Bio exam 1

Biology

The scientific study of life

Evolution

any gradual change; the genetic and resulting phenotypic change in populations of organisms from generation to generation

Nucleic acids

a polymer made up of nucleotides, specialized for the storage, transmission, and expression of genetic information; DNA and RNA are nucleic acids

Proteins

a long-chain polymer of amino acids with 20 different common side chains. Occurs with its polymer chain extended in fibrous proteins, or coiled into a compact macromolecule in enzymes and other globular proteins. The component amino acids are encoded in the triplets of messenger RNA, and proteins are the products of genes

Liposomes

a spherical structure contained by a membrane of phospholipids. Can be used to deliver drugs to cells

Prokaryotes

unicellular organisms that do not have nuclei or other membrane-enclosed organelles. Includes Bacteria and Archaea

Bacteria

one of the two primary divisions of life. Unicellular organisms lacking a nucleus, possessing distinctive ribosomes and initiator tRNA, and generally containing peptidoglycan in the cell wall.

Archaea

one of the two primary divisions of life. Often used for only prokaryotic archaea, which are unicellular organisms that lack a nucleus and lack peptidoglycan in the cell wall. Likely related to lokiarchaeota

Eukaryotes

a group of organisms made up of one or more complex cells in which the genetic material is contained in nuclei. Includes plants, fungi, and animals.

Nucleus

in cells: the centrally located compartment of eukaryotic cells that is bounded by a double membrane and contains the chromosomes

Metabolism

the sum total of the chemical reactions that occur in an organism, or some subset of that total (as respiratory metabolism)

Photosynthesis

the metabolic process carried out by green plants and some microorganisms by which visible light is trapped and the energy used to synthesize compounds such as ATP and glucose.

Cyanobacteria

a group of unicellular, colonial, or filamentous bacteria that conduct photosynthesis using chlorophyll

Aerobic metabolism

occurring in the presence of oxygen

Anaerobic metabolism

occurring without the use of molecular oxygen

Cellular specialization

in multicellular organisms, the division of labor such that different cell types become responsible for the different functions (e.g. reproduction or digestion) within the organism

Tissues

a group of similar cells organized into a functional unit; usually integrated with other tissues to form part of an organ

Organs

a body part, such as the heart, liver, brain, root, or leaf. Organs are composed of different tissues integrated to perform a distinct function. Integrated into organ systems

Organ systems

an interrelated and integrated group of tissues and organs that work together in a physiological function

Internal environment

in multicellular organisms, the extracellular body fluids (interstitial/tissue) that bathe the cells of the body and therefore constitute the immediate environment of the cells

Homeostasis

the maintenance of a steady state, such as a constant temperature, by means of physiological or behavioral feedback responses

Sensory mechanisms

the means by which internal or external stimuli are converted into neural signals

Effector mechanisms

adaptations that enable an organism to alter its physiological or behavioral state

Signaling mechanisms

the means of transferring information between cells, organs, and organisms

Community

a group of species living together at the same time and place

Ecosystem

the organisms of a particular community together with the physical and chemical environment in which they live

Biomes

a major division of the ecological communities of Earth, characterized primarily by distinctive vegetation and annual patterns of temperature and precipitation.

Biosphere

all regions of Earth (terrestrial and aquatic) and Earth's atmosphere in which organisms can live

Genes

a unit of heredity. Used as the unit of gene function that carries the information for a polypeptide or RNA

Genetics

the scientific study of the structure, functioning, and inheritance of genes

Deoxyribonucleic acid (DNA)

the fundamental hereditary material of all living organisms. In eukaryotes, stored primarily in the cell nucleus. A nucleic acid using deoxyribose rather than ribose

Genome

the complete DNA sequence for a particular organism or individual

Nucleotides

the basic chemical unit in nucleic acids, consisting of a pentose sugar, a phosphate group, and a nitrogen-containing base

