IB Bio D2: Cells: Cell and Nuclear Division;Gene Expression*;Water Potential

Theme: Continuity and Change ( *) = HL only

Actin

A globular protein that forms microfilaments and is crucial for muscle contraction and cell movement.

Anaphase

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

Animal Cell

A type of cell that is eukaryotic, contains membrane-bound organelles, and lacks a cell wall, typically found in multicellular organisms.

Anucleate Cell

A cell that lacks a nucleus, often found in certain types of mature red blood cells in mammals.

Benign*

A type of tumor that is non-cancerous, grows slowly, and typically does not spread to other parts of the body.

Bivalent

A structure formed during meiosis consisting of a pair of homologous chromosomes that are closely associated.

Cancer*

A disease characterized by uncontrolled cell division, which may form tumors and can spread to other parts of the body.

Cell Cycle*

The series of events that a cell goes through leading to its division and replication.

Cell Cycle Checkpoint*

Regulatory points in the cell cycle that ensure proper division and DNA integrity.

Cell Division

The process by which a single cell divides into two daughter cells.

Cell Growth*

The phase in the cell cycle where a cell increases in size, synthesizes proteins, and duplicates its organelles before division.

Cell Membrane

A biological membrane that separates and protects the cell's interior from the external environment, controlling substance movement.

Cell Proliferation

The process by which cells divide and increase in number.

Cell Replacement

The process of replacing damaged or dead cells in an organism.

Cell Wall

A rigid outer layer that provides structure and support to plant cells.

Chromatid

One half of a duplicated chromosome, visible during cell division.

Chromosome Number

The total number of chromosomes in a cell, determining its genetic makeup.

Condensation (of Chromosome)

The process of coiling and folding DNA to form compact chromosomes during cell division.

Crossing Over

The exchange of genetic material between homologous chromosomes during meiosis.

Cyclin

Proteins that regulate the cell cycle progression.

Cytokinesis

The process where the cytoplasm divides to form two separate daughter cells after mitosis.

Cytoplasm

The gel-like substance within a cell, containing organelles and the site for cellular processes.

Daughter Cell

A cell produced from the division of a parent cell.

Diploid

A cell or organism with two sets of chromosomes, one from each parent.

DNA Replication

The process of copying DNA to create two identical strands.

Down Syndrome

A genetic disorder caused by the presence of all or part of a third copy of chromosome 21, leading to developmental delays and physical characteristics.

Embryo

An early stage of development in multicellular organisms, following fertilization.

Eukaryotes

Organisms with cells that contain a nucleus and membrane

G1 Phase

The first phase of the cell cycle where cells grow and prepare for DNA replication.

G2 Phase*

The phase of the cell cycle where the cell prepares for mitosis.

Genetic Diversity

Variation in genetic traits within a population.

Haploid

A cell or organism with one complete set of chromosomes, typically found in gametes.

Histone

Proteins that help package DNA into chromatin.

Interphase*

The phase in the cell cycle during which a cell spends most of its life, preparing for division by growing and replicating its DNA.

Malignant*

A type of cancer cell that grows uncontrollably and can invade surrounding tissues and spread to other parts of the body.

Meiosis

A type of cell division that reduces the chromosome number by half, producing four genetically diverse gametes.

Meristem*

A region in plants where undifferentiated cells are actively dividing, contributing to growth and the formation of new tissues.

Metaphase

The stage of cell division in which chromosomes become aligned in the center of the cell, preparing for separation. This occurs during both mitosis and meiosis.

Metastasis*

The process by which cancer cells spread from the original tumor site to other parts of the body, often via the bloodstream or lymphatic system.

Microtubule Motors

Proteins that move along microtubules to transport cellular components and facilitate cell movement.

Microtubules

Cylindrical structures made of tubulin that provide structural support and facilitate intracellular movement.

Mitosis

A type of cell division that results in two genetically identical diploid daughter cells, used for growth and tissue repair.

Mitotic Index*

A ratio that compares the number of cells in mitosis to the total number of cells in a sample, used to evaluate cell proliferation.

Mutation*

A change in the DNA sequence of an organism, which can lead to alterations in gene function and may affect traits or disease susceptibility.

Myosin

A motor protein that interacts with actin filaments to enable muscle contraction and cellular movement.

Non-Disjunction

The failure of chromosome separation during meiosis or mitosis, leading to aneuploidy.

Nuclear Division

The process by which a cell divides its nucleus, resulting in either mitosis (producing two identical daughter nuclei) or meiosis (producing gametes with half the chromosome number).

Oncogene*

A gene that has the potential to cause cancer when mutated or overexpressed, often promoting uncontrolled cell division.

Oogenesis

The process of egg cell development in females, where primary oocytes undergo meiosis to produce mature ova.

Organism Growth*

The process of increasing in size and complexity, resulting from cell division, differentiation, and the accumulation of mass.

Parent Cell

A cell that divides to produce daughter cells during cell division, maintaining genetic information.

Plant Cell

A type of eukaryotic cell that makes up the tissues of plants, characterized by a rigid cell wall, chloroplasts for photosynthesis, and a central vacuole.

Primary Tumour*

A mass of cancer cells that originates from the uncontrolled division of a single cell in a particular tissue or organ.

Prophase

The first stage of mitosis, where chromatin condenses into visible chromosomes, the nuclear envelope breaks down, and spindle fibers begin to form.

Proto-Oncogene*

A normal gene that can become an oncogene due to mutations or increased expression. Proto-oncogenes play a critical role in cell growth and division.

