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8
The Cellular Basis of Reproduction and
Inheritance
Chapter 8 Objectives
Opening Essay
Describe the life-cycle phases of a multicellular organism. Explain how asexual
reproduction can be used to save a plant species from extinction.
Connections Between Cell Division and Reproduction
8.1
8.2
8.3
Compare the parent-offspring relationship in asexual and sexual reproduction.
Explain why cell division is essential for eukaryotic and prokaryotic life.
Explain how daughter prokaryotic chromosomes are separated from each other during
binary fission.
The Eukaryotic Cell Cycle and Mitosis
8.3–8.4
8.5
8.6
8.7
8.8–8.9
8.10
8.11
Compare the structure of prokaryotic and eukaryotic chromosomes.
Describe the stages of the cell cycle. Identify when DNA is replicated, chromosomes are
sorted, and two new cells are formed.
List the phases of mitosis and describe the events characteristic of each phase. Recognize
the phases of mitosis from diagrams and micrographs.
Compare cytokinesis in animal and plant cells.
Explain how anchorage, cell density, and growth factors control cell division.
Explain how cancerous cells are different from healthy cells. Distinguish between benign
and malignant tumors and explain the strategies behind some common cancer treatments.
Describe the functions of mitosis.
Meiosis and Crossing Over
8.12
8.13
8.14
8.15
Explain how chromosomes are paired. Distinguish between autosomes and
sexchromosomes.
Distinguish between somatic cells and gametes and between diploid cells and haploid
cells.
List the phases of meiosis I and meiosis II and describe the events characteristic of each
phase. Recognize the phases of meiosis from diagrams and micrographs.
Describe the similarities and differences between mitosis and meiosis. Explain how the
result of meiosis differs from the result of mitosis.
8.16–8.18
Explain how independent orientation of chromosomes at metaphase I, random
fertilization, and crossing over during prophase I of meiosis contribute to genetic
variation in sexually reproducing organisms.
Alterations of Chromosome Number and Structure
8.19
8.20
8.21
8.22
8.23
8.24
Explain how and why karyotyping is performed.
Describe the causes and symptoms of Down syndrome.
Define nondisjunction, explain how it can occur, and describe what can result.
Describe the consequences of abnormal numbers of sex chromosomes.
Explain how new species form from errors in cell division.
Describe the main types of chromosomal changes. Explain why cancer is not usually
inherited.
Key Terms
anaphase
anchorage dependence
asexual reproduction
autosome
benign tumor
binary fission
carcinoma
cell cycle
cell cycle control system
cell division
cell plate
centromere
centrosome
chiasma (plural, chiasmata)
chromatin
chromosome
cleavage
cleavage furrow
crossing over
cytokinesis
deletion
density-dependentinhibition
diploid cell
Down syndrome
duplication
fertilization
gamete
genetic recombination
genome
growth factor
haploid cell
homologouschromosomes
interphase
inversion
karyotype
leukemia
life cycle
locus (plural, loci)
lymphoma
malignant tumor
meiosis
metastasis
mitotic phase (M phase)
mitotic spindle
mitosis
nondisjunction
prometaphase
prophase
sarcoma
sex chromosome
sexual reproduction
sister chromatid
somatic cell
telophase
tetrad
translocation
trisomy 21
tumor
zygote
Word Roots
a- 5 not or without (asexual reproduction: the creation of offspring by a single parent, without
theparticipation of sperm and egg)
ana- 5 up, throughout, again (anaphase: the fourth stage of mitosis, beginning when sister chromatids
separate from each other and ending when a complete set of daughter chromosomes arrives at each of the
two poles of the cell)
auto- 5 self; -soma 5 body (autosome: a chromosome not directly involved in determining the sex of an
organism)
bi- 5 two (binary fission: a means of asexual reproduction in which a parent organism, often a single cell,
divides into two individuals of about equal size)
centro- 5 the center; -mere 5 a part (centromere: the region of a duplicated chromosome where two sister
chromatids are joined and where spindle microtubules attach during mitosis and meiosis); -soma 5 body
(centrosome: a nonmembranous organelle that functions throughout the cell cycle to organize the cell’s
microtubules)
chiasm- 5 marked crosswise (chiasma [plural, chiasmata]: the X-shaped microscopically visible site
where crossing over has occurred between the chromatids of homologous chromosomes duringprophase I
of meiosis)
chroma- 5 colored (chromatin: DNA and the various associated proteins that form eukaryotic
chromosomes); -soma 5 body (chromosome: a threadlike, gene-carrying structure composed of
chromatin, found in the nucleus of eukaryotic cells)
cyto- 5 cell; -kinet 5 move (cytokinesis: the division of the cytoplasm to form two separate daughter cells)
di- 5 two (diploid cell: in an organism that reproduces sexually, a cell containing two homologous sets of
chromosomes, one from each parent)
fertil- 5 fruitful (fertilization: the union of the nucleus of a sperm cell with the nucleus of an egg cell,
producing a zygote)
gamet- 5 a wife or husband (gamete: a haploid egg or sperm cell)
gen- 5 produce (genome: a complete [haploid] set of an organism’s genes; an organism’s genetic
material)
haplo- 5 single (haploid cell: in the life cycle of an organism that reproduces sexually, a cell containing a
single set of chromosomes)
homo- 5 like (homologous chromosomes: the two chromosomes that make up a matched pair in a diploid
cell)
inter- 5 between (interphase: the period in the eukaryotic cell cycle when the cell is not actually dividing)
karyo- 5 nucleus (karyotype: a display of micrographs of the metaphase chromosomes of a cell)
mal- 5 bad or evil (malignant tumor: an abnormal tissue mass that can spread into neighboring tissue and
to other parts of the body)
meio- 5 less (meiosis: a form of cell division that yields daughter cells with half as many chromosomes as
the parent cell)
meta- 5 between (metaphase: the third mitotic stage, during which all the cell’s duplicated chromosomes
are aligned in the middle of the cell)
mito- 5 a thread (mitosis: the division of a single nucleus into two genetically identical daughter nuclei)
non- 5 not; dis- 5 separate (nondisjunction: an accident of meiosis or mitosis in which a pair
ofhomologous chromosomes or a pair of sister chromatids fail to move separate at anaphase)
pro- 5 before (prophase: the first mitotic stage, during which the chromatin condenses to form sister
chromatids)
soma- 5 body (somatic cell: any cell in a multicellular organism except a sperm or egg cell, or a cell that
develops into a sperm or egg)
telos- 5 an end (telophase: the final stage of mitosis, during which daughter nuclei form)
trans- 5 across (translocation: attachment of a chromosomal fragment to a nonhomologous chromosome)
tri- 5 three; soma- 5 body (trisomy: a chromosomal condition in which a particular cell has an extra copy
of one chromosome, instead of the normal two; the cell is said to be trisomic for that chromosome)