binary fission (i.e., splitting into two): cell division in prokaryotes
prokaryote (pro-, "before" + karyo, "kernel, nut" [i.e., nucleus]): organisms that don't have nuclei in their cells -- bacteria
eukaryote (eu-, "good, true" + karyo, "kernel, nut" [i.e., nucleus]): organisms with nuclei in their cells
mitosis (mitos-, "thread" + -osis, "a process"): the division of the nucleus of the eukaryotic cell
cytokinesis (cyto-, "cell, cytoplasm" + -kinesis, "movement"): the division of the cytoplasm in eukaryotic cell division
chromosome (chromo-, "color" + -some, "body"): the structures that contain a cell's genetic information
genome: a complete set of an organism's genes
chromatin (chromat-, "color" + -in, suffix for a molecule): the diffuse form the chromosomes take on during interphase
nucleus:
nuclear envelope:
replication: the process of forming an exact copy of something
sister chromatids (chromat-, "color" + -id, "particle"): identical copies of a chromosome, joined at the centromere prior to anaphase of mitosis or anaphase II of meiosis
centromere (centro-, "center" + -mere, "part"): the central part of a chromosome, where the sister chromatids are attached
microtubule organizing center: the organizer of the cytoskeleton
centriole (centri-, "center" + -ole, a diminutive suffix): found in the centrosomes of animal cells
mitotic spindle: the assemblage of microtubules that allow the separation of chromosomes during cell division in eukaryotes
aster (Gk., "star"):
kinetochore: structure that attaches the centromere of a chromosome to the mitotic spindle
IPMAT: a way to remember the order of Interphase Prophase Metaphase Anaphase & Telophase
cleavage furrow: the groove that forms in the cell membrane of animal cells during cytokinesis
cell plate: the newly-forming cell wall between daughter plant cells
meiosis (Gk. "diminution"): the division of a diploid cell that results in four haploid cells
haploid (haplo-, "single" + -oid, "like"): having one set of homologous chromosomes (N)
diploid (diplo-, "double" + -oid, "like"): having two sets of homologous chromosomes (2N)
ploidy (a back-formation from haploid & diploid): refers to the number of sets of homologous chromosomes
homologous chromosomes = homologues (homo-, "same" + -logos, "to say" [agreeing; saying the same thing]): chromosomes that have the same morphology and carry genes that control the same traits
gamete (L. "husband", from gam-, "marriage" [as in bigamy]): haploid sex cells; sperm or eggs
fertilization: the union of two gametes
zygote (from Gk. zygotos, "yoked, joined"): a fertilized egg
ovum [pl. ova] (L. "egg"): egg cell; the female gamete
sperm (from Gk. sperma, "seed"): spermatocyte, the male gamete
synapsis (syn-, "together" + -apsis, "a juncture" [a fastening together]): the pairing up of homologous chromosomes during prophase I
tetrad (Gk. "a group of four"): the group of four chromatids (two from each homologue) that form during synapsis in prophase I
chiasma [pl. chiasmata] (from the Greek letter chi [c]): the X-shaped junction of two chromatids formed during crossing over
crossing over: the phenomenon that occurs during prophase I, whereby portions of homologous chromosomes are swapped
sex chromosome: a chromosome that plays a role in sex determination, in humans (and Drosophila), the X and Y chromosomes -- may have different morphologies (shapes)
autosome (auto-, "same" + chromosome): chromosomes other than sex chromosomes, in which homologous pairs have the same morphology
true-breeding: always producing offspring that resemble self (i.e., homozygous)
gene (from Gk. gen, "birth, race, kind"): a discrete (particulate) unit of hereditary information, located on the chromosomes and composed of DNA
locus [pl. loci] (L. "place"): the position or location on a chromosome occupied by an allele
allele (short for "allelomorph": allelo-, "parallel, of each other" + -morph, "form, shape"): an alternate form of a gene
dominant: a dominant allele is always expressed
recessive: a recessive allele may be masked by a dominant allele, and thus will not be expressed
monohybrid cross (mono-, "one, single"): a cross involving one set of alleles
