Unit 3

the stage in mitosis or meiosis during which chromosomes are moved to opposite poles of the spindle apparatus

a structure that serves as a microtubule-organizing center for the cell’s cytoskeleton and for the spindle apparatus during cell division; includes centrioles in animal cells and certain plants and fungi

1 of the 2 identical double-stranded DNAs that are connected at the centromere and compose a replicated chromosome

the complex of DNA and proteins (mainly histones) that compose eukaryotic chromosomes; can be highly compact or loosely coiled

gene-carrying structure consisting of a single long molecule of double-stranded DNA and associated proteins (histones); most prokaryotic cells contain a single, circular one; eukaryotic cells contain multiple noncircular ones located in the nucleus

division of cytoplasm to form 2 daughter cells; in eukaryotic cells, typically occurs immediately after division of the nucleus by mitosis or meiosis

one of several positively charged (basic) proteins associated with DNA in the chromatin of eukaryotic cells

the portion of the cell cycle between one M phase and the next; includes G1, S, and G2 phase

a protein complex that forms on a chromosome during M phase; forms at centromere and serves as site for microtubule attachment; contains motor proteins and microtubule-binding proteins that are involved in chromosome segregation during M phase

an imaginary plane (between the spindle poles) along which chromosomes line up during metaphase of mitosis or meiosis

in eukaryotic cells, the process of nuclear division that results in 2 daughter nuclei that are genetically identical to the parent nucleus; cytokinesis yields 2 daughter cells

a stage in mitosis or meiosis during which the nuclear envelope breaks down and microtubule attach to kinetochores

the first stage in mitosis or meiosis where chromosomes condense and the spindle apparatus forms; synapsis and crossing over occur during meiosis I

the paired, double-stranded DNA copies of a recently replicated chromosome; connected most tightly at the centromere and eventually separate during anaphase of mitosis or meiosis II

any type of cell in a multicellular organism except eggs, sperm, and their precursor cells

the final stage in mitosis or meiosis where daughter chromosomes (or homologous chromosomes in meiosis I) have moved to opposite poles and new nuclear envelopes begin to form around each set of chromosomes

a bead-like unit of eukaryotic chromatin, consisting of about 200 nucleotides of DNA wrapped twice around 8 histone proteins

a particular version of a gene

describes the opposite orientation of nucleic acid strands that are hydrogen-bonded to one another, with one strand runnin gin the 5’ —> 3’ direction and the other in the 3’ —> 5’ direction

a heterozygous individual carrying a normal allele and a recessive allele for an inherited trait; the individual does not display the phenotype of the recessive trait but can pass the recessive allele to offspring

two DNA copies are produced from one original DNA, which serves as a template; out of these two, one is entirely new DNA, and the other is made of old DNA strands

the synthesis of a new strand of a replicating DNA molecule as a series of short fragments that are subsequently joined together