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different forms of a gene


tiny air sac at the end of a bronchiole in the lungs that provides surface area for gas exchange to occur


compounds that block the growth and reproduction of bacteria


large blood vessels that carry blood from the heart to the tissues of the body


large protein that uses H+ ions to bind ADP and a phosphate group together to produce ATP


large muscular upper chamber of the heart that receives and holds blood that is about to enter the ventricle


strong connective tissue that supports the body and is softer and more flexible than bone

cellular respiration

process that releases energy by breaking down food molecules in the presence of oxygen; made of glycolysis, the Krebs cycle, and the electron transport chain


organism that feeds on plant and animal remains and other dead matter


process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated

down syndrome

if two copies of an autosomal chromosome fail to separate during meiosis, an individual may be born with three copies of a chromosome


organism whose cells contain nuclei


sequence of DNA that codes for protein and thus determines a trait

genetic engineering

process of making changes in the DNA code of living organisms


genetic make up of an organism


iron- containing protein in red blood cells that transport oxygen from the lungs to the tissues of the body


term used to refer to an organism that has two different alleles for the same trait


process by which organisms maintain a relatively stable internal environment


term used to refer to an organism that has two identical alleles for a particular trait


set of photographs for chromosomes grouped in order in pairs


strip of tough connective tissue in a joint that holds bones together

lymph nodes

places where blood cells hang out to fight infection; filters that trap bacteria

lymphatic system

returns excess fluid to the circulation; fights infection and disease


keeps the small intestine in place; anchors all the blood vessels

nervous system

consists of central (brain and spinal cord) and peripheral (all other nerves); coordinates body's response to changes in its internal and external environment


error in meiosis in which homologous chromosomes fail to separate


glands that produce hormones that regulate blood sugar; enzymes that break down carbohydrates, proteins, lipids, and nucleic acids; and sodium bicarbonate, a base that neutralizes stomach acid


organisms that live in or on another organism and harms that organism by feeding on it


disease causing agent, such as bacteria or fungus


chart that shows the relationships within a family


physical characteristics of an organism


process by which plants and some other organisms use light energy to power chemical reactions that convert water and carbon dioxide into oxygen and high- energy carbohydrates such as sugars and starches


cell fragment released by bone marrow


single- celled microorganisms without a nucleus

sex- linked genes

genes located on the X or Y chromosome


process of destroying bacteria using great heat or chemical action


tough connective tissues that join skeletal muscle to bone

Turner's syndrome

only a single X chromosome; sterile female- sex organs don't develop; widened neck; more than 2 nipples


blood vessels that return blood to the heart


regulates body temperature, emotion, hunger, and thirst


sensory and motor integration

pituitary gland

produces hormones


thick layer of heart muscle tissue that contracts and pumps the blood

systolic pressure

force felt in the arteries when the ventricles contract

diastolic pressure

force felt in the arteries when the ventricles are relaxed


when fatty deposits called plaque build up on the walls of arteries

heart attack

when one of the coronary arteries becomes blocked and part of the heart muscle begins to die from lack of oxygen


protein responsible for the ability of blood to clot

lymph fluid

(blood plasma) filters the fluid to remove bacteria and other microorganisms

thymus gland

helps mature T cells (white blood cells) and produce hormones

lymphatic system

supply fluid to circulatory system; fight infection; help in fat absorption


two fist sized organs located near lower back; removes extra water and waste; controls blood pressure; red blood cell regulation; helps maintain chemical balance in body; helps maintain acid base pH; Vitamin D activator


tiny complex structures that filter blood plasma to remove wastes and to control the water and salt concentration of the blood plasma




groups of similar cells that perform a single function


group of tissues that work together to perform a specific function

organ system

a group of organs that perform closely related functions

integumentary system

serves as a barrier against infection and injury; helps regulate body temperature; protection from the sun

respiratory system

provides oxygen needed for cellular respiration and removes excess carbon dioxide from the body

digestive system

converts food into simpler molecules that can be used by the cells of the body; absorbs food

excretory system

eliminates waste products of metabolism from body; maintains homeostasis

skeletal system

supports the body; protects internal organs; allows movement; stores mineral reserves; site for blood cell formation

muscular system

works with skeletal system to produce voluntary movement; helps to circulate blood and movement through the digestive system

circulatory system

brings oxygen, nutrients, and hormones to cells; fights infection; regulates body temperature

endocrine system

controls growth, development, metabolism, and reproduction

reproductive system

produces reproductive cells; in females, nurtures and protects developing embryo

feedback inhibition

process by which the product of a system shuts down the system or limits its operation

epithelial tissue

cover the surface of the body and line internal organs; lining along the chambers of the heart prevents leakage of blood; glands are made of epithelial tissue




blocks dust particles from entering the nose; trap bacteria; brings in molecules that are connected to our nervous system (ole factory)


intersection where food, smells, and breathing pass through


a trap door; when we eat, the door is open; when we swallow, the door closes


(voice box) as air tries to go up and down, it passes through the larynx


cartilage rings


tough fibrous protein; basic structure of hair and nails


dark brown pigment


inner layer of the skin


cells that produce melanin; most people have roughly the same number of melanocytes in the skin


outer layer of the skin

hair follicels

produces hair

white blood cells

leucocytes or phagocytes; no hemoglobin; have nuclei; engulf and/ or destroy invading particles and bacteria; part of the imune system; some escape through capillaries

red blood cells

also called erythrocytes; carries oxygen (attached to hemoglobin) to body cells; carries CO2 away from body cells; made in the bone marrow; no nucelus


55% of the total blood; mixture of 90% water, 8% proteins, .9% minerals; small amounts of amino acids, simple sugars, and metabolic wastes; interstitial fluid or Lymph


humans contain 4 to 6 liters


a collection of organs working together for the common good of the organism


cell fragments that start clotting; release enzymes that build up a fibrous clot to stop bleeding


location at which a neuron can transfer an impulse to another cell; the narrow space between neurons


chemicals used by a neuron to transmit an impulse across a synapse to another cell


the minimum level of a stimulus that is required to activate a neuron

action potential

reversal of charges due to the flow of positive ions into a neuron

sensory neurons

carry impulses from the sense organs to the spinal cord and brain

myelin sheath

an insulating membrane; leaves nodes where the axon membrane is exposed


made up of calcium and phosphorous; living tissue


tough layer of connective tissue surrounding bone

haversian canals

network of tubes running through bone

spongy bone

bone with a latticework structure

compact bone

thick layer of dense beneath the periosteum

somatic nervous system

conscious control; muscle- skeletal movement

autonomic nervous system

unconscious controls; helps maintain homeostasis of body

motor neuron

carries impulses to a muscle or gland to cause action


transfers impulses from one neuron to another

sensory neuron

found near body surfaces to receive stimulus

salavary glands

chemical digestion; digestive enzymes; produce saliva


produces bile; breaks down fats

gall bladder

stores bile

large intestine

removes water


"food tube" between the pharynx and stomach


chemically breaks down food; mechanically breaks down food; hydrochloric acid and pepsin

small intestine

absorbs broken down nutrients


produces something that changes the acids

punctuated equilibrium

a pattern in which species experience long, stable periods interrupted by brief periods of rapid evolutionary change

gene pool

combined genetic information of all members of a particular population

convergent evolution

process by which unrelated organisms independently evolve similarities when adapting to similar environments

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