Unit 4: Cell Communication and Regulation (11-12)

Cell division

The process by which a cell reproduces and gives rise to new cells.

Genetically identical daughter cells

The result of most cell divisions, where the two daughter cells have the same genetic material as the parent cell.

Mitotic phase

The phase of the cell cycle where cell division occurs, including the stages of mitosis and cytokinesis.

Interphase

The phase of the cell cycle where the cell grows and carries out its normal functions, preparing for cell division.

Eukaryotic cell cycle

The series of events that a eukaryotic cell goes through from its formation to its division into two daughter cells.

Molecular control system

The system that regulates the progression of the eukaryotic cell cycle, ensuring that each phase occurs at the right time and in the correct order.

Daughter cells

The two cells that result from the division of a parent cell.

Prokaryotic cell

A type of cell that lacks a nucleus and other membrane-bound organelles.

Unicellular eukaryote

A single-celled organism that has a nucleus and other membrane-bound organelles.

Multicellular eukaryote

An organism made up of multiple cells, where cell division enables development from a single cell.

Reproduction

The ability of organisms to produce more of their own kind, which is based on the reproduction of cells through cell division.

Cell mechanics

The processes and mechanisms involved in cell division.

DNA

The genetic material of a cell, which is replicated and distributed during cell division.

Genome

The complete set of genetic material in an organism.

Chromosomes

Structures composed of DNA and proteins that carry genes and are involved in the replication and distribution of DNA during cell division.

Chromatin

The complex of DNA and proteins that make up chromosomes.

Condensation

The process of chromosomes becoming more tightly packed during cell division.

Somatic cells

All body cells except reproductive cells, which contain a characteristic number of chromosomes for each eukaryotic species.

Reproductive cells

Cells involved in sexual reproduction, such as sperm and eggs, which undergo a special type of cell division called meiosis.

Mitosis

The division of the genetic material in the nucleus.

Cytokinesis

The division of the cytoplasm.

Somatic cells

Cells that make up the body, produced through mitosis and cytokinesis.

Gametes

Reproductive cells, such as sperm and eggs.

Chromosomes

Structures in the cell that contain DNA.

Chromatin fiber

The form of a chromosome when a cell is not dividing.

Sister chromatids

Joined copies of a duplicated chromosome.

Centromere

The region where sister chromatids are attached most closely.

Arms of the chromatid

The portions of a chromatid on either side of the centromere.

Chromosome duplication

The process of replicating a chromosome, including DNA replication.

Chromosome condensation

The process of chromosomes becoming densely coiled and folded.

Separation of sister chromatids

The step in cell division where sister chromatids separate and become individual chromosomes.

Chromosome distribution

The process of distributing chromosomes to new nuclei during cell division.

Cell Cycle

The series of events that take place in a cell leading to its division and duplication.

S Phase

The phase of the cell cycle in which DNA synthesis or replication occurs.

G1 Phase

The first gap phase of the cell cycle, during which the cell grows and carries out its normal functions.

G2 Phase

The second gap phase of the cell cycle, during which the cell continues to grow and prepares for cell division.

Mitosis

The process of cell division in which the nucleus of a cell is divided into two daughter nuclei, each with the same number of chromosomes as the parent cell.

Cytokinesis

The division of the cytoplasm of a cell following mitosis, resulting in the formation of two daughter cells.

Chromosomes

Thread-like structures located in the nucleus of a cell that contain genetic information.

Interphase

The longest phase of the cell cycle, during which the cell grows and carries out its normal functions, and DNA replication occurs.

Centrosomes

Structures in animal cells that organize the microtubules of the spindle during cell division.

Prophase

The first stage of mitosis, during which the chromatin fibers condense into discrete chromosomes and the mitotic spindle begins to form.

Prometaphase

The stage of mitosis following prophase, during which the nuclear envelope fragments, microtubules invade the nuclear area, and the chromosomes become even more condensed.

Kinetochore

A specialized protein structure that forms at the centromere of each chromatid during prometaphase and attaches to the microtubules of the spindle.

Chromatid

One of the two identical copies of a chromosome that are joined at the centromere.

DNA

Deoxyribonucleic acid, the molecule that carries genetic information in all living organisms.

Daughter chromosomes

The individual chromosomes that result from the separation of sister chromatids during anaphase of mitosis.

Metaphase plate

An imaginary plane that is equidistant between the two poles of the spindle during metaphase of mitosis, where the chromosomes align.

Spindle

A structure composed of microtubules that forms during cell division and helps separate the chromosomes.

Nucleolus forming

The process of the nucleolus reappearing in the daughter cells during telophase of mitosis.

