Key Terms in Chromosomes and Cell Division

anaphase,

apoptosis,

asexual reproduction,

binary fission,

cancer,

cell cycle,

cell-cycle control system,

centriole,

centromere,

checkpoints,

chiasmata (sing. chiasma),

chromatid,

chromatin,

chromosome,

complementarity,

complementary base,

condensation,

crossing over,

cytokinesis,

daughter cell,

diploid,

discontinuous replication,

DNA helicase,

DNA polymerase,

DNA synthesis phase,

fertilization,

gamete,

G0,

Gap 1 (G1),

Gap 2 (G2),

genetic recombination,

gonad,

growth factors,

haploid,

hermaphrodite,

histone,

homologous pair (homologues),

interphase,

karyotype,

kinetochore,

lagging strand,

leading strand,

meiosis,

metaphase,

microtubules,

mitosis,

mitotic phase (M phase),

nondisjunction,

origin of replication,

parent cell,

placenta,

polar body,

primase,

prophase,

random assortment,

recombination,

replication,

replication fork,

reproductive cell,

synthesis phase (S phase),

sexual reproduction,

sister chromatids,

somatic cell,

spindle,

spindle fiber,

telomere,

telophase,

X and Y chromosomes,

ABOUT THE CHAPTER OPENING PHOTO

Sibling similarities—such as those seen among the Jackson brothers (shown here performing in 1973)—illustrate the phenotypic consequences of genetic similarity; but the subtle differences also reveal variability among offspring in sexually reproducing species. The phenotypic variation stems from a variety of sources, including crossing over, the shuffling and reassortment of homologues during meiosis, and the contributions from two parents.

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