Transcribing

the synthesis of RNA using one strand of DNA as a template

Ribonucleic acid (RNA)

an often single-stranded nucleic acid whose nucleotides use ribose rather than deoxyribose and in which the base uracil replaces thymine found in DNA. seres as a genome for some viruses

Mutations

a change in the genetic material not caused by recombination

Population

any group of organisms coexisting at the same time and in the same place and capable of interbreeding with one another

Natural selection

the different contribution of offspring to the next generation by various genetic types belonging to the same population. The mechanism of evolution proposed by Charles Darwin

Adaptations

In evolutionary biology, a particular structure, physiological process, or behavior that makes an organism better able to survive and reproduce. Also, the evolutionary process that leads to the development or persistence of such a trait

Genomics

the scientific study of entire sets of genes and their interactions

Bioinformatics

the use of computer programs and mathematical approaches to analyze complex biological data, such as DNA sequences

Phylogenetic trees

a graphic representation of the lines of descent among organisms or their genes

Binomial

a taxonomic naming system in which each species is given a binomial, a genus name followed by a species name

Genus

a group of related, similar species recognized by taxonomists with a distinct name used in binomial nomenclature

Data

quantified observations about a system under study

Inductive logic

a logical thought process that involves making observations and then formulating one or more hypotheses that might explain those observations

Hypothesis

a tentative answer to a question, from which testable predictions can be generated

Deductive logic

a logical thought process that starts with a premise believed to be true, then predicts what facts would also have to be true to be compatible with that premise

Controlled experiments

manipulate one factor of interest while holding other variables constant as a means of testing the influence of the manipulated variable

Comparative experiments

compare data gathered from different populations that differ in multiple, unknown ways

Null hypothesis

the premise that any differences observed in an experiment are simply the result of random differences that arise from drawing two finite samples from the same population\

Model systems

the small group of species that are the subject of extensive research. Organisms that adapt well to laboratory situations, and findings from experiments on them can apply across a broad range of species (e.g., mice, zebrafish, fruit flies, and e. coli)

Cell theory

the theory that cells are the basic structural and physiological units of all living organisms, and that all cells come from preexisting cells

Surface area-to-volume ratio

for any cell, organism, or geometrical solid, the ratio of surface area to volume; this is an important factor in setting an upper limit on the size a cell or organism can attain

Cell membrane

the membrane that surrounds the cell, regulating the entry and exit of molecules and ions. Every cell has a cell membrane

Cytoplasm

the contents of the cell, excluding the nucleus

Cytosol

the fluid portion of the cytoplasm, excluding organelles and other solids

Prokaryotes

unicellular organisms that do not have nuclei or other membrane-enclosed organelles

Eukaryotes

organisms whose cells contain their genetic material inside a nucleus. Includes all life other than viruses, archaea, and bacteria

Organelles

any of the membrane-enclosed structures within a eukaryotic cell. E.g., nucleus, endoplasmic reticulum, mitochondria, etc.

Nucleus

the centrally located compartment of eukaryotic cells that is bounded by a double membrane and contains the chromosomes

Nucleoid

the region that harbors the chromosomes of a prokaryotic cell. NOT bound by a membrane

Ribosomes

small particles in the cell that are the sites of protein synthesis

Cell wall

a relatively rigid structure that encloses cells of plants, fungi, many protists, and most prokaryotes, and which gives these cells their shape and limits their expansion in hypotonic media

Outer membrane

in organelles that have two membranes such as chloroplasts and mitochondria, the outer membrane encloses the entire organelle

Capsule

in some prokaryotes, a dense layer of polymers that surrounds the cell wall

Internal membrane

a membrane that is enclosed within a membrane-bound organelle. E.g., the membrane around thylakoids in chloroplasts and the inner mitochondrial membrane.

