Glossary Terms Flashcards
Adaptation
an inherited characteristic that improves an organism’s ability to survive and reproduce in a particular environment
agglutination
the clumping together of red blood cells or microorganisms in the presence of a specific antibody
alkaptonuria
an inherited metabolic disorder that affects the metabolism of certain amino acids and leads to darkening of the urine to the excretion of homogentisic acid
allele
one of the alternative forms of a gene
allopatric speciation
the formation of two species that occurs when sub-populations of a species are reproductively isolated due to geographic seperation
amino acid
the basic building block of proteins
amniocentesis
a procedure used to recover a sample of amniotic fluid surrounding a fetus in the womb for the purpose of performing genetic tests
amoeboid
having no definite shape, resembling the form or type of movement of an amoeba
anaphase
the third stage of mitosis when sister chromatids split and move toward opposite poles of the cell
antibody
a protein produced by immune cells that binds to a specific antigen to neutralize its effects
anticodon
the triplet of nucleotides in the transfer of RNA that is complementary to a triplet base (codon) in the messenger RNA
antigen
a substance that evokes the production of an antibody
asexual reproduction
a type of reproduction involving only one parent without the fusion of gametes (sperm and egg); usually produces genetically identical offspring
ATP (adenosine triphosphate)
a temporary energy storage molecule for most cells
autophagy
a controlled digestion process in which a cell’s own subcellular organelles are broken down and recycled
autosome
any eukaryotic chromosome other than a sex chromosome
bacteriophage
a virus that infects bacteria
binary fission
a type of asexual reproduction in which a parent cell divides into two genetically identical daughter cells
binomial theorem
the theorem that describes the expansion of any power of a binomial, that is, (a+b)^m
biopsy
the removal of a piece of tissue from a living body for diagnostic studies
biotechnology
the use of molecular techniques in living organisms to manufacture useful products
blending inheritence
a historically influential but factually incorrect notion that organisms contain a blend of traits from their parents
budding
a type of asexual reproduction in which a new organism grows from the body of the parent, eventually detaches from the parent , and lives independently
cancer
a disease caused by abnormally rapid proliferation of body cells
carbohydrate
a sugar that contains carbon, hydrogen, and oxygen in the ratio 1:2:1 (CH2O)
carrier
in genetics, an individual who is heterozygous for a particular trait
cell
the basic structural and functional unit of living organisms
cell cycle
a series of orderly events a eukaryotic cell goes through, from a dividing parent cell to two daughter cells
cell theory
the theory that cells are the basic unit of life and that all cells arise from preexisting cells
cellular respiration
the metabolic pathways by which food molecules are broken down and energy is released and harvested by the cell
central vacuole
a large organelle in plant cells that stores the waste products of metabolism, maintains turgor pressure, and maintains growth
Centrifugation
A laboratory technique in which a sample is spun around a central axis at a high speed to separate its contents based on their size, density, or weight
Centriole
A structure in animal cells composed of bundles of microtubule triplets during cell division
Centromere
A region where sister chromatids (duplicated chromosomes) are joined and to which spindle fibers are attached during cell division
Chorionic villus sampling (CVS)
A procedure in which a sample of the fetal chorionic villa (part of the placenta) is removed for genetic testing
Chromatid
One of a pair of identical chromosomes after DNA replication in the cell cycle
Chromatin
A dispersed DNA-protein complex that makes up eukaryotic chromosomes
Chromatography
A laboratory procedure used to separate and isolate substances in a mixture based on the physical or chemical properties of the constituents
Chromosome
A complex structure in the nucleus of eukaryotes or in the nucleoid region of prokaryotes that is comprised of DNA
cilia (sing. cilium)
short microscopic projections of the cell surface specialized for locomotion
cleavage
the first few cell divisions of an animal zygote
coated pit
a specialized depression on the surface of a cell membrane, formed as a result of receptor-mediated endocytosis
co-dominance
a type of inheritance in which two separate alleles at a locus are equally expressed and produce different phenotypic traits
codon
a triplet of nucleotides in messenger RNA coding for a specific amino acid; the basic unit of the genetic code
conjugation
the transfer of genetic material by joining two bacteria or protists
cystic fibrosis
an often fatal genetic disease characterized by the production of thick mucus that obstructs various ducts in different organs, leading to infection and interference of important functions
cytokinesis
the cytoplasmic division of a cell at the end of mitosis or meiosis, bringing about the separation into two daughter cells
cytological
relating to the science of cytology, a sub-discipline of biology that studies the microscopic structure of cells
cytoplasm
the content of a cell inside the plasma membrane and outside the nucleus
cytoskeletal elements
a network of protein filaments in the cytoplasm of a cell that serves various functions in support, movement and transport: the system includes microtubules, intermediate filaments, and microfilaments
cytosol
the fluid portion of the cytoplasm
deoxyribose
a five-carbon sugar that is a building block of DNA and some nucleotides
DNA (deoxyribonucleic acid)
the genetic material for all organisms except the RNA virus
dominant
describes an allele that determines the phenotype when the genotype is heterozygous
double helix
the spiral shape of a double-stranded DNA molecule
duplication
the production of a second copy of a particular sequence of DNA
electrophoresis
the method of distinguishing molecules, such as a mixture of proteins or DNA, according to their motility in a gel-like substance in an electric field
embryonic
related to an embryo, or being in the state of an embryo
endocytosis
a process by which liquids or solid particles are taken up by a cell through invagination of the plasma membrane
endometrium
the inner epithelial lining of the uterus
endoplasmic reticulum
a network of tubules that is part of the endomembrane system in eukaryotic cells specializing in the synthesis and modification if biological molecules
endosymbiosis
the theory that ancient large eukaryotic cells ingested small prokaryotes, which became subcellular organelles (such as mitochondria and chloroplasts) of the large host cell
epigenetics
the scientific study of changes in the inheritance of traits that occur without changes in the DNA sequence
epistasis
an interaction between two genes in which one gene alters the expression or effect of another gene
erythropoietin
a hormone produced by the kidney in response to low levels of blood oxygen that stimulates the production of red blood cells by the bone marrow
eugenics
the study or practice of altering a population, especially of humans, by controlling fertility and selective breeding for desirable traits
evolution
the process of change by which new species develop from preexisting ancestral species over time
exocytosis
a process by which a vesicle within a cell fuses with the plasma membrane and releases its contents to the outside
exon
the nucleotide sequence of a gene that codes for a protein
familial hypercholesterolemia
an inherited metabolic disorder that results in high levels of blood cholesterol; the disorder is caused by a lack or malfunction of receptors for the low-density lipoprotein (LDL) that removes cholesterol from the blood
flagella (sing. flagellum)
long, whip-like appendages that propel and move cells
functional genomics
the branch of genomics that analyzes the biological function of genes and their products
gemmule
a hypothetical particle postulated to be the hereditary unit (now recognized as incorrect) in the theory of pangenesis
gene
a unit of hereditary consisting of a specific sequence of nucleotides in DNA (or RNA in some viruses)
gene expression
the process by which the information encoded in a gene is converted first into messenger RNA and then to a protein
genetic code
the code relating nucleotide triplets in messenger RNA (or DNA) to amino acids in proteins
genetic drift
a change in the allele frequency in a population that occurs by chance
genetics
a sub-discipline of biology that studies genes and heredity