bio 1

Atoms

Building blocks of matter

Molecules

Chemicals that result from atoms linking together

cell

Basic unit of life

organism

A living thing

tissue

A group of similar cells that perform the same function.

organ

A collection of tissues that carry out a specialized function of the body

organ system

A group of organs that work together in performing vital body functions.

population

A group of individuals that belong to the same species and live in the same area

community

A group of interdependent organisms inhabiting the same region and interacting with each other

ecosystem

A system formed by the interaction of a community of organisms with their physical environment

biosphere

Consists of all life on Earth and all parts of the Earth in which life exists, including land, water, and the atmosphere.

homeostasis

A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level

inheritance

attributes acquired via biological heredity from the parents

taxonomy

Naming and classifying organisms

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

Periodic table of elements

A table that classifies elements by their physical and chemical properties

compounds

2 or more elements chemically combined

organic molecule

Contain Carbon or Hydrogen (ex: sugars, proteins, methane)

biochemistry

Chemistry dealing with chemical compounds and processes in living plants and animals

macromolecule

A very large organic molecule composed of many smaller molecules

polymer

A long molecule consisting of many similar or identical monomers linked together.

dehydration synthesis

A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.

hydrolysis

Breaking down complex molecules by the chemical addition of water

carbohydrate

contain carbon, hydrogen, and oxygen atoms in a ratio of approximately one carbon to two hydrogens to one oxygen

monosaccharide

Monomer of Carbohydrates

disaccharide

A double sugar, consisting of two monosaccharides joined by dehydration synthesis.

polysaccharide

Carbohydrates that are made up of more than two monosaccharides

amino acid

Building blocks of protein

peptide bond

The chemical bond that forms between amino acids

polypeptide

A polymer (chain) of many amino acids linked together by peptide bonds.

denaturation

Loss of normal shape of a protein due to heat or other factor

nucleic acid

A long chain of smaller molecules called nucleotides

nitrogenous base

An organic base that contains nitrogen, a subunit of a nucleotide in DNA and RNA

double helix

Shape of DNA

gene

A segment of DNA on a chromosome that codes for a specific trait

chromosome

Cell structures that carry the genetic material that is copied and passed from generation to generation of cells.

lipid

Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.

phospholipid

A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.

saturated fat

A lipid made from fatty acids that have no double bonds between carbon atoms

unsaturated fat

A fat that has fewer hydrogen atoms because double bonds exist among some of the carbon atoms.

steroid

A type of lipid characterized by a carbon skeleton consisting of four fused rings with various chemical groups attached

heat of vaporization

The amount of energy required for the liquid at its boiling point to become a gas

polar covalent bond

A covalent bond in which electrons are not shared equally

pH scale

measurement system used to indicate the concentration of hydrogen ions (H+) in solution; ranges from 0 to 14

cell theory

(biology) the theory that cells form the fundamental structural and functional units of all living organisms

plasma membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells

organelle

A tiny cell structure that carries out a specific function within the cell

ribosome

organelles at which proteins are synthesized

mitochondria

An organelle in eukaryotic cells that serves as the site of cellular respiration

chloroplast

the site of photosynthesis

cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

nucleus

A part of the cell containing DNA

nucleoid

A dense region of DNA in a prokaryotic cell.

cell wall

A rigid layer of nonliving material that surrounds the cells of plants and some other organisms.

Rough Endoplasmic reticulum

An endomembrane system covered with ribosomes where many proteins are assembled.

Smooth Endoplasmic reticulum

makes lipids

vacuole

A fluid filled organelle that stores enzymes or water

vesicle

a small cavity or sac that contains materials in a eukaryotic cell.

lysosome

An organelle containing digestive enzymes

golgi body

A structure in a cell that receives proteins and other newly formed materials from the endoplasmic reticulum, packages them, and distributes them to other parts of the cell.

daughter cell

The cells that are produced as a result of mitosis. These cells are identical to each other, and also to the original parent cell.

mitosis

Cell division in which the nucleus divides into nuclei containing the same number of chromosomes

meiosis

cell division that produces reproductive cells in sexually reproducing organisms

prophase

Chromosomes become visable, nuclear envelope issolves, spindle forms

metaphase

Chromosomes align themselves along the center of the cells.

haploid

An organism or cell having only one set of chromosomes

diploid

an organism or cell having two sets of chromosomes or twice the haploid number

gamete

Haploid cells (n) for the purpose of sexual reproduction

cancer

A malignant growth or tumor caused by abnormal, uncontrolled cell division.

spindle

tiny fibers that are seen in cell division

cytokinesis

Division of the cytoplasm during cell division

Gregor Mendel

"Father of Genetics"

Dominant

An allele that is always expressed

Recessive

An allele that is masked when a dominant allele is present

Homozygous

An organism that has two identical alleles for a trait

Heterozygous

An organism that has two different alleles for a trait

Genotype

Genetic makeup of an organism

Phenotype

An organism's physical appearance, or visible traits.

Monohybrid Cross

A cross between two individuals, concentrating on only one definable trait

Punnett square

A chart that shows all the possible combinations of alleles that can result from a genetic cross

Principle of segregation

During meiosis, the alleles separate from each other to make the gametes

Microevolution

Change in allele frequencies in a population over generations.

Macroevolution

Evolutionary change above the species level, including the appearance of major evolutionary developments

Hardy-Weinberg Formula

A formula for calculating the frequencies of genotypes in a gene pool from the frequencies of alleles, and vice versa.

Bottleneck effect

A change in allele frequency following a dramatic reduction in the size of a population

Gene flow

Movement of alleles into or out of a population due to the migration of individuals to or from the population

Natural Selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Charles Darwin

1809-1882 English naturalist and scientist whose theory of evolution through natural selection was first published in 'On The Origin of the Species" in 1859.

Sexual selection

A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates.

Genetic drift

A change in the allele frequency of a population as a result of chance events rather than natural selection.

biogeography

Dealing with the geographical distribution of animals and plants

comparative morphology

The study of body plans and structures among groups of organisms

fitness

Contribution that an individual makes to the gene pool of the next generation compared to the contributions of other individuals

adaptation

A trait that helps an organism survive and reproduce

homologous structure

Structures in different species that are similar because of common ancestry.

analogous structure

structures that do not have a common evolutionary origin but are similar in function

Directional selection

Natural selection in which individuals at one end of the phenotypic range survive or reproduce more successfully than do other individuals.

Stabilizing selection

Natural selection that favors intermediate variants by acting against extreme phenotypes

disruptive selection

form of natural selection in which a single curve splits into two; occurs when individuals at the upper and lower ends of a distribution curve have higher fitness than individuals near the middle

geologic dating

dating of earth's history using rocks and fossils