Biology Exam #2

Front 1

reproduction of cells

Back 1

cell division

Front 2

the life of a cell from the time it is first formed from a dividing parent cell until its own division into two cells

Back 2

cell cycle

Front 3

a cell's endowment of DNA, its genetic information

Back 3

genome

Front 4

packaged DNA

Back 4

chromosomes

Front 5

all body cells except the reproductive cells

Back 5

somatic cells

Front 6

reproductive cells (sperm and eggs)

Back 6

gametes

Front 7

a complex of DNA and associated protein molecules

Back 7

chromatin

Front 8

two chromatids, each containing an identical DNA molecule, that are attached to each other initially

Back 8

sister chromatids

Front 9

a specialized region where the two chromatids are most closely attached

Back 9

centromere

Front 10

the division of the nucleus, resulting in two, identical daughter cells

Back 10

mitosis

Front 11

cell division that results in 4, nonidentical daughter cells

Back 11

meiosis

Front 12

the phase which included both mitosis and cytokinesis, and is usually the shortest part of the cell cycle

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mitotic (M) phase

Front 13

the stage in which the cell grow and copies its chromosomes in preparation for cell division

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interphase

Front 14

the phase in which chromosomes are duplicated

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S phase

Front 15

a structure consisting of fibers made of microtubules and associated protiens

Back 15

mitotic spindle

Front 16

a subcellular region containing material that functions throughout the cell cycle to organize the cell's microtubules

Back 16

centrosome

Front 17

a radial array of short microtubules, extends from each centrosome

Back 17

aster

Front 18

a structure of proteins associated with specific sections of chromosomal DNA at the centromere

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kinetochore

Front 19

the imaginary plane midway between the spindle's two poles where the centromeres of all the duplicated chromosomes line up

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metaphase plate

Front 20

a shallow groove in the cell surface near the old metaphase plate

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cleavage furrow

Front 21

produced by vesicles derived from the Golgi apparatus move along microtubules to the middle of the cell, where they coalesce

Back 21

cell wall

Front 22

a type of cell division that involves asexual reproduction of single-celled eukaryotes

Back 22

binary fission

Front 23

a specific place on the chromosome where the chromosome begins to replicate

Back 23

origin of replication

Front 24

a cyclically operating set of molecules in the cell that both triggers and coordinates key events in the cell cycle

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cell cycle control system

Front 25

a control point where stop and go-ahead signals can regulate the cell cycle

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checkpoint

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a nondividing state

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G-zero phase

Front 27

enzymes that activate or inactivate other proteins by phosphorylating them

Back 27

protein kinases

Front 28

a protein that gets its name from its cyclically fluctuating concentration in the cell

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cyclin

Front 29

kinases that must be attached to cyclin to be active

Back 29

cyclin-dependent kinases (Cdks)

Front 30

the complex that triggers the cell's passage past the G2 checkpoint into M phase

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maturation-promoting factor/ M-phase promoting factor/ MPF

Front 31

a protein released by certain cells that stimulates other cells to divide

Back 31

growth factor

Front 32

a phenomenon in which crowded cell stop dividing

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density-dependent inhibition

Front 33

a phenomenon in which cells must be attached to a substratum, such as the inside of a culture jar or the extracellular matrix of tissue, to divide

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anchorage dependence

Front 34

the process that converts a normal cell to a cancer cell

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transformation

Front 35

a lump in which the abnormal cells remain at the original cell

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benign tumor

Front 36

a lump that becomes invasive enough to impair the functions of one or more organs

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malignant tumor

Front 37

the spread of cancer cells to locations distant from their original site

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metastasis

Front 38

the transmission of traits from one generation to the next

Back 38

heredity

Front 39

hereditary units

Back 39

genes

Front 40

reproductive cells in animals and plants

Back 40

gametes

Front 41

a single individual is the sole parent and passes copies of all its genes to its offspring

Back 41

asexual reproduction

Front 42

two parents give rise to offspring that have unique combinations of genes inherited from the two parents

Back 42

sexual reproduction

Front 43

the generation-to-generation sequence of stages in the reproductive history of an organism, from conception to production of its own offspring

Back 43

life cycle

Front 44

any cell other than those involved in gamete formation

Back 44

somatic cell

Front 45

an ordered display of chromosomes arranges in pairs, starting with the longest chromosomes

Back 45

karyotype

Front 46

the two chromosomes composing a pair that have the same length, centromere position, and staining pattern

Back 46

homologous chromosomes

Front 47

the X and Y chromosomes

Back 47

sex chromosomes

Front 48

chromosomes other than the sex chromosomes

Back 48

autosomes

Front 49

any cell with two chromosome sets

Back 49

diploid cell

Front 50

any cell with a single chromosome set

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haploid cell

Front 51

the union of gemetes, culminating in fusion of their nuclei

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fertilization

Front 52

the result of a fertilized egg

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zygote

Front 53

a type of life cycle that included both diploid and haploid stages that are multicellular

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alternation of generations

Front 54

the multicellular diploid stage in alternation of generations

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sporophyte

Front 55

Meiosis in a sporophyte produces haploid cells called:

