ileum the middle portion of the small intestine where many nutrients are absorbed (807) immigration the movement of an individual or group into an area (321, 385) immune response the reaction of the body against an antigen (962) immune system the cells and tissues that recognize and attack foreign substances in the body (961) immunity the ability to resist an infectious disease (966) implantation the process by which the newly fertilized egg in the blastocyst stage embeds itself in the lining of the uterus (1057) imprinting learning that occurs early and quickly in a young animal's life and that cannot be changed once learned (891) inbreeding the crossing or mating of plants or animals with close relatives (389)

incisor any of the four cutting teeth located between the canines in the upper and lower jaws (865) incomplete dominance a condition in which a trait in an individual is intermediate between the phenotype of the individual's two parents because the dominant allele is unable to express itself fully (184, 244) incomplete metamorphosis an animal life cycle in which the individual undergoes gradual development through several nymph stages after the egg stage and before the adult stage (748) incurrent siphon a tube through which water enters the body of a bivalve (709) independent assortment the random distribution of the pairs of genes on different chromosomes to the gametes (162) independent variable in an experiment, the factor that is deliberately manipulated, also called the manipulated variable (15)

inducer a substance that combines with and inactivates a repressor which allows the transcription of a gene (219) infectious disease a disease that is caused by pathogenic bacteria, viruses, fungi, or protists (957) inflammatory response a protective response of tissues affected by disease or injury, characterized by redness, swelling, and pain (959) ingestion the process of taking in food (652) innate behavior an inherited behavior that does not depend on the environment or experience (752, 888) insertion in anatomy, the point at which a muscle is attached to a moving bone (921)

insertion mutation a mutation in which one or more nucleotides are added to a gene (240) inspiration the process of taking air from the outside of the body into the lungs (949)

insulin a hormone that is produced by a group of specialized cells in the pancreas and that lowers blood glucose levels (1039)

integument the outer, protective covering of a body, a body part, an ovule, or a sporangium (612, 660) interdependence the dependence of every organism on its connections with other living and nonliving parts of its environment (359) interferon a protein that is produced by cells infected by a virus and that can protect uninfected cells from reproduction of the virus (960) intermediate host a host that gives food and shelter to immature stages of a parasite (693)

internal fertilization fertilization of an egg by sperm that occurs inside the body of a female (786) internal respiration the exchange of gases between the blood and the cells of the body (946)

interneuron a neuron located between the afferent neuron and the final neuron in a neural chain (1013) internode the part of a plant stem between two consecutive nodes (593) interphase a period between two mitotic or meiotic divisions during which the cell grows, copies its DNA, and synthesizes proteins (155) interspecific competition a relationship between two species in which both species compete for limited resources such that both species are negatively affected by the relationship (401) intertidal zone an area along ocean shorelines that lies between low and high water lines (423) intron a segment of a structural gene that is transcribed but not translated (220) inversion a reversal in the order of the genes, or of a chromosome segment, within a chromosome (239) invertebrate an animal that does not have a backbone (651) involuntary muscle a muscle whose movement cannot be controlled voluntarily, such as the cardiac muscle (918) ion an atom, radical, or molecule that has gained or lost one or more electrons and has a negative or positive charge (34) ion channel a complex of protein mole-cules in a cell membrane that form a pore through which ions can pass (102) ionic bond the attractive force between oppositely charged ions, which form when electrons are transferred from one atom to another (34) iris the colored, circular part of the eye (1018)

isopod a crustacean that has seven pairs of identical legs and no carapace; examples include sowbugs and pill bugs (727) isotonic describes a solution whose solute concentration is equal to the solute concentration inside a cell (99) isotope an atom that has the same number of protons (or the same atomic number) as other atoms of the same element do but that has a different number of neutrons (and thus a different atomic mass) (32, 282)

Jacobson's organ an olfactory sac that opens into the mouth and is highly developed in reptiles (827) joint a place where two or more bones meet (915)

How To Bolster Your Immune System

How To Bolster Your Immune System

All Natural Immune Boosters Proven To Fight Infection, Disease And More. Discover A Natural, Safe Effective Way To Boost Your Immune System Using Ingredients From Your Kitchen Cupboard. The only common sense, no holds barred guide to hit the market today no gimmicks, no pills, just old fashioned common sense remedies to cure colds, influenza, viral infections and more.

Get My Free Audio Book

Post a comment