EOC2 Flashcards
a nucleic acid that forms a copy of DNA for use in making proteins.
ribonucleic acid (RNA)
a nucleic acid; the master copy of an organism’s information code that contains the instructions used to form all of an organism’s enzymes and structural proteins.
deoxyribonucleic acid (DNA)
complex biomolecules, such as RNA and DNA, that store cellular information in cells in the form of a code.
nucleic acid
basic building blocks of protein molecules.
amino acids
covalent bond formed between amino acids.
peptide bond
weak chemical bond formed by the attraction of positively charged hydrogen atoms to other negatively charged atoms.
hydrogen bond
a large organic molecule found in living organisms; examples are carbohydrates, lipids, proteins, and nucleic acid.
biomolecule
all of the chemical reactions that occur within an organism.
metabolism
large molecule formed when many smaller molecules bond together.
polymer
measure of how acidic or basic a solution is; the scale ranges from below 0 to above 14.
pH
net, random movement of particles from an area of higher concentration to an area of lower concentration, eventually resulting in even distribution.
diffusion
subunits of nucleic acid formed from a simple sugar, a phosphate group, and a nitrogenous base.
nucleotides
type of protein found in all living things that changes the rate of chemical reactions.
enzymes
organelle in eukaryotic cells with a system of flattened tubular membranes; sorts and packs proteins and sends them to their appropriate destinations.
Golgi apparatus
instrument that uses light and a series of lenses to magnify objects in steps; can magnify an object up to 1500 times its original size.
compound light microscope
flexible boundary between the cell and its environment; allows materials such as water and nutrients to enter and waste products to leave.
plasma membrane
instrument that uses a beam of electrons instead of light to magnify structures up to 500 000 times actual size; allows scientists to view structures within a cell.
electron microscope
structural model of the plasma membrane where molecules are free to move sideways within a lipid bilayer.
fluid mosaic model
feature of the plasma membrane that maintains homeostasis within a cell by allowing some molecules into the cell while keeping others out.
selective permeability
organelle in eukaryotic cells with a series of highly folded membranes surrounded in cytoplasm.
endoplasmic reticulum
basic unit of all organisms; all living things are composed of these.
cell
fairly rigid structure located outside the plasma membrane of plants, fungi, most bacteria, and some protists; provides support and protection.
cell wall
the theory that (1) all organisms are composed of one or more cells, (2) the cell is the basic unit of structure and organization of organisms, (3) all cells come from preexisting cells.
cell theory
chlorophyll-containing organelles found in the cells of green plants and some protists; capture light energy and converted it to chemical energy.
chloroplasts
clear, gelatinous fluid in cells that is the site of numerous chemical reactions, in eukaryotic cells, it suspends the cell’s organelles.
cytoplasm
eukaryotic membrane-bound organelles that transform energy stored in food molecules; has a highly folded inner membrane that produces energy-storing molecules.
mitochondria
in eukaryotic cells, the central membrane-bound organelle that manages cellular functions and contains DNA.
nucleus
lipids with an attached phosphate group; plasma membranes are composed of phospholipid bilayer with embedded proteins.
phospholipids
long projections composed of microtubles; found on some cell surfaces; they help propel cells and organisms by a whiplike motion.
flagella
long strands of DNA found in the eukaryotic cell nucleus; condense to form chromosomes.
chromatin
membrane-bound space in the cytoplasm of cells used for the temporary storage of materials.
vacuole
membrane-bound structures with particular functions within eukaryotic cells.
organelles
nonmembrane-bound organelles in the nucleus where proteins are assembled.
ribosomes
organelle in eukaryotic cell nucleus that produces ribosomes.
nucleolus
organelles that contain digestive enzymes; digest excess or worn out organelles, food particles, and engulfed viruses or bacteria.
lysosomes
process of maintaining equilibrium in cells’ internal environments.
homeostasis
short, numerous, hairlike projections composed of pairs of microtubules; frequently aid in locomotion.
cilia
unicellular or multicellular organisms, such as yeast, plants, and animals, composed of eukaryotic cells, which contain a true nucleus and membrane-bound organelles.