Back 55

spores

Front 56

mitotic division generating a multicellular haploid stage in alternation of generations

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gametophyte

Front 57

stage that produces a diploid cell with replicated chromosomes

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meiosis 1

Front 58

stage that produces haploid cells with unreplicated chromosomes

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meiosis 2

Front 59

the process in which replicated homologs pair up and become physically connected along their lengths by a zipper-like protein structure

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synapsis

Front 60

genetic rearrangement between nonsister chromatids

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crossing over

Front 61

X-shaped region where nonsister chromatids remain connected while being pulled slightly apart

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chiasma

Front 62

individual chromosomes that carry genes derived from two different parents

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recombinant chromosomes

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a heritable feature that varies among individuals

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character

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varieties that, over many generations of self-pollination, produce on the same variety as the parent plant

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true-breeding

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the mating of two true-breeding varieties

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hybridization

Front 66

the true-breeding parents in a hybridization cross

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P generation

Front 67

the hybrid offspring of the P generation

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F1 generation

Front 68

the offspring resulting in F1 hybrids that self-pollinate

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F2 generation

Front 69

the two alleles for a heritable character segregate during gamete formation and end up in different gametes

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law of segregation

Front 70

a diagrammatic device for predicting the allele composition of offspring from a cross between individuals of known genetic makeup

Back 70

Punnett square

Front 71

an organism that has a pair of identical alleles for a character

Back 71

homozygous

Front 72

an organism that has two different alleles for a gene

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heterozygous

Front 73

an organism's appearance or observable traits

Back 73

phenotype

Front 74

an organism's genetic makeup

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genotype

Front 75

breeding an organism of unknown genotype with a recessive homozygote

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testcross

Front 76

heterozygous for one character

Back 76

monohybrid

Front 77

individuals heterozygous for two characters

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dihybrid

Front 78

each pair of alleles segregates independently of each other pair of alleles during gamete formation

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law of independent assortment

Front 79

phenomenon where the F1 offspring always looked like one of the two parental varieties because one allele in a pair shows ___________ over the other

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complete dominance

Front 80

phenomenon where neither allele is completely dominant, and the F1 hybrids have a phenotype somewhere between those of the two parental varieties

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incomplete dominance

Front 81

phenomenon in which the two alleles both affect the phenotype in separate, distinguishable ways

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codominance

Front 82

when one gene has multiple phenotypic effects

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pleiotropy

Front 83

a gene at one locus alters the phenotypic expression of a gene at a second locus

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epistasis

Front 84

characters that vary in the population along a continuum (in gradations)

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quantitative characters

Front 85

an additive effect of two or more genes on a single phenotypic character

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polygenic inheritance

Front 86

phenotypic range for a genotype

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norm of reaction

Front 87

a family tree describing the certain traits of parents and children across generations

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pedigree

Front 88

heterozygotes that can transmit the recessive allele to their offspring

Back 88

carriers

Front 89

technique of extracting amniotic fluid to perform genetic tests

Back 89

amniocentesis

Front 90

technique of extracting a sample of tissue in the placenta to perform genetic tests

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chorionic villus sampling (CVS)

Front 91

the theory that Mendelian genes have specific loci along chromosomes, and it is the chromosomes that undergo segregation and independent assortment

Back 91

chromosome theory of inheritance

Front 92

the phenotype for a character most commonly observed in natural populations

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wild type

Front 93

a gene located on either sex chromosome

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sex-linked gene

Front 94

disease in males characterized by a progressive weakening of the muscles and lack of coordination

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Duchenne muscular dystrophy

Front 95

a sex-linked recessive disorder defined by the absence of one or more of the proteins required for blood clotting

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hemophilia

Front 96

genes located on the same chromosome that tend to be inherited together in genetic crosses

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linked genes

Front 97

offspring that inherit a phenotype that matches one of the parental phenotypes

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parental types

Front 98

offspring with a phenotype combination unlike either parent

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recombinant types (recombinants)

Front 99

genetic map based on recombination frequencies

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linkage map

Front 100

the distance between genes

Back 100

map units (centimorgans)

Front 101

when the members of a pair of homologous chromosomes do not move apart properly during meiosis 1 or sister chromatids fails to separate during meiosis 2

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nondisjunction

Front 102

condition in which a zygote has an abnormal number of a chromosome

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aneuploidy

Front 103

an aneuploidic zygote with 2n-1 number of chromosomes

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monosomic

Front 104

an aneuploidic zygote with 2n+1 number of chromosomes

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trisomic

Front 105

condition in which an organism has more than two complete chromosome sets in all somatic cells

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polyploidy

Front 106

when a chromosomal fragment is lost

Back 106

deletion

Front 107

when a chromosomal fragment reattaches to the original chromosome but in the reverse orientation

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inversion

Front 108

when a fragment from one chromosome joins a different nonhomlogous chromosome

Back 108

translocation

Front 109

aneuploidy condition resulting from an extra chromosome 21, often called trisomy 21

Back 109

Down syndrome