7th Grade Science: Chapters 1, 2, 3, 7 & 8 (Exam Review, Fall 2010)

199 terms by KQuillen

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temperature

amount of molecular motion in an object

length

amount of distance something is or travels

volume

amount of space an object takes up

mass

amount of matter in an object

weight

amount of pull on an object due to gravity

force

amount of push or pull on an object

standards

liter, meter, gram

standard

1

centi

0.01

milli

0.001

qualitative observations

descriptions based on the 5 senses

quantitative observations

descriptions based on measurements

inference

explanation of events based on observations

standard

anything used as a scale for measurement

calibrate

to mark and number according to a standard

measure

compare an object to a standard

simple data table

created when there is only one trial per level of IV in an experiment

complex data table

created when there are multiple trials per level of IV in an experiment

discrete data

levels of IV that are categories

continuous data

measurements that are numeric

line graph

created when continuous data is collected

bar graph

created when discrete data is collected

variable

something that changes in an experiment

independent variable

factor changed on purpose by the experimenter

dependent variable

data the experimenter will measure and record

constant

factor that does not change in an experiment

hypothesis

prediction of how the IV affects the DV

operational definition

tells how the variable is being measured

experiment

test of the relationship between the IV and DV

data

measurements taken during an experiment

repeated trials

repetitions of an experiment to increase accuracy

scientific method

procedure for testing hypotheses

manipulated variable

another name for the independent variable

responding variable

another name for the dependent variable

step 1

Ask a question

step 2

Form a hypothesis

step 3

Gather materials

step 4

Create am experiment with the steps in the procedure

step 5

Perform the experiment

step 6

Collect data and analyze results

step 7

Form a conclusion

organism

a living thing

cell

the basic unit of structure and function in an organism.

unicellular

single-celled organisms

multicellular

organisms composed of many cells that are specialized to do certain tasks.

stimulus

a change in an organism's surroundings

response

an action or change in behavior as a result of a stimulus.

development

the process of change that occurs during an organism's life to produce a more complex organism.

spontaneous generation

the mistaken idea that living things can arise from nonliving sources.

autotrophs

organisms that make their own food.

heterotrophs

organisms that cannot make their own food.

homeostasis

maintenance of stable internal conditions

classification

the process of grouping things based on their similarities.

taxonomy

the scientific study of how living things are classified.

binomial nomenclature

"two names"

genus

"1st name"; a grouping that contains similar, closely related organisms.

species

group of similar organisms that can mate with each other and produce offspring that can also mate and reproduce.

prokaryotes

organisms whose cells lack a nucleus.

nucleus

a dense area in a cell that contains nucleic acids (the chemical instructions that direct a cell's activities).

eukaryotes

organisms with cells that contain nuclei.

microscope

instrument that makes small objects look larger.

cell theory

1. All living things are composed of cells. 2. Cells are the basic units of structure and function in living things. 3. All cells are produced from other cells.

magnification

ability to make things look larger than they appear.

resolution

sharpness of an image.

electron microscope

a beam of electrons used to magnify an image.

organelle

tiny cell structures that carry out specific functions within the cell.

cell wall

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

cell membrane

the outside boundary that separates the cell from its environment; controls what comes in and out

cytoplasm

the region between the cell membrane and the nucleus.

mitochondria

rod-shaped organelles known as the "powerhouse" of the cell.

endoplasmic reticulum

Passageways that carry proteins around cell

ribosomes

Small, grain-like bodies
Some on ER and some float in cytoplasm
Produce protein

Golgi body

Receive proteins, package and distribute them to cell

chloroplasts

In plant cells only
Capture energy from sunlight to produce food

vacuoles

Large, water filled sacs used for storage
Plants have one big vacuole; some animals have them

lysosome

Small, round structures
Cell's "cleanup crew"
Break down various substances

element

any substance that cannot be broken down into simpler substances.

compound

two or more elements chemically combined

carbohydrate

an energy-rich organic compound made of carbon, hydrogen, and oxygen; examples of sugars and starches.

lipids

energy-rich organic compounds such as fats, oils, and waxes.

proteins

large organic molecules made of carbon, hydrogen, oxygen, nitrogen, and sulfur; found in meat, eggs, fish, nuts, and beans.

amino acids

smallest molecule that makes up proteins; 20 different kinds form thousands of different proteins.

enzyme

type of protein that speeds up a chemical reaction

nucleic acids

very long organic molecules made of carbon, oxygen, hydrogen, nitrogen, and phosphorus. Contain instructions that cells need to carry out all functions of life.

