The Violinist's Thumb Vocab

DNA

the chemical of inheritance; genes are made of this molecule

genetics

study of heredity and variation of inherited characteristics

species

group of organisms capable of interbreeding to produce fertile offspring

cell

smallest unit of living organisms

transcribed

copied (from DNA to RNA)

inherited

gained from parents/ancestors as a result of the passing down of genes

primate

order within the class Mammalia; distinguished by having hands, feet and forward-facing eyes

hominid

family within the order primate; includes humans and their fossil ancestors

gene

a heritable factor that consists of a length of DNA and influences a specific characteristic

chromosome

a structure within the cell composed of DNA (and protein) that carries genetic material as a thread-like linear strand of genes (the human species has 23 pairs)

heredity

the passing of a genetic trait from one generation to the next

congenital

a trait present from birth

homunculus

microscopic but fully formed human being from which a fetus was formerly believed to develop

white blood cell

immune system cells of the circulatory system; leukocyte

protein

biochemical formed from a chain of amino acids; contains carbon, hydrogen, oxygen, nitrogen and sulfur

amino acid

the building block of proteins; there are about 20 commonly used by living things on earth

dominant

a version of a trait that will mask the recessive version

recessive

a version of a trait that will be visible only if the dominant version is not inherited

cornea

colorless structure of the eye that covers the iris and pupil; filled with aqueous humor

evolution

change in the heritable characteristics of a species

natural selection

mode of evolution in which some individuals have adaptations that make them more able to survive and reproduce

gradualism/gradual evolution

Darwin's theory regarding the timeline of evolution; very small changes occur over the course of great lengths of time

punctuated equilibrium

Huxley's theory regarding the timeline of evolution; long periods of no change is interrupted by short spurts with many rapid changes

mutate

change, especially with regard to DNA sequences of genes

Drosophila

fruit fly, common model organism for many genetics labs

3:1 ratio

expected outcome of traits in Mendelian crosses

X chromosome

one of two sex chromosomes; in humans and Drosophila, this is the female chromosome

Y chromosome

one of two sex chromosomes; in humans and Drosophila, this is the male chromosome

linked genes

genes (or traits from those genes) on the same chromosome that are frequently inherited together

crossing over

process in which chromosomes from opposite parents trade pieces; this increases genetic variation

nondisjunction

faulty chromosome separation that results in either an extra or a missing chromosome; Downs syndrome results from nondisjunction of chromosome 21

ether

pleasant-smelling colorless liquid that evaporates easily and can be used as an anesthetic

polygenic traits

traits influenced by multiple genes; examples include human eye and skin color

propagation

breeding, replication

radiation

energy released in the form of waves or particles; high-energy radiation such as uv or gamma can damage DNA and increase mutation rate

eugenics

the study or practice of arranging human reproduction to increase the occurrence of "desirable" traits

radioactivity

the emission of ionizing particles or energy; can lead to increased rates of DNA mutation

free radical

highly reactive atom or molecule; has unbonded, lone electrons

cleave

cut, slice

chromosome

molecule of DNA; some chromosomes have protein in addition to DNA

protein

biomolecule composed of groups of amino acids bonded together by peptide bonds; hemoglobin and collagen are examples

Hershey and Chase

pair of scientists who determined that DNA is the molecule of heredity (as opposed to protein)

sulfur

element #16; found in protein but not DNA

phosphorus

element #15; found in DNA but not protein

Watson and Crick

pair of scientists who deduced the double-helix structure of DNA

helix

spiral

complementary

combining in a beneficial way; in DNA, A and T, C and G

template

original version from which a copy is made

RNA

ribonucleic acid; similar to DNA but is single stranded and can leave a nucleus

transcribe

copy DNA in to RNA; use a DNA gene sequence to produce a messenger RNA sequence

ribosome

organelle in cells composed of RNA and protein; site of protein synthesis

translate

use an RNA sequence to build an amino acid sequence (protein)

