SCI TERM EXAM

homeostasis

the body’s ability to maintain a stable internal environment despite external changes

negative feedback

feedback mechanism that stops the problem

positive feedback

feedback mechanism that keeps the process going

nervous system

system that sends quick impulses to trigger responses

endocrine system

system that releases hormones to regulate blood sugar and temperature

circulatory system

system that transports nutrients and oxygen and removes wastes

indicators of homeostasis

measurable factors used to determine whether the body’s internal conditions are being maintained properly

body temperature, blood glucose, blood pressure

three indicators of homeostasis

35.6-37.8

normal body temperature

vasodilation

sweating - process where blood vessels near the surface of the skin widen

vasoconstriction

shivering - blood vessels near the skin narrow. blood is redirected away from the skin surface and toward deeper tissues

hypothalamus

part of the brain that acts like a thermostat

hyperthermia

abnormally high body temperature

hypothermia

abnormally low body temperature

blood glucose

indicator of homeostasis - amount of sugar or glucose present in the blood

70-100 mg/dL

normal fasting blood glucose levvel

insulin

hormone released by the pancreas when blood glucose level is high

glucagon

hormone released by the pancreas when blood glucose is low

glycogen

glucagon signals the liver to break down ____

diabetes

condition in which blood glucose levels become too high

blood pressure

indicator of homeostasis - force created when blood presses against the walls of arteries as the heart pumps

120/80 mm Hg

normal blood pressure

hypertension

long-term high blood pressure

receptor, control center, effector

three main components of a feedback mechanism

population dynamics

changes in the size and characteristics of populations

birth rate, death rate, immigration, emigration

four factors of population growth

birth rate

factor of population growth - the number of individuals born; increases the population

death rate

factor of population growth - the number of individuals that die; decreases the population

immigration

factor of population growth - individuals move into a population; increases the population

emigration

factor of population growth - individuals move out of a population; decreases the population

population density, spatial distribution, geographic range, age structure, reproductive patterns

five population characteristics

population density

population characteristic - number of individuals occupying a particular area

spatial distribution

population characteristic - how individuals are spaced within an area

uniform distribution

type of spatial distribution - individuals are evenly spaced

clumped distribution

type of spatial distribution - individuals occur in groups

random distribution

type of spatial distribution - individuals are scattered without a predictable pattern

geographic range

population characteristic - area inhabited by a population

age structure

population characteristic - distribution of individuals among age groups

reproductive pattern

population characteristic - different ways organisms produce and care for their offspring to increase their chances of survival

population growth

change in the number of individuals in a population over time

exponential growth

model of population growth - occurs when a population grows rapidly because resources are abundant and environmental conditions are favorable

J

_-shaped graph for exponential growth

logistic growth

model of population growth - occurs when population growths slows because environmental resources become limited

s

_-shaped graph for logistic growth

carrying capacity

maximum number of individuals that an environment can support over time

density-independent factors

type of limiting factor - affect populations regardless of population size

density-dependent factors

type of limiting factor - become stronger as the population becomes larger

acids

substances that produces hydrogen ions when dissolved in water

hydrochloric acid

common acid - also known as muriatic acid. a strong corrosive acid that is naturally found in gastric juice inside our stomach

nitric acid

common acid - widely used in industries for producing fertilizers, explosives, dyes, and pharmaceuticals

sulfuric acid

common acid - widely used in industries for producing fertilizer, refining petroleum, batteries, toilet bowl cleaners, and waste water treatment

acetic acid

common acid - main component of vinegar. used as a food preservative, food additive, cleaning solution, descaling agent, and pH adjuster

bases

substances that produce hydroxide ions when dissolved in water

bitter, slippery

bases are described as ___ and ____

ammonia

common bases - a colorless gas with a very pungent odor. widely used in homes and industries. used in the production of fertilizers, explosives, refrigerants, and household cleaning agents

calcium hydroxide

common bases - also called slaked lime. used in construction, agriculture, food production, and to neutralize acidic soil

sodium hydroxide

common bases - a white solid that forms a strong alkaline solution when dissolved in water. used in soap production, paper production, and the petroleum industry

salt

ionic compound composed of cations and anions

sodium bicarbonate

common salts - also known as baking soda. used as a leavening agent in baking, antacid, cleaning, and deodorizer

sodium carbonate

common salts - also called washing soda. used for cleaning and removing contaminants from water

magnesium sulfate

common salts - also called epsom salt. used to relieve muscle pain, acts as a laxative, and increases magnesium in soil

calcium chloride

common salts - used to melt road ice, as a food firming agent, and as a calcium source

ammonium chloride

common salts - used as a fertilizer, electrolyte, and as a soldering flux

power of hydrogen

pH

pH

quantitative measure of the acidity or basicity of liquids or aqueous solutions

acidic

low ph → more ____

basic

high ph → more ____

combination

types of chemical reactions - occurs when 2 or more substances combine to form one product

decomposition

types of chemical reactions - occurs when 1 compound breaks down into 2 or more simpler substances

single replacement

types of chemical reactions - occurs when 1 element replaces another element in a compound

double replacement

types of chemical reactions - occurs when 2 compounds exchange ions to form 2 new compounds

chemical equation

representation of a chemical reaction

coefficients

numbers written before a symbol or formula that indicate the quantities of each substance

reactants

substances written on the left side of the equation

products

substances written on the right side of the equation

subscript

small number that indicates the number of atoms in each molecule

g

state symbol for gas

s

state symbol for solid

l

state symbol for liquid

aq

state symbol for dissolved in water

H2

hydrogen gas

HCl

hydrogen chloride

CaCO3

calcium carbonate

CaO

calcium oxide

CO2

carbon dioxide

Na

sodium

NaCl

sodium chloride

Zn

zinc

S

sulfur

ZnS

zinc sulfide

CO

carbon monoxide

O2 (g)

oxygen gas

law of conservation of mass

states that matter/mass is neither created nor destroyed