Chapter 12-13 Test Vocab Flashcards
An ordered sequence of events in the life of a cell, from its origin in the division of a parent cell until its own division into two. The eukaryotic sequence is composed of interphase (including G1, S, and G2 subphases) and M phase (including mitosis and cytokinesis).
Cell Cycle
The genetic material of an organism or virus; the complete complement of an organism’s or virus’s genes along with its noncoding nucleic acid sequences.
Genome
A cellular structure carrying genetic material, found in the nucleus of eukaryotic cells. Each consists of one very long DNA molecule and associated proteins.
Chromosome
The complex of DNA and proteins that makes up eukaryotic chromosomes. When the cell is not dividing, it exists in its dispersed form, as a mass of very long, thin fibers that are not visible with a light microscope.
Chromatin
Any cell in a multicellular organism except a sperm or egg or their precursors.
Somatic Cell
A haploid reproductive cell, such as an egg or a sperm. They unite during sexual reproduction to produce a diploid zygote.
Gametes
A cell containing only one set of chromosomes (n).
Haploid
A cell containing two sets of chromosomes (2n), one set inherited from each parent.
Diploid
Two copies of a duplicated chromosome attached to each other by proteins at the centromere and, sometimes, along the arms. While joined, they make up one chromosome. They are eventually separated during mitosis or meiosis II.
Sister Chromatids
In a duplicated chromosome, the region on each sister chromatid where they are most closely attached to each other by proteins that bind to specific DNA sequences; this close attachment causes a constriction in the condensed chromosome. (An uncondensed, unduplicated chromosome has one of these, identified by its DNA sequence.)
Centromere
A process of nuclear division in eukaryotic cells conventionally divided into five stages: prophase, prometaphase, metaphase, anaphase, and telophase. It conserves chromosome number by allocating replicated chromosomes equally to each of the daughter nuclei.
Mitosis
The division of the cytoplasm to form two separate daughter cells immediately after mitosis, meiosis I, or meiosis II.
Cytokinesis
The phase of the cell cycle that includes mitosis and cytokinesis.
Mitotic (M) Phase
An assemblage of microtubules and associated proteins that is involved in the movement of chromosomes during mitosis.
Mitotic Spindle
A structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center and is important during cell division. It has two centrioles.
Centrosome
Hollow rods composed of tubulin proteins that make up part of the cytoskeleton in all eukaryotic cells and are found in cilia and flagella.
Microtubules
A radial array of short microtubules that extends from each centrosome toward the plasma membrane in an animal cell undergoing mitosis.
Aster
A structure of proteins attached to the centromere that links each sister chromatid to the mitotic spindle.
Kinetochore
An imaginary structure located at a plane midway between the two poles of a cell in metaphase on which the centromeres of all the duplicated chromosomes are located.
Metaphase Plate
The process of cytokinesis in animal cells, characterized by pinching of the plasma membrane.
Cleavage
The first sign of cleavage in an animal cell; a shallow groove around the cell in the cell surface near the old metaphase plate.
Cleavage Furrow
A membrane-bounded, flattened sac located at the midline of a dividing plant cell, inside which the new cell wall forms during cytokinesis.
Cell Plate
A method of asexual reproduction by “division in half.” In prokaryotes, it does not involve mitosis, but in single-called eukaryotes that undergo it, mitosis is part of the process.
Binary Fission
A cyclically operating set of molecules in the eukaryotic cell that both triggers and coordinates key events in the cell cycle.
Cell Cycle Control System
A control point in the cell cycle where stop and go-ahead signals can regulate the cycle.
Checkpoint
A nondividing state occupied by cells that have left the cell cycle, sometimes reversibly.
G0 Phase
A cellular protein that occurs in a cyclically fluctuating concentration and that plays an important role in regulating the cell cycle.
Cyclin
An enzyme that transfers phosphate groups from ATP to a protein, thus phosphorylating the protein.
Protein Kinase
A protein kinase that is active only when attached to a particular cyclin.
Cyclin-Dependent Kinase (Cdk)
A protein that must be present in the extracellular environment for the growth and normal development of certain types of cells.
Growth Factors
The phenomenon observed in normal animal cells that causes them to stop dividing when they come into contact with one another.
Density-Dependent Inhibition
The requirement that a cell must be attached to a substratum in order to initiate cell division.
Anchorage Dependence
A mass of abnormal cells with specific genetic and cellular changes such that the cells are not capable of surviving at a new site and generally remain at the site of the tumor’s origin.
Benign Tumor
A cancerous tumor containing cells that have significant genetic and cellular changes and are capable of invading and surviving in new sites. They can seriously impair the function of one or more organs.
Malignant Tumor
The spread of cancer cells to locations distant from their original site.
Metastasis
Discrete units of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA in some viruses).
Genes
Haploid reproductive cells, such as eggs or sperms. They unite during sexual reproduction to produce a diploid zygote.
Gametes
A specific place along the length of a chromosome where a given gene is located.
Locus
A group of genetically identical individuals.
Clone
A display of the chromosome pairs of a cell arranged by size and shape.
Karyotype
Chromosomes that are not directly involved in determining sex; they are not sex chromosomes.
Autosomes
Chromosomes responsible for determining the sex of an individual.
Sex Chromosomes
The union of haploid gametes to produce a diploid zygote.
Fertilization
The diploid cell produced by the union of haploid gametes during fertilization; a fertilized egg.
Zygote
A modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round of DNA replication. It results in cells with half the number of chromosome sets as the original cell.
Meiosis
The first division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original cell.
Meiosis I
The second division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original cell.
Meiosis II
The pairing and physical connection of duplicated homologous chromosomes during prophase I of meiosis.
Synapsis
A zipper-like protein structure that synapses homologous chromosomes.
Synaptonemal Complex
The x-shaped, microscopically visible region where crossing over has occurred earlier in prophase I between homologous nonsister chromatids. They become visible after synapsis ends, with the two homologs remaining associated due to sister chromatid cohesion.
Chiasma
The reciprocal exchange of genetic material between nonsister chromatids during prophase I of meiosis.
Crossing Over
A pair of chromosomes of the same length, centromere position, and staining pattern that possess genes for the same characteristics at corresponding loci. One is inherited from the organism’s father, the other from the mother.
Homologs
Each pair of homologs sorts their maternal and paternal chromosomes into daughter cells independently of every other pair.
Independent Assortment
A chromosome created when crossing over combines DNA from two parents into a single chromosome.
Recombinant Chromosome
