Biology 210-1, Chapters 1 And 2

Front 1

Northern Blot

Back 1

Protocol for extracting mRNA, running through a gel, blotting onto a membrane, and probing with a cloned gene

Front 2

Southern Blot

Back 2

Protocol for extracting DNA, cutting with restriction enzymes, running on a gel, blotting onto a membrane, and probing with ssDNA

Front 3

Western blot

Back 3

Protocol for extracting protein, running on a gel, blotting onto a membrane, and probing with antibodies that are marked

Front 4

restriction enzyme

Back 4

an enzyme that cuts DNA at specific target sequences of four or more bases

Front 5

haploid

Back 5

having only a single set of genes in each cell

Front 6

diploid

Back 6

having two sets of genes in each cell, one set coming from each parent through a gamete

Front 7

eukaryote

Back 7

organisms made up of one or more cells with nuclear membrane and cellular compartments

Front 8

prokaryote

Back 8

single-celled organisms that have no nuclear membrane and lack intracellular compartments

Front 9

virus

Back 9

nonliving particles that lack all metabolic machinery; replicates by hijacking host cell reproduction machinery

Front 10

probing

Back 10

most popular method used for detecting specific macromolecules in a mixture; probes are designed to make use of the specificity of intermolecular binding and bind to only the sought-after macromolecule

Front 11

phenotype

Back 11

the physical manifestation of a trait in an organism's morphology or physiology

Front 12

model organisms

Back 12

organisms whose genetic mechanisms are common either to all species or to a large group of related organisms

Front 13

genotype

Back 13

the genetic constitution of an organism

Front 14

developmental noise

Back 14

random events in development lead to variation in phenotype; within a given genotype and environment, there is a range of possible outcomes for each developmental step

Front 15

crosses

Back 15

controlled matings

Front 16

genome

Back 16

an organism's unique and complete set of genetic information

Front 17

chromosomes

Back 17

units of nuclear DNA

Front 18

homologous chromosomes

Back 18

two members of a chromosome pair, also called homologs

Front 19

gene pair

Back 19

in diploids, since there are two of each chromosome, each gene appears as a gene pair

Front 20

nucleosomes

Back 20

a molecule found in DNA packaging, consists of eight smaller histone complexes

Front 21

chromatin

Back 21

the DNA, plus the associated nucleosomes; chromatin is what makes up chromosomes

Front 22

centromere

Back 22

a part of a chromosome that is visible as a constriction; flanked by densely packed chromatin

Front 23

heterochromatin

Back 23

dense chromatin

Front 24

euchromatin

Back 24

less dense chromatin

Front 25

nucleolar organizer

Back 25

a unique region of a chromosome that contains multiple repeats of genes encoding ribosomal RNA

Front 26

nucleolus

Back 26

a spherical body containing ribosomal RNA

Front 27

telomeres

Back 27

the tips of the chromosomes

Front 28

chromosomal bands

Back 28

transverse bands that appear on chromosomes after staining

Front 29

introns

Back 29

noncoding regions of the DNA that interrupt the coding segments of the gene

Front 30

pure lines

Back 30

all offspring produced by matings within the members of the line are phenotypically identical

Front 31

Mendel's First Law (law of equal segregation)

Back 31

the members of a gene pair separate equally into the eggs and sperm; a single gamete contains only one member of the gene pair, and gametes fuse randomly at fertilization

Front 32

zygote

Back 32

a fertilized egg (2n), develops into a progeny organism

Front 33

homozygote

Back 33

an organism with a pair of identical alleles

Front 34

heterozygote

Back 34

an organism in which the alleles of the pair differ

Front 35

monohybrid cross

Back 35

Y/y x Y/y

Front 36

mitosis

Back 36

the method by which somatic cells divide to increase their number

Front 37

meiocytes

Back 37

specialized diploid cells that are set aside to divide to produce sex cells

Front 38

meiosis

Back 38

the two sequential cell divisions that results in the formation of 4 gametic cells (1n) from a diploid cell (2n)

Front 39

dyad

Back 39

replicated sister chromosomes (together)

Front 40

bivalent

Back 40

the unit comprising the pair of synapsed dyads

Front 41

tetrad

Back 41

the four chromatids that make up a bivalent

Front 42

ascus

Back 42

a membranous sac that contains the meotiotic products of haploid meiosis

Front 43

null alleles

Back 43

alleles that code for proteins that completely lack function (they literally just sit in the cell, doing nothing)

Front 44

leaky mutations

Back 44

mutations that produce new proteins that still exhibit some wild-type functions

Front 45

haplosufficient

Back 45

a situation where one copy of the gene provides enough gene product (i.e. protein) to carry out the normal transactions of the cell

Front 46

haploinsufficient

Back 46

situations where a null mutant allele will be dominant and the cell won't produce enough product for normal function

Front 47

kinetochore

Back 47

the site for attachment of the centromere to spindle-fiber microtubules

Front 48

forward genetics

Back 48

gene discovery by single-gene inheritance; find mutants first, then ID time/place of action of genes involved

Front 49

reverse genetics

Back 49

analyze a set of genes that you think encode a biological property, then induce mutations until the phenotype changes and then you know you have the correct gene

Front 50

testcross

Back 50

cross an individual of unknown heterozygosity (A/A or A/a) with a fully recessive parent

Front 51

dioecious

Back 51

species of plants that show animal-like sexual dimorphisms

Front 52

psuedoautosomal regions 1 and 2

Back 52

two short homologous regions at each end of the X and Y chromosomes; one or both of these regions undergoes crossing over in meiosis

Front 53

propositus

Back 53

the individual who first comes to the attention of a geneticist in a pedigree analysis

Front 54

polymorphism (morphs)

Back 54

the coexistence of two or more common phenotypes of a character