tRNA

transfer RNA; carries amino acids to the ribosome for protein synthesis

amino acid

monomer of proteins; there are about 20 commonly used in protein synthesis

iteration

repetition

Central Dogma

DNA codes for RNA which codes for proteins; the codes are shared by all living things (mostly)

leukemia

cancer of blood and/or bone marrow

colon

large intestine; site of water absorption following digestion

thyroid

gland located toward the bottom of the neck; produces thyroxin which helps regulate metabolism

helix

extended spiral chain of atoms in a protein or nucleic acid

topoisomerase

enzyme that loosens the supercoiling of DNA; also called gyrase

bacteria

unicellular prokaryotic (no nucleus) cells that can reproduce quickly; cell walls composed of peptidoglycan

expression (of DNA)

activation of gene by promoter proteins and other transcription factors

polymerase

enzyme that binds together nucleotides during DNA replication and RNA transcription

regulatory DNA

sequence of DNA not in a gene that increases or decreases the transcription of the gene

genome

the complete set of genes in a cell or organisms

virus

non-living pathogen composed of protein coat and nucleic acid (DNA or RNA)

archaebacteria

unicellular prokaryotic cells that do NOT have peptidoglycan cell walls; live in anaerobic (no oxygen) environments

restriction enzyme

enzyme that cuts DNA at specific sequences

crossing over

process that occurs during meiosis in which pieces of non-sister chromosomes are traded to increase genetic variation

hormone

chemical messenger transported through circulatory system

phosphate

chemical group that consists of a phosphorous atom and four oxygen atoms, PO₄³⁻

proton

positively charged particle found in the nucleus of an atom

hydrogen bond

electromagnetic force of attraction between one molecule with a partial negative charge and another molecule with a partial positive charge

Chargaff’s Rule

in DNA, the amount of adenine equals the amount of thymine and the amount of guanine equals the amount of cytosine

mitochondria

cell organelle involved in respiration; oxidizes glucose to produce large amounts of ATP

endosymbiosis

theory that proposes mitochondria and chloroplasts were bacteria engulfed by larger cells that formed symbiotic relationship in the evolution of eukaryotic cells

vestigial

structure that has degenerated over evolution and is non-functional

mtDNA

DNA in mitochondria; circular and not associated with histones, similar to bacterial DNA

linear chromosome

chromosome in a line as opposed to a circle; found in nuclei of eukaryotic cells

circular (looped) chromosome

chromosome in a circle as opposed to a line; found in bacteria cells

chloroplast

cell organelle involved in photosynthesis; produces glucose from carbon dioxide and water

squash

lab technique that spreads cells on a microscope slide to make them viewable

transposon

jumping gene

drug resistance

mutation that allows bacteria to survive antibiotic exposure

flora

plant life of a particular region or time period

fauna

animal life of a particular region or time period

Carl Linnaeus

Swedish naturalist credited with popularizing the binomial system of naming organisms

binomial nomenclature

two-name system of classifying and naming organisms; allows for international consistency of naming organisms, shows evolutionary links, and allows for traits of organisms to be predicted

Homo sapiens

scientific name (Genus species) of modern humans

embryo

early stage of development of an organism; between zygote and fetus stages

hox genes

also known as homeoboxes; large groups of genes that direct the formation of many body structures during embryonic stages

conserved genes

genes that are unlikely to change during evolution; usually very important to basic life functions

Vitamin A

sometimes referred to as retinol; fat-soluble vitamin that supports grow of replacement skin cells

golden rice

genetically modified food; has transferred gene for synthesizing beta-carotene

shh gene

also known as sonic hedgehog; codes for a protein that leads to cell specialization in animal embryos

genus

one of the categories of Linnaeus' system; the first of the two names in binomial nomenclature

cartilage

flexible connective tissue found especially in joints; composed primarily of the protein collagen

marrow

soft tissue found in the cavities of bones; site of blood cell production

zygote

fertilized egg