eukaryotes
unicellular organisms, such as bacteria, composed of prokaryotic cells; lack internal membrane-bound structures.
prokaryotes
identical halves of a duplicated parent chromosome formed during the prophase stag of mitosis; the halves are held together by a centromere.
sister chromatids
passibe transport of materials across a plasma membrane by transport proteins embedded in the plasma membrane.
facilitated diffusion
in cells, solution in which the concentration of dissolved substance in the solution is the same as the concentration of dissolved substances inside a cell.
isotonic solution
in cells, solution in which the concentration of dissolved substances is lower in the solution outside the cell than the concentration inside the cell.
hypotonic solution
in cells, solution in which the concentration of dissolved substances outside the cell is higher than the concentration inside the cell.
hypertonic solution
multiple organs that work together to perform a specific life function.
organ system
energy-expending process by which cells transport materials across the cell membrane against a concentration gradient.
active transport
movement of particles across cell membranes by diffusion or osmosis; the cell uses no energy to move particles across the membrane.
passive transport
active transport process by which materials are secreted or expelled from a cell.
exocytosis
active transport process where a cell engulfs materials with a portion of the cell’s plasma membrane and releases the contents inside of the cell.
endocytosis
continuous sequence of growth (interphase) and division (mitosis) in a cell.
cell cycle
cell growth where a cell increases in size, carries on metabolism, and duplicates chromosomes prior to division.
interphase
cell process following meiosis or mitosis in which the cell’s cytoplasm divides and separates into new cells.
cytokinesis
cell structure that joins two sister chromatids of a chromosome.
centromere
cell structures composed of microtubule fibers; forms between the centrioles during prophase and shorten during anaphase, pulling apart sister chromatids.
spindle
cell structures that carry the genetic material that is copied and passed from generation to generation.
chromosomes
diffusion of water across a selectively permeable membrane depending on the concentration of solutes on either side of the membrane.
osmosis
final phase of mitosis during which new cells prepare for their own independent existence.
telophase
first and longest phase of mitosis where chromatin coils into visible chromosomes.
prophase
group of two or more tissues organized to perform complex activities within an organism.
organ
groups of cells that work together to perform a specific function.
tissue
in animal cells, a pair of small cylindrical structures composed of microtubules that duplicate during interphase and move to opposite ends of the cell during prophase.
centrioles
period of nuclear cell division in which two daughter cells are formed, each containing a complete set of chromosomes.
mitosis
segment of DNA that controls the protein production and the cell cycle.
gene
short second phase of mitosis where doubled chromosomes move to the equator of the spindle and chromatids are attached by centromeres to a separate spindle fiber.
metaphase
third phase of mitosis in which the centromeres split and the chromatid pairs of each chromosome are pulled apart by microtubules.
anaphase
uncontrolled cell division that may be caused by environmental factors and/or changes in enzyme production in the cell cycle.
cancer
in cellular respiration, series of chemical reactions that break down glucose and produce ATP.
citric acid cycle
series of anaerobic chemical reactions in which pyruvic acid uses NADH to form lactic acid and NAD+, which is then used in glycolysis.
lactic acid fermentation
series of reactions during the light-independent phase of photosynthesis in which simple sugars are formed from carbon dioxide using ATP and hydrogen from the light-dependent reactions.
Calvin cycle
chemical process where mitochondria break down food molecules to produce ATP.
cellular respiration
series of proteins embedded in a membrane along which energized electrons are transported; as electrons are passed from molecule to molecule, energy is released.
electron transport chain
chemical reactions that do not require the presence of oxygen.
anaerobic
chemical reactions that require the presence of oxygen.
aerobic
energy-storing molecule in cells composed of an adenosine molecule, a ribose sugar and three phosphate groups; energy is stored in the molecule’s chemical bonds and is used quickly and easily by cells.
