science keywords Flashcards
natural science
the study of the natural world
two types of natural sciences
physical science and biological science
physical science
deals with inanimate (non living things)
subjects of physical science
physics, chemistry, astronomy, geology and computer science
biological science
deals with living things
two types of biological science
botany and zoology
botany
the study of plants
zoology
the study of animals
hypothesis
a proposed explanation of why certain events take place
theory
is an explanation of observations and is bases on hypothesis, laws and facts
scientific law
a description of observed occurrences and is based on repeated experiments
primary data
collected by the researcher themselves
secondary data
data that has not been collected by the scientist themselves
cell
smallest working unit of a living thing
organism
the name given to any living thing. for example, both plants and animals are organisms
multicellular
organisms made up of 2 or more cells
unicellular
organisms made up of only one cell
tissue
a group of cells of the same type working together to do a particular job
organ
a group of tissues working together to carry out a function
system
a number of organs working together to carry out a function
the seven characteristics of life
movement
reproduction
growth
response
respiration
excretion
nutrition
animal cell
has mitochondria, cytoplasm, cell membrane, nucleus, ribosome
plant cell
has mitochondria, cytoplasm, cell membrane, nucleus, ribosome, cell wall, chloroplast and large vacuole
parallex error
make sure when you are taking a measurement that you eye is directly over the number on the scale so that you take and accurate reading
oesophagus
carries food from the mouth to the stomach
stomach
churns food
adds hydrochloric acid to food
chemically digests food
has villi for absorbtion
pancreas
makes enzymes to digest food
liver
produces bile to aid in fat digestion
gall bladder
stores bile until it is needed in the small intestine
small intestine
7 meters long
digests food and absorbs food into the bloodstream
large intestine
stores undigested food for egestion
made up of 2 parts:
colon
rectum
rectum
stores faces for egestion
colon
absorbs water from food into the blood
anus
allows faeces to pass from the body
appendix
no longer has a function
digest
to break down large food particles into smaller soluble particles
mechanical digestion
physically breaking down food. for example, chewing
chemical digestion
breaks down food chemically. example, enzymes in the salivary glands
incisors
cuts and slices food
canines
grips and tears food
molars
chews and grinds food
premolars
chew and grind food
wisdom teeth
chew and grind food
often removed as they are not needed
density
how much matter is inside the same volume. eg, 1m3 of styrofoam is less dense than 1m3 of water
melting point
the temperature at which a solid changes to a liquid
boiling point
the temperature at which a liquid changes to a gas
freezing point
the point where a liquid turns back into a solid
condensation
when a gas changes into a liquid
molecule
made up of 1 or more atom. they can be the same or different atoms
atoms
smallest part of a chemical element that can exist
element
substance that only contains one type of atom
compound
a substance that is made up of 2 or more different elements that are chemically combined (joined together). compounds contain 2 or more different types of atoms joined together by chemical bonds
element
substance that only contains one type of atom
mixture
two or more different substances mingled with each other but not chemically combined
physical change
when the atoms form in a new way to give us a mixture by do not create a new substance
chemical change
when atoms arrange in a different way to give us a new substance called a compound
evaporation
the changing of a liquid to gas at the surface of the liquid
