cells

Body cells (e.g., muscle or skin cells) that undergo mitosis for growth and repair.

Gametic cells

Reproductive cells that undergo meiosis for sexual reproduction.

Cell cycle

An ordered sequence of events in the 'lifetime' of a cell, consisting of Interphase and the Mitotic phase.

Interphase

The phase representing 90% of a cell's lifetime, during which normal cell functions occur, DNA gets replicated, and includes G1, S, and G2 stages.

Mitotic phase

The phase representing 10% of a cell's lifetime, involving active cell division where one cell becomes two cells.

G1 phase (Interphase)

A stage in interphase involving cell growth and protein synthesis.

S phase (Interphase)

A stage in interphase involving DNA replication and replication of the centrosome.

G2 phase (Interphase)

A stage in interphase involving further growth and protein synthesis.

Nuclear division

The process during mitosis where duplicated chromosomes are segregated and distributed into daughter nuclei.

Cytokinesis

The final stage of cell division following mitosis or meiosis where the cytoplasm splits into two daughter cells, including all essential cellular organelles.

Sister chromatids

Two identical copies of a chromosome formed during DNA replication, held together by a centromere.

Centromere

The constricted region that holds sister chromatids together.

Mitotic Spindle

A structure made of microtubules that helps separate chromosomes during cell division.

Centrosome

An organelle that contains centrioles and organizes the mitotic spindle.

Centrioles

Barrel-shaped organelles within the centrosome involved in spindle formation.

Prophase (Mitosis)

The first phase of mitosis where the nuclear envelope breaks, centrosomes move to opposite poles, and microtubules form mitotic spindles.

Prometaphase (Mitosis)

The phase during mitosis when chromosomes become condensed and visually discrete.

Metaphase (Mitosis)

The phase during mitosis when all chromosomes are aligned at the metaphase plate.

Anaphase (Mitosis)

The phase during mitosis when sister chromatids split, and the cell becomes visibly elongated.

Telophase (Mitosis)

The final phase of mitosis when chromosomes reach opposite poles and begin to decondense.

Contractile microfilaments (in animal cytokinesis)

A ring of actin and myosin proteins that constricts the cell, achieving cytokinesis in animal cells.

Cell plate (in plant cytokinesis)

A new cell wall formed by Golgi vesicles between two daughter cells in plant cells during cytokinesis, which later becomes a primary cell wall.

Cleavage furrow (eukaryotic)

An inward pinching of the plasma membrane created by the shrinking contractile ring at the cell's equator during cytokinesis.

Contractile ring (cytokinesis)

A ring of actin and myosin fibers that forms around the cell's equator and contracts to pinch the plasma membrane inward during cytokinesis.

G0 phase

An alternate, non-dividing phase that cells enter when they are not actively preparing to divide, which can be temporary or permanent.

Cell Cycle Control

Mechanisms including checkpoints during the cell cycle designed to prevent errors in mitosis and ensure daughter cells are identical to parent cells.

Genetic mutations

Errors in DNA replication or chromosome distribution that lead to changes in genetic sequence and can be inherited by offspring cells.

Cancer

A general term for diseases characterized by uncontrolled cell growth, division, and proliferation, which can lead to tumor formation and invasion of normal tissues.

Tumor

A mass of cells resulting from uncontrolled cell growth and proliferation.

Metastasize

The process by which tumor cells invade normal tissues or organs and spread to other parts of the body.

Proto-oncogenes

Genes that code for cell-cycle regulators for proper cell division; when over-active, they become oncogenes.

Oncogenes

Over-active proto-oncogenes that disrupt normal cell regulation, overstimulate cell division, and cause cells to become cancerous.

DNA repair

A proofreading and correction mechanism that occurs during and after DNA replication, functioning as part of cell cycle control to prevent accumulated errors leading to cancer.

Benign tumor

A noncancerous tumor that typically has no effect on surrounding tissue and does not spread.

Malignant tumor

A cancerous tumor that invades surrounding tissue.

Metastatic tumor

A cancerous tumor formed when individual cells break away from a primary tumor and start a new tumor elsewhere in the body.

Leukemias

Cancers affecting white blood cells and blood-forming tissues like bone marrow, characterized by excessive production of abnormal white blood cells.

Lymphomas

Cancers affecting lymphocytes (white blood cells) of the immune system, occurring when abnormal white blood cells multiply and overwhelm the lymphatic system.

Carcinomas

Cancers that start in epithelial tissues such as skin, lungs, breasts, and pancreas, accounting for 80-90% of all cancer cases.

Sarcomas

Malignant tumors that grow in connective tissues such as bone, cartilage, fat, muscle, and tendons.

Osteosarcoma

A type of sarcoma, specifically a bone tumor that usually occurs in young adults.

Chondrosarcoma

A type of sarcoma that affects cartilage.

Chemotherapy

Cancer treatment using one or more anti-cancer drugs (chemotherapeutic agents) to shrink or kill cancer cells.

Radiation therapy

Cancer treatment using high-energy rays (ionizing radiation) to damage cancer cells' DNA, killing them or slowing their growth.

Gene therapy (cancer treatment)

Cancer treatment involving engineering new molecules that specifically target cancer cells and induce apoptotic cell death.