ATP
in cellular respiration, series of annaerobic chemical reactions in the cytoplasm that breaks down glucose into pyruvic acid; forms a net profit or two ATP molecules.
glycolysis
light-absorbing pigment in plants and some protists that is required for photosynthesis; absorbs most wavelenths of light except for green.
chlorophyll
phase of photosynthesis where light energy is converted to chemical energy in the form of ATP; results in the splitting of water and the release of oxygen.
light-dependent reactions
phase of photosynthesis where energy from light-dependent reactions is used to produce glucose and additional ATP molecules.
light-independent reactions
molecule formed from the breaking off of a phosphate group for ATP; results in a release of energy that is used for biological reactions.
ADP
process by which autorophs, such as algae and plants, trap energy from sunlight with chlorophyll and use this energy to convert carbon dioxid and water into simple sugars.
photosynthesis
mistaken idea that life can arise from nonliving materials.
spontaneous generation
chemosynthetic prokaryotes that live in harsh environments, such as deep-sea vents and hot springs.
archaebacteria
physical evidence of an organism that lived long ago that scientists use to study the past; evidence may appear in rocks, amber, or ice.
fossil
alteration of allelic frequencies in a population by chance events; results in disruption of genetic equilibrium.
genetic drift
condition in which the frequency of alleles in a population remains the same over generations.
genetic equilibrium
evolution in which distantly related organisms evolve similar traits; occurs when unrelated species occupy similar environments.
convergent evolution
evolution in which species that once were similar to an ancestral species diverge; occurs when populations change as they adapt to different environmental conditions.
divergent evolution
occurs when formerly interbreeding organisms can no longer produce fertile offspring due to an incompatibility of their genetic material or by differences in mating behavior.
reproductive isolation
occurs whenever a physical barrier divides a population, which results in individuals no longer being able to mate
geographic isolation
all of the alleles in a population’s genes.
gene pool
divergent evolution in which ancestral species evolve into an array of species to fit a number of diverse habitats.
adaptive radiation
mechanism for change in populations; occurs when organisms with favorable variations survive, reproduce, and pass their variations to the next generation.
natural selection
process of breeding organisms with specific traits in order to produce offspring with identical traits.
artificial selection
a structure in a present-day organism that no longer serves its natural prupose, but was probably useful to an ancestor; provides evidence of evolution.
vestigial structure
structures that do not have a common evolutionary origin but are similar in function.
analogous structures
structures with common evolutionary orgins; can be similar in arrangement, in function, or both.
homologous structures
earliest stage of growth and development of both plants and animals; differences and similarities among these can provide evidence of evolution.
embryo
idea that species originate through a gradual change of adaptations.
gradualism
process of evolution of new species that occurs when members of similar populations no longer interbreed to produce fertile offspring within their natural environment.
speciation
structural adapation that enables one species to resemble another species; may provide protection from predators or other advantages.
mimicry
structural adaptation that enables species to blend with their surroundings; allows a species to aviod detection by predators.
camouflage
primate characteristic of having a thumb that can cross the palm and meet the other fingertips; enables animal to grasp and cling to objects.
opposable thumb
ability to walk on two legs; leaves arms and hands free for other activities such as hunting, protecting young, and using tools.
bipedal
group of mammals including lemurs, monkeys, apes, and humans that evolved from a common ancestor.
primate
two-word system developed by Carolus Linnaeus to name species.
binomial nomenclature
biological classification system based on phylogeny; assumes that as groups of organisms diverge and evolve from a common ancestral group, they retain derived traits.
cladistics (cladogram)
branch of biology that groups and names organisms based on studies of thier shared characteristics.
taxonomy
branching diagram that models the phylogeny of a species based on the derived traits of a group of organisms.
cladogram
diverse group of multicullular or unicellular eukaryotes that lack complex organ systems and live in moist environments; may be autotrophic or heterotrophic.
protist
first word of a two-part scientific name used to identify a group of similar species.
genus
group of prokaryotes with strong cell walls and a variety of structures, may be autotrophs (chemosynthetic or photosynthetic) or heterotrophs.
eubacteria
group of unicellular or multicellular heterotrophic eukaryotes that do not move from place to place; absorb nutrients from organic materials in the environment.
fungus
grouping of objects or information based on similarities.
classification
