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199 terms

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

STUDY
PLAY
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
kilo
1000
hecto
100
deka
10
standards
liter, meter, gram
standard
1
deci
0.1
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
dinoflagellate
unicellular plant-like protist that glows in the dark
euglenoid
unicellular plant-like protist that moves by way of flagella
red algae
multicellular plant-like protist used to make ice cream and conditioner
brown algae
multicellular plant-like protist that includes common seaweed and kelp (contain bladders so they can stand upright)
green algae
multicellular plant-like protists that contain chlorophyll like common plants
cuticle
waxy, waterproof layer that covers the leaves of most plants; helps reduce water loss
vascular tissue
system of tubelike structures inside a plant through which water, minerals, and food move
zygote
fertilized egg cell
nonvascular plant
lack a well-developed system of tubes for transporting water and other materials
vascular plant
have a well-developed system of tubes for transporting water and other materials; can grow tall b/c of increased strength, stability, and support
sporophyte
(stage in which) plant produces spores
gametophyte
(stage in which) plant produces two kinds of sex cells: sperm cells and egg cells
rhizoid
thin, root-like structures which anchor moss and absorb water and nutrients from the soil
frond
leaves of a fern; upper surface coated with cuticle that helps plant retain water
phloem
vascular tissue through which food moves
xylem
vascular tissue through which water and minerals move
pollen
tiny structures that contain the cells that will later become sperm cells
seed
a structure that contains a young plant inside a protective covering (protect it from drying out)
embryo
the young plant that develops from the zygote
cotyledon
seed leaves of the embryo
germination
occurs when the embryo begins to grow and pushes out of the seed .
root cap
protects the root from injury from rocks as the root grows through the soil
cambium
layer of cells which divide to produce new phloem and xylem
transpiration
the process by which water evaporates from a plant's leaves
gymnosperm
a seed plant that produces naked seeds
cone
reproductive structure of most gymnosperms; covered with scales
ovule
a structure that contains an egg cell
pollination
the transfer of pollen from a male reproductive structure to a female reproductive structure
angiosperms
share 2 important traits:
1) produce flowers
2) produce seeds that are enclosed in fruits
flower
the reproductive structure of an angiosperm
sepal
leaf-like structures that protect the developing flower (bud); often green in color
petal
generally most colorful part of flower; attracts pollinators with color and scent
stamens
a flower's male reproductive parts
pistils
a flower's female reproductive parts; found in the center of most flowers
ovary
hollow structure in the pistil which protects seeds as they develop
fruit
a ripened ovary and other structures that enclose one or more seeds
monocots
angiosperms that only have one seed leaf
examples: grasses
dicots
produce seeds with two seed leaves
examples: food plans like beans and apples
tropism
a plant's growth response toward or away from a stimulus
hormone
a chemical that affects how the plant grows and develops
auxin
a plant hormone that speeds up the rate at which a plant's cells grown and controls a plant's response to light
photoperiodism
a plant's response to seasonal changes in length of night and day
short-day plants
these plants flower when nights are LONGER than a critical length
long-day plants
these plants flower when nights are SHORTER than a critical length
critical night length
the number of hours of darkness that determines whether or not a given plant will flower
day-neutral plants
plants whose flowering cycle is not sensitive to periods of light and dark
dormancy
a period when an organism's growth or activity stops; helps plants survive freezing temperatures and the lack of liquid water
annuals
flower plants that complete a life cycle within one growing season; most have herbaceous stems
biennials
angiosperms that complete their life cycle in two years
perennials
most flower ever year; most have woody stems that live through the winter