Science, Sem 2 (Yr 7) Flashcards
Levers: what are they and how do you calculate the M.A
- M.A = load~divided by~effort
- This means that a lever has greater M.A when the distance from the fulcrum to effort is LONGER than the distances from fulcrum to load.
- Levers are simple machines
- Latin= to make lighter
Inclined Planes: what are they and how do you find the M.A
- M.A= length of slope~divided by~height of slope
- The M.A of a ramp is that there is less effort to move an object up sloping surface than to lift to full height.
Pulleys: what are they/ how to they work
- Pulleys are a wheel with a groove around it into which a rope of chain can move.
- To increase force applied, more than one pulley must be added
- Works by = turning point of lever (fulcrum) which everything “rotates” around
Single Pulley/ double pulley and what it does
- A single pulley changes the direction but not size of the effort required to lift the load.
- Two pulleys halves the size of the effort required, providing a M.A of 2
- In this case the force is applied over a greater distance
Gears: how to find the gear ratio
- The gear ratio of two gears is calculated by dividing the number of teeth on the driver gear, by the number of teeth on the driven gear.
Wheels and Axels: what is it
- A lever that rotates (e.g doorknob)
- Used to make things move faster
- Application= pair of wheel and axels join together by a belt
Bottle opener/ tennis racquet
2nd class lever ELF 3rd class lever LEF
Biology Meaning
Study of living things
- Biologist is a scientist who studies organisms
Mrs Gren
M-ovememt, all living things (…)move in someway
R-espiration, … need energy so carry out respiration
S-ensivity, … respond to what happens in environment
G-rowth, … grow
R-eproduction, … have way of passing genetic material (DNA) to next generation
E-xcretion, … must eliminate waste from bodies
N-utrition, … must take in nutrients (food/eat)
Classification Definition
The process of putting things into groups. A skill needed in many areas
E.g supermarkets-they classify their goods according to similarities
DVD-classify by genre
How do scientists classify
They classify things with similar features so they can compare. Also to identify organisms.
Taxonomy/taxonomists
Taxonomy- science of groups\names of organisms
Taxonomist- scientist who specialise in creating groups\names to put organisms into
How do taxonomists classify
By similarities and differences in structural features (using keys)
Also by using DNA (genetics) to classify in proteins
What are the 7 Hierarchical system of classification
-kingdoms
-phylum
-class
-order
-family
-genus
-species.
(The higher on the list the, number of organisms increases)
(The lower on the list the, organisms become more alike)
5 kingdoms
Animal Plantae Fungi Protista Monera
Species definition
Group of organisms closely resemble each other, can interbreed
Invertebrates definition
Animal without backbone-95% of all animals
Definition of adaptations
Characteristics that help organisms survive
Enable animals to protect, camouflage, survive weather, move, eat , breath, reproduce
Enable plants to protect, oxygen&carbon dioxide,water,light
Structural adaptations
Enable: (view screenshots)
Camouflage, sting, poison
E.g stick insect, porcupine
Physiological adaptations
Enable: (view screenshots)
Sweat, tanning, venom, poison
E.g snake
Behavioural adaptations
Enables: (view screenshots)
Bathing, hibernation
E.g hedge hog, desert mouse
Endo/Exo/No skeleton
Exo skeleton- outside body. E.g starfish, seahorse, snail
Endo skeleton- inside body. E.g dog, human
No skeleton- no skeleton. E.g jellyfish, slug
Class-Mamalia
Defined by mammal glands, produce milk, hair, most born not hatched, fertilisation internal
Types of mammals
Placentals- longer pregnancy, joined to mothers uterus, e.g squirrel
Monotremes- only mammal that has eggs, e.g echidna, platypus
Marsupial- pouch for young, pouch called marsupium, e.g kanga, wombats, koalas