Immunotherapy (cancer treatment)

Cancer treatment that works with the body’s immune system to help it fight cancer cells or control side effects from other treatments.

Hormone therapy

Cancer treatment that blocks cancer cells from getting the hormones they need to grow.

Stem cell transplant (bone marrow transplant)

A treatment to replace bone marrow cells lost due to high doses of chemotherapy or radiation therapy, commonly used for blood cancers and lymphomas.

Alkylation

A chemotherapy mechanism applying therapeutic agents that cause DNA damage (e.g., DNA cross-links and strand breaks) to stop cancer cells from reproducing, leading to apoptosis or cell necrosis.

Antimetabolism

A chemotherapy mechanism using chemical drugs to interfere with the cell cycle by mimicking or blocking essential building blocks for DNA and RNA synthesis, preventing cancer cell division.

Apoptosis

Programmed cell death, a potential outcome of certain cancer treatments on cancer cells.

Cell necrosis

Cell death involving swelling of cell organelles and rupture of the plasma membrane, a potential outcome of certain cancer treatments on cancer cells.

External radiotherapy

Radiation therapy delivered from outside the body, used to treat many types of tumors in areas like the head, neck, skin, and lung.

Brachytherapy

A type of radiation therapy where a small solid radioactive implant is placed in or near the cancer inside the body.

CAR T-cell therapy (Chimeric Antigen Receptor T-cell therapy)

A type of immunotherapy that modifies the genetic pathways of particular immune cells to strengthen the immune system against cancer or to weaken cancer cells.

Cyclin Dependent Kinases (CDKs)

A family of proteins involved in cell cycle regulation, often overexpressed in cancer cells, positively regulating cell division.

CDK Inhibitors

Substances that inhibit the function of Cyclin Dependent Kinases (CDKs), used in cancer treatment to prevent cancer cell growth or division.

Tumor suppressors

Proteins that inspect newly replicated DNA and negatively regulate cell division by halting the cell cycle if errors are detected, preventing abnormal cell growth.

p53

A tumor suppressor protein activated by cellular stress signals (e.g., DNA damage) that induces cell cycle arrest, DNA repair, senescence, or apoptosis if cellular damage is irreparable.

Tumor metastasis

The process by which cancer cells spread from their original location (primary tumor) to other parts of the body, forming new tumors (metastatic tumors).

Primary tumor

The original tumor from which cancer cells spread.

Metastatic tumors

New tumors formed in other parts of the body by cancer cells that have spread from a primary tumor.

Invasion (metastasis)

A stage of metastasis where tumor cells break through the basement membrane and extracellular matrix to pass into lymphatic or vascular circulation.

Intravasation

A stage of metastasis where tumor cells enter the vascular circulation.

Extravasation

A stage of metastasis where tumor cells invade the vascular basement membrane and extracellular matrix upon exiting the circulatory system.

Sexual reproduction

A process that leads to offspring genetically different from one another and either parent, involving the production of haploid gametes through meiosis.

Gametes

Sex cells (e.g., sperm and egg cells) that are haploid (n), containing only one copy of each chromosome.

Haploid (1n)

Refers to cells (like gametes) that have a single set of chromosomes.

Diploid (2n)

Refers to cells that contain two sets of chromosomes, one inherited from each parent.

Fertilization

The joining of two haploid gametes (an egg and a sperm) to form a diploid cell.

Diploid-dominant life cycle

A life cycle (like in animals) where the multicellular organism is diploid throughout most of its life.

Haploid-dominant life cycle

A life cycle (like in fungi) where the organism contains haploid nuclei throughout most of its life, with a single diploid cell formed during sexual reproduction that immediately undergoes meiosis.

Alternating life cycle (plants)

A life cycle (like in plants) that alternates between a multicellular haploid organism and a multicellular diploid organism.

Meiosis I

The first round of meiosis where homologous chromosomes pair up and are then separated into two cells, each containing one set of duplicated chromosomes.

Meiosis II

The second round of meiosis where sister chromatids in each cell are separated, resulting in four haploid offspring cells.

Homologue

Each member of a homologous chromosome pair, one inherited from the mother and one from the father.

Crossover (Meiosis I)

The exchange of genetic material between non-sister chromatids of homologous chromosomes during Prophase I of meiosis, resulting in recombinant chromosomes.

Non-sister chromatids

Chromatids from homologous chromosomes (one from the maternal, one from the paternal chromosome) that exchange genetic material during crossover.

Recombinant chromosomes

Chromosomes that have a mixture of maternal and paternal gene sequences due to crossing over, increasing genetic variation.

Non-recombinant chromosomes

Chromosomes that are completely identical to the paternal or maternal chromosomes, without any crossing over.

Independent Assortment

The random arrangement and separation of homologous chromosome pairs during Metaphase I, leading to genetically different gametes.

Chromosome non-disjunction

The failure of homologous chromosomes or sister chromatids to separate properly during meiosis, leading to an abnormal number of chromosomes in daughter cells.

Duplication (chromosome)

A chromosomal abnormality involving the presence of an extra copy of a DNA segment, chromosomal region, or an entire chromosome.

Deletion (chromosome)

A chromosomal abnormality involving the loss of a chromosome fragment or segment.