Nuclear envelope forming

The process of the nuclear envelope reforming around the daughter nuclei during telophase of mitosis.

Cleavage furrow

A groove that forms in animal cells during cytokinesis, which eventually leads to the separation of the two daughter cells.

Centrosome

A subcellular region that functions to organize the microtubules of the cell, including the spindle.

Metaphase

The stage of mitosis where the chromosomes align at the metaphase plate.

Anaphase

The stage of mitosis where the sister chromatids separate and move towards opposite ends of the cell.

Telophase and Cytokinesis

The final stages of mitosis where the nuclear envelopes reform, the chromosomes become less condensed, and the cytoplasm divides to form two daughter cells.

Kinetochore microtubules

Microtubules that function in the poleward movement of chromosomes during cell division.

Motor proteins

Proteins that are involved in the movement of objects along microtubules.

Pac-man mechanism

A mechanism in which motor proteins on the kinetochores "walk" the chromosomes along microtubules, which depolymerize at their kinetochore ends after the motor proteins have passed.

Cleavage furrow

A shallow groove in the cell surface that appears during cytokinesis in animal cells.

Contractile ring

A ring of actin microfilaments associated with molecules of the protein myosin, which contracts during cytokinesis in animal cells.

Cell plate

A structure that forms during cytokinesis in plant cells, derived from vesicles from the Golgi apparatus, and eventually develops into a new cell wall.

Cytokinesis

The process of cell division that involves the separation of the cytoplasm and the formation of two daughter cells.

Microtubule depolymerization

The process of microtubules breaking down or disassembling.

Tubulin subunits

The building blocks of microtubules, which are added or released during microtubule assembly and disassembly.

Chromosome movement

The movement of chromosomes during cell division, facilitated by microtubules and motor proteins.

Vesicles

Small sacs or pouches that transport materials within a cell.

Cell plate

A structure that forms during cell division in plant cells and eventually becomes the cell wall between the two daughter cells.

Mitosis

The process of cell division in which a single cell divides into two identical daughter cells.

Cytokinesis

The final stage of cell division, in which the cytoplasm divides to form two separate daughter cells.

Binary fission

A type of cell division in prokaryotes (bacteria and archaea) where a cell grows and then divides into two cells.

Eukaryotes

Organisms whose cells have a nucleus and other membrane-bound organelles.

Prokaryotes

Organisms whose cells do not have a nucleus or other membrane-bound organelles.

Chromosome

A structure made of DNA and proteins that carries genetic information.

Origin of replication

A specific place on a chromosome where DNA replication begins.

Plasma membrane

The outer boundary of a cell that separates the cell from its environment.

Polymerization

The process of forming a polymer, a large molecule made up of repeating subunits.

Actin

A protein that plays a role in cell movement and shape changes.

Tubulin

A protein that makes up microtubules, which are involved in cell division and cell structure.

Evolution

The process of change in living organisms over time.

Nuclear envelope

The double membrane that surrounds the nucleus of a eukaryotic cell.

Genome

The complete set of genetic material in an organism.

Dinoflagellates

Unicellular eukaryotes that have two flagella and are often found in marine environments.

Diatoms

Unicellular eukaryotes that have a unique cell wall made of silica and are important primary producers in aquatic ecosystems.

Yeasts

Single-celled fungi that can reproduce asexually by budding.

Chromosome replication

The process of copying a chromosome to produce two identical copies.

Chromosome

A structure made of DNA and proteins that carries genetic information.

Chromatid

One of the two identical copies of a chromosome that are joined together by a centromere.

Cytokinesis

The division of the cytoplasm that occurs after nuclear division, resulting in the formation of two daughter cells.

Tubulin

A protein that forms microtubules, which are involved in various cellular processes including cell division.

Actin

A protein that forms microfilaments, which are involved in various cellular processes including cell division.

Binary fission

A type of cell division in bacteria where the cell divides into two equal daughter cells.

Kinetochore

A protein structure on the centromere of a chromosome that attaches to microtubules during cell division.

Cell cycle

The series of events that take place in a cell leading to its division and duplication of its DNA.

Cell cycle control system

A set of regulatory proteins and checkpoints that control the progression of the cell cycle.

Mitosis

The process of nuclear division in eukaryotic cells, resulting in the formation of two genetically identical daughter nuclei.

Cell Cycle

The series of events that take place in a cell leading to its division and duplication.

Checkpoint signals

Internal and external signals that can either pause or continue the cell cycle.

Cyclins

Proteins that fluctuate in concentration and are required for the activation of cyclin-dependent kinases (Cdks).

Cyclin-dependent kinases (Cdks)

Enzymes that activate or inactivate other proteins by phosphorylating them, and their activity depends on the concentration of cyclins.