DNA

hereditary genetic information found in chromatin in the nucleus.

RNA

plays an important role in production of proteins.

selectively permeable

some substances can pass through the membrane while others cannot.

diffusion

process by which molecules move from an area of higher concentration to lower concentration.

osmosis

the diffusion of water molecules through a selectively permeable membrane.

passive transport

requires NO cellular energy

active transport

requires cellular energy

transport proteins

cells "pick up" molecules outside the cell and carry them in, using energy.

transport by engulfing

cell membrane surrounds a particle and brings it into the cell

photosynthesis

the process by which a cell captures energy in sunlight and uses it to make food

autotroph

an organism that makes its own food

heterotroph

an organism that cannot make its own food

pigments

absorb light, makes leaves green

chlorophyll

main photosynthetic pigment in chloroplasts

stomata

carbon dioxide enters the plant through these small openings on the undersides of leaves

photosynthesis

the process in which plants and some organisms use energy from the sun to convert carbon dioxide and water into oxygen and sugars

respiration

the process by which cells obtain energy from glucose

fermentation

an energy-releasing process that does not require oxygen

alcoholic fermentation

when yeasts break down sugars for energy; alcohol is a product

lactic acid fermentation

when muscles use up oxygen faster than it can be replaced; lactic acid is the product

cell cycle

the sequence of growth and division for cells; in 3 stages: interphase, mitosis, and cytokinesis

interphase

the stage for cell growth, replication of DNA, and preparation to divide into 2 cells

mitosis

the stage for division of the nucleus; one copy of DNA is distributed into each of the 2 daughter cells.

cytokinesis

the division of the cytoplasm completes the process of cell division

host

Supplies energy to a virus or another organism

endospore

Small resting cell that forms inside a bacterial cell

hidden

Type of virus that may stay inactive for a long period of time

pasteurization

Process of heating food to kill harmful bacteria

flagellum

Long structure that aids in movement

active

Type of virus that multiplies as soon as it enters the cell

inner core

Part of virus containing its genetic information

asexual

reproduction that requires only one parent cell

conjugation

Transfer of genetic information via a threadlike bridge

virus

Tiny, nonliving particle that enters cell to reproduce

prokaryote

Organism that does not have a nucleus

protein coat

Protective part of a virus

parasite

Lives on or in another organism, causing it harm

binary fission

Type of division when one cell divides into 2 identical cells

sexual

Reproduction that requires two parent cells

vaccine

Made from a weakened or altered virus to elicit an immune response

conjugation

One bacterium transfers some genetic to another through a thread-like bridge; then, cells split

endospore

Small, rounded, thick-walled, resting cell that forms inside a bacterial cell. contains cell's genetic material and some of its cytoplasm

pasteurization

Food heated to a temperature that is high enough to kill most harmful bacteria without changing the taste of the food

decomposers

Organisms that break down large chemicals in dead organisms into small chemicals. "nature's recyclers."

protist

Eukaryotes that cannot be classified as animals, plants, or fungi. ("odds and ends.")

protozoan

Animal-like protists; unicellular

pseudopod

Temporary bulges of the cell; form when cytoplasm flows toward one location and the rest of the organism follows-- allows sarcodines to move ("false foot")

contractile vacuole

Structure that collects extra water and expels it from the cell

cilia

Hairlike projections from fells that move with a wavelike motion; used to move and obtain food

symbiosis

A close relationship between organisms in which at least one of the species benefits

mutualism

A close relationship between organisms in which both species benefit

algae

Plantlike protist; autotrophic

spore

Tiny cell that is able to grown into a new organism

fungi

Eukaryotes that have cell walls, are heterotrophs that feed by absorbing their food, and that use spores to reproduce

hyphae

Branching, threadlike tubes that make up the bodies of multicellular fungi

fruiting body

Reproductive structures in which fungi produce spores

budding

A form of asexual reproduction in which no spores are produced; small cell grows from body of parent cell, then breaks away and lives on its own; (unicellular yeast cells)

lichen

Consists of a fungus and either algae or autotrophic bacteria that live together in a mutualistic relationship

amoeba

animal-like protist that moves by way of pseudopod

paramecium

animal-like protist that moves by way of cilia

diatom

unicellular plant-like protist with a glasslike cell wall

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