Flagella

a long, whiplike appendage that propels cells. Prokaryotic flagella differ greatly from eukaryotes

Pili

a structure that links prokaryote cells at the beginning of conjugation

Cytoskeleton

the network of microtubules and microfilaments that gives a eukaryotic cell its shape and its capacity to arrange its organelles and move

Nucleolus

a small, generally spherical body found within the nucleus of eukaryotic cells. The site of synthesis of ribosomal RNA

Nuclear envelope

a double membrane that encloses the cell nucleus

Chromatin

the nucleic acid-protein complex that makes up eukaryotic chromosomes

Chromosomes

in bacteria and viruses, the DNA molecules that contain most or all of the genetic information of the cell or virus. In eukaryotes, a structure composed of DNA and proteins that bear part of the genetic information of the cell

Endomembrane system

a system of intracellular membranes that exchange material with one another, consisting of the Golgi apparatus, endoplasmic reticulum, and lysosomes when present

Vesicles

within the cytoplasm, a membrane-enclosed compartment that is associated with other organelles; e.g., Golgi apparatus

Endoplasmic reticulum (ER)

a system of membranous tubes and flattened sacs found in the cytoplasm of eukaryotes. Rough ER: ribosomes, smooth ER: no ribosomes

Golgi apparatus

a system of concentrically fouled membranes found in the cytoplasm of eukaryotic cells; function in secretion from the cell by exocytosis

Primary lysosomes

a lysosome before fusion with an endosome

Phagocytosis

the process by which a cell uses its cell membrane to enclose and engulf a macromolecule or particle in the extracellular environment

Secondary lysosome

a membrane-enclosed organelle formed by the fusion of a primary lysosome with a phagosome, in which macromolecules are taken up by phagocytosis are hydrolyzed into their monomers

Exocytosis

a process by which a vesicle in a cell fuses with the cell membrane and releases its contents to the outside

Autophagy

the programmed destruction of a cell's components

Lysosomal storage diseases

a class of human diseases, invariably harmful or fatal, that are caused by the failure of lysosomes to digest specific cellular components. E.g., Tay-Sachs disease

Mitochondria

energy-generating organelles in eukaryotic cells that contain the enzymes of the citric acid cycle, the respiratory chain, and oxidative phosphorylation

Chloroplasts

an organelle bounded by a double membrane containing the enzymes and pigments that perform photosynthesis. Occur ONLY in eukaryotes

Thylakoids

a flattened sac within a chloroplast. Contain all of the chlorophyll in a plant, in addition to the electoral carriers of photophosphorylation. Stack together to form grana

Peroxisomes

an organelle that houses reactions in which toxic peroxides are formed and then converted to water

Glyoxysomes

a plant organelle in which stored lipids are converted to carbohydrates

Vacuoles

a membrane-enclosed organelle in plant cells that can function for storage, water concentration for turgor, or hydrolysis of stored macromolecules

Microfilaments

in eukaryotic cells, a fibrous structure made up of actin monomers. Play roles in the cytoskeleton, cell movement, and muscle contraction

Actin

a protein that makes up the cytoskeletal microfilaments in eukaryotes and is one of two contractile proteins in muscles

Intermediate filaments

a part of the cytoskeleton that includes filament intermediate in diameter between microtubules and microfilaments

Microtubules

tubular structures found in the centrioles, spindle apparatus, cilia, flagella, and cytoskeleton of eukaryotes. Play roles in the motion and maintenance of the shape of eukaryotes

Tubulin

a protein that polymerizes to form microtubules

Motor proteins- specialized proteins that use energy to change shape and move cells or structures within cells

Kinesins

a type of protein that binds to microtubules and vesicles. By moving along microtubules, kinesins act as motor proteins to move attached vesicles

Dyneins

a type of protein that binds to microtubules and causes bending in cilia and flagella

Cilia

hairlike organelles used for locomotion by many unicellular organisms and for moving water and mucus by many multicellular organisms. Generally shorter than flagella

Plasmodesmata

in plants, membrane-lined channels that extended through the cell walls and connect the cytoplasm of adjacent cells