dihybrid cross (di-, "two"): a cross involving two sets of alleles
homozygous (homo-, "different" + zygous, "zygote"): having two of the same alleles for a given trait
heterozygous (hetero-, "different" + zygous, "zygote"): having two different alleles for a given trait
genotype (geno-, "gene" + -type, "type"): the genetic makeup of an individual
phenotype (pheno-, "showing, visible"[as in "phenomenon"] + -type, "type"): the observable characteristics of an organism
segregation:
independent assortment:
test cross: a cross where an individual with a dominant phenotype is crossed against a homozygous recessive individual; the purpose is to find out the genotype of the dominant individual
incomplete dominance: a situation where the dominant allele is unable to fully mask the recessive allele
multiple alleles: a situation where there are more than two alleles for a given gene
codominance: a situation where there are two or more dominant alleles for a given gene; when they occur together they are both fully expressed, neither masking the other
pleiotropy (pleio-, "more" + -tropy, "to turn, to change"): a situation where one gene affects many of an organisms traits
epistasis (epi-, "upon" + -stasis, "to stand"):
polygenic inheritance (poly-, "many" + -genic, "genes"): when traits are caused by the additive effects of more than one set of genes
linkage: when genes are linked, they are on the same chromosome
linkage map: a chart of the relative positions of gene loci on a chromosome, inferred from crossing over frequencies
sex-linked traits: traits carried on the X chromosome
Barr body: the inactivated X chromosome found in cells of females
element: a substance that cannot be broken down into other substances by ordinary chemical means, e.g., oxygen, sodium, carbon
SPONCH (sulfur phosphorus oxygen nitrogen carbon hydrogen): the most common elements in the molecules that make up living things
atom (a-, "not" + -tom, "cut" [it can't be cut]): the smallest particle of an element, made up of protons, electrons, and (usually) neutrons
nucleus: the center of an atom, made of one or more protons and (usually) neutrons
proton (proto-, "first" + -on, "unit"): a subatomic particle with a mass of one and having a charge of +1
neutron (neutr-, from "neutral" + -on, "unit"): a subatomic particle with a mass of one and having a charge of 0
electron (electr-, from "electricity" + -on, "unit"): a subatomic particle with a mass of 0.0005 and having a charge of -1
atomic number: the number of protons in an atom's nucleus
molecule (L. "little mass"): two or more atoms held together by chemical bonds
covalent bond: a bond formed by the sharing one or more pairs of electrons
compound: a molecule made up of more than one kind on atom
electronegativity: the tendency of one atom to attract electrons in a covalent bond more than another atom does
polar: having an asymmetrical charge distribution
non-polar: having a symmetrical charge distribution
ion: an atom or group of atoms having a positive or negative charge because the number of protons doesn't equal the number of electrons
cation: a positively charged ion: more protons than electrons
anion: a negatively charged ion: more electrons than protons
ionic bond: a chemical bond formed between two ions with opposite charges
hydrogen bond: an intermolecular (weak) bond between a hydrogen atom bound to an oxygen or nitrogen atom, and a strongly electronegative atom (generally N or O) bound to a carbon in another molecule
cohesion:
adhesion:
surface tension:
solute:
solvent:
solution:
hydrophilic (hydro-, "water" + -philios, "love"): having an affinity for water; readily soluble in water
hydrophobic (hydro-, "water" + -phobos, "fear"): lacking an affinity for water; poorly soluble in water
pH (from French; "puissance d'hydrogen", the "power of hydrogen (H)" in a solution -- not the p is uncapitalized, while the H is always uppercase): a scale which measures the abundance of H+ in an aqueous solution, and therefore the solution's acidity
acid: a compound that tends to release H+ in water
base: a compound that tends to take up H+ or release OH- in water
buffer:
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