Random Orientation

The process during meiosis where homologous chromosomes or sister chromatids are randomly aligned at the cell's equatorial plate, leading to a mix of maternal and paternal chromosomes in gametes.

Reductive Division

The type of cell division that reduces the chromosome number by half, occurring during meiosis. This process results in the formation of haploid gametes.

S Phase*

The phase in the cell cycle where DNA is replicated, resulting in two identical sets of chromosomes. This occurs between the G1 and G2 phases before cell division.

Secondary Tumour*

A tumor that develops away from the primary site of cancer, often as a result of cancer cells spreading through the bloodstream or lymphatic system.

Sexual Life Cycle

The series of stages in an organism's life that involve the alternation between haploid and diploid phases, including gamete formation through meiosis and fertilization.

Supercoiling

A process where DNA is twisted and compacted, enabling it to fit within the cell nucleus. Supercoiling is crucial for DNA packaging and regulation during replication and transcription.

Telophase

The final stage of mitosis and meiosis where the chromosomes arrive at opposite poles of the cell and begin to decondense, ultimately leading to the formation of two distinct nuclei.

Tissue Repair*

Healing and regrowth of tissues after injury, involving cell division.

Tumor Suppressor Gene*

A gene that regulates cell division and prevents excessive cell growth. Tumor suppressor genes can help prevent the formation of tumors by repairing damaged DNA or inducing apoptosis.

Tumour*

An abnormal mass of tissue that forms when cells divide uncontrollably, which can be benign or malignant.

Vesicle

A membrane-bound structure that transports materials within a cell or between cells.

Yeast Budding

Asexual reproduction in yeasts where a new organism develops from a bud on the parent.

Air Pollution*

The presence of harmful substances in the air that can have detrimental effects on human health and the environment.

Amino Acid*

Amino acids are organic compounds that serve as the building blocks of proteins, composed of an amino group, a carboxyl group, and a unique side chain.

Base Sequence*

The order of nucleotides in a DNA or RNA molecule that determines genetic information.

Cystine*

Amino acid formed from two cysteines linked by a disulfide bond, important for protein structure.

Differentiation*

The process by which a less specialized cell becomes a more specialized cell type, often involving changes in gene expression and function.

Deoxyribonucleic Acid (DNA)*

A double helix molecule that encodes genetic instructions vital for growth, development, and reproduction of living organisms.

Enhancer*

A short region of DNA that can increase the likelihood of transcription of a particular gene, often functioning at a distance from the gene itself.

Epigenetic*

related to changes in gene expression without altering the DNA sequence.

Epigenetic Tag*

Chemical modifications that regulate gene expression without altering the DNA sequence.

Gene Expression*

the process by which information from a gene is used to synthesize functional gene products, typically proteins.

Genome*

The complete set of genetic material, including all of its genes and non-coding sequences, contained in an organism's DNA.

Genotype*

The genetic constitution of an organism, determining specific traits and characteristics. It refers to the specific alleles inherited from parents.

Histone*

Proteins that help package DNA into nucleosomes, playing a critical role in gene regulation and chromatin structure.

Hormone*

A biochemical substance produced by glands that regulates various physiological processes in the body.

Lactose*

A sugar found in milk, lactose is a disaccharide composed of glucose and galactose. It is broken down by the enzyme lactase in the small intestine.

Liger*

A hybrid offspring of a male lion and a female tiger, known for its large size and strength.

Meiosis*

A type of cell division that reduces the chromosome number by half, resulting in four genetically diverse gametes. It consists of two successive divisions: meiosis I and meiosis II.

Methyl Tag*

A chemical modification to DNA involving the addition of a methyl group, which can regulate gene expression by altering chromatin structure.

Methylation*

The process by which methyl groups are added to the DNA molecule, often affecting gene expression without changing the DNA sequence.

Mitosis*

A type of cell division that results in two daughter cells, each with the same number of chromosomes as the parent cell, crucial for growth and tissue repair.

Monozygotic Twin*

A type of twin that develops from a single fertilized egg, resulting in genetically identical siblings.

mRNA*

A type of RNA that carries genetic information from DNA to the ribosome, where proteins are synthesized.

Multicellular*

Organism consisting of multiple cells that work together, as opposed to unicellular organisms.

Nuclease*

An enzyme that cleaves the chains of nucleotides in nucleic acids into smaller units.

Nucleosome*

A structural unit of a eukaryotic chromosome, consisting of a segment of DNA wrapped around a core of histone proteins. Nucleosomes help package DNA into a compact form, facilitating gene regulation and DNA stability.

Ovum*

A mature female gamete or egg cell involved in reproduction, which can be fertilized by a sperm cell to initiate embryonic development.

Phenotype*

The physical expression of genes in an organism, including observable traits such as appearance, development, and behavior.

Promoter*

A region of DNA that initiates transcription of a particular gene, binding RNA polymerase and transcription factors.

Protein*

A macromolecule made up of amino acids that perform various functions in living organisms, including catalyzing biochemical reactions and providing structural support.

Proteome*

The complete set of proteins that can be expressed by a genome, cell, or organism at a certain time.

Sperm*

The male reproductive cell, responsible for fertilizing the female gamete (ovum) during reproduction.

Tigon*

A hybrid cross between a male tiger and a female lion, known for its large size and strength.

Transcription*

The process by which genetic information encoded in DNA is copied into RNA. This is the first step in gene expression, leading to protein synthesis.