biology keystones 2

founder effect

genetic drift that occurs after an small number of individuals colonize a new area

frameshift mutation

mutation that involves the insertion or deletion of a nucleotide in the DNA sequence

freezing point

the temperature at which a liquid turns into a solid when cooled

gamete

sex cell; an egg or a sperm cell

gene

a specific region of DNA that codes for a particular protein

gene expression

the process by which a gene gets turned on in a cell to make RNA and proteins

gene recombination

involves the exchange of genetic material either between multiple chromosomes or between different regions of the same chromosome

gene splicing

the process by which the DNA of an organism is cut and a gene perhaps from another organism is inserted

gene therapy

procedure to treat a disease in which a defective or missing gene is replaced or a new gene is inserted into a patient’s genome

genetic drift

change in allele frequencies due to chance alone, occurring most commonly in small populations

genetic engineering

process of changing an organism’s DNA to give the organism new traits

genetically modified organism (gmo)

a plant, animal or microbe in which one or more changes have been made to the genome, typically using high-tech genetic engineering, in an attempt to alter the characteristics of an organism.

genetics incomplete dominance

a form of gene interaction in which both alleles of a gene at a locus are partially expressed, often resulting in an intermediate of different phenotype; a red flower and a white flower would make a pink flower

genotype

collection of all of an organism’s genetic information that codes for traits; RR, rr, and Rr

golgi apparatus

stack of flat, membrane-enclosed spaces containing enzymes that process, sort, and deliver proteins

gradualism

principle that states that the changes in landforms result from slow changes over a long period of time

habitat

combines biotic and abiotic factors fount in the area where an organism lives

herbivore

organism that eats only plants

homeostasis

regulation and maintenance of constant internal conditions in an organism

homologous structure

body part that is similar in structure on different organisms but performs different functions

hypothesis

proposed explanation or answer to a scientific question

impermeable

does not allow molecules to pass through

inference

the process of drawing conclusions base on evidence and reasoning

inheritance

the passing of genetic information from parent to child through the genes in sperm and egg cells

interphase

the phase of the cell cycle in which a typical cell spends most of its life; the cell obtains nutrients and metabolizes them, grows, replicates its DNA in preparation for mitosis, and conducts other “normal” cell functions during this

intracellular

inside a cell/within the cell

isolating mechanisms

characteristic of species that reduce or prevent successful preproduction with members of other species

law (scientific)

statements, based on repeated experiments or observations, that describe or predict a rage of natural phenomena; a basic principle, generalization, regularity or rule that holds true universally under particular conditions

limiting factor

environmental factor that limits the growth and size of a population

lipids

nonpolar molecule composed of carbon, hydrogen, and oxygen; includes fats ad oils

macromolecule

a very large molecule important to biological processes, such as protein or nucleic acid; composed of thousands of covalently bonded atoms; many macromolecules are polymers of monomers

mechanism (scientific)

a system of casually interacting parts and processes that produce one or more effects

meiosis

form of nuclear division that divides a diploid cell into haploid cells; important in forming gametes for sexual reproduction

migration (gentics)

the movement of genetic diversity, usually within a species

mitochondrion

bean-shaped organelle that supplies energy to the cell and has its own ribosomes and dna

mitosis

process by which a cell divides its nucleus and contents

molecule

two or more atoms held together by covalent bonds; not necessarily a compound

monomer

molecular subunit or a polymer

multicellular

having or consisting or many cells

multiple alleles

an allele of a genetic locus having more than two allelic forms within a population

mutation

change in the DNA sequence

mutualism

ecological relationship between two species in which each species gets a benefit from the interaction

natural selection

mechanism by which individuals that have inherited beneficial adaptions produce more offspring on average than do other individuals

niche

the role an organism plays in a community

nondisjunction

the failure of the chromosomes to separate, which produces daughter cells with abnormal number of chromosomes

nonnative species

organisms that do not occur naturally in an area, but are introduced as the result of deliberate or accidental human activities

nucleic acid

polymer of nucleotides; the genetic material or organisms

nucleus

organelle composed of a double membrane that acts as the storehouse of most of a cell’s DNA

observation

using the senses to study the world; using tools to collect measurements; examining previous research results

omnivore

organism that eats both plants and animals

organ

group of different types of tissues that work together to perform a specific function or related functions

organ system

two or more organs that work in a coordinated way to carry out similar functions

organelle

membrane-bound structure that is specialized to perform a distinct process within a cell

organic molecule

a complex molecule that is primarily made of carbon atoms bonded with other elements and/or other carbon atoms

organism

any individual living thing

osmosis

diffusion of water molecules across a semipermeable membrane from an area of higher water concentration to an area of lower water concentration

parasitism

ecological relationship in which one organism benefits by harming another organism

passive transport

movement of molecules across the cell membrane without energy input from the cell

pH

measurement of acidity; related to free hydrogen ion concentration in solution

phenotype

collection of all of an organism’s physical characteristics

photon

elementary particles with no charge, no resting mass, and travel at the speed of light

photosynthesis

process by which light energy is converted to chemical energy; produces sugar and oxygen from carbon dioxide and water

plasma membrane

the membrane found in all cells that separates the interior of the cell from the outside environment

plastids

double-membrane organelles which are found in the cells of plants and algae

point mutation

mutation that involves a substitution of only one nucleotide

polygenic

a characteristic, such as height or skin color, that is influenced by two or more genes

polymer

large, carbon-based molecule formed by monomers

population

all of the individuals of a species that live in the same area

population dynamics

the study of the continuously changing abundance of plants and animals in space and time

predator

organisms that hunt or kill other organisms for food

prey

animals that are killed and eaten by other animals

principle (scientific)

a fundamental truth or proposition that serves as the foundation for a system or belief or behavior or for a chain of reasoning