semester 1 science

What does electricity in a circuit mean?

Electricity in a circuit refers to electrons moving through the wires.

What property does an electron have?

Electric charge

What happens in static electricity?

The electrons build up in one spot and can’t move

What is current electricity?

When the electrons flow through a pathway

What is current?

Current is a flow of charge.

What is the load in an electric circuit?

It is an energy converter (transducer)

Define the conducting path

The conducting path is a continuous uninterrupted route through which electrical current can flow. It connects all of the components of a circuit and is made of conductive metal.

What happens when the is a break in the conducting path?

It stops the current from flowing

What do we call a deliberate break in a conducting path?

A switch

Voltage is the amount…

Voltage is the amount of energy that is pushing electrons around a circuit

The amount of voltage used in each individual component of the circuit will…

Add up to the total voltage of the power supply

The voltage that is used up in each component is also known as…

The potential difference because it is the change in potential/stored energy of the electrons as they move through the component

What are insulators?

Materials that do not conduct electricity, e.g wool and palstic

Connecting wire

Carries charge

Single cell battery

Produces energy

Ammeter

Measures the current

Voltmeter

Measures voltage

Resistor

Uses up load/electricity

In a series circuit current is..

The same at all points in the circuit

In a series circuit adding more globes…

Means resistance increases so less current can flow in the circuit

The voltage of the supply must equal…

The sum of the voltages across the loads

In a parallel circuit the current…

The current splits between branches - each part gets a share depending on its resistance

In a parallel circuit voltage…

Stays the same across all components no matter how many branches there are

In a parallel circuit resistance…

Decreases as you add more branches

What does an ammeter measure electric current in?

In Amperes (A) or in one-thousandths of an ampere, which are called milliamperes

What is electrical resistance?

A measure of how difficult it is for electrons to flow through part of a circuit.

What is the method to calculate resistance?

R=V/I where v is the voltage drop in volts and I is the electrical current in amperes

What does ohms law state?

That the electric current in metallic conductors is proportional to the voltage drop across the conductor.

Ohmic devices have a…

A constant resistance and a linear Voltage drop (V) vs Current (A) graph.

Non ohmic devices do not have…

Non-ohmic devices do not have a constant resistance and have a non linear Voltage drop (V) vs Current (A) graph.

What is an abiotic factor?

A non - living component of the eco-system

What is a biotic factor?

A living organism

What is an environmental factor?

Anything that in an environment that can affect living organisms

What is an environmental condition?

The state of an environmental factor at a particular time or place

Interspecific

Occurs between two different species

Intraspecific

Occurs within members of the same species

Competition

Organisms with a similar niche within an ecosystem will compete where their needs overlap

Predation

In a predator - prey relationship, one species kills and eats other species

Parasitism

Parasite are organisms that live in or on a host, from which they obtain food, shelter and other requirements, although the host may be harmed in this interaction it is not usually killed.

Symbiotic

Close ongoing relationship between two organisms of different species. At least on of the two species benefit from the relationship.

Mutualism

A relationship between two organisms of different species in which they both benefit and in many cases the species can’t survive without one another.

Commensalism

A relationship between two organisms were one organism benefits but the other receives no benefit or harm.

Producer

Organisms that make their own food, also known as autotrophs

Consumers

Organisms that need to consume food to obtain their energy. Called heterotrophs.

What is a the fourth trophic level called?

A tertiary consumer

What does an energy pyramid indicate?

How much energy is available at each level in the food chain.

What does a biomass pyramid show?

The mass of organisms at each trophic level.

Only 10% of the energy available at each trophic level moves on to the next level. What happens to the other 90%?

It is progressively lost to the enviroment.

What is the photosynthetic equation?

Carbon dioxide + water —light energy/chlorophyll→ Glucose + oxygen + water

What is population density?

The number of individual organisms of a single species

What is the equation for population density?

Total population size/available habitat are or volume

What is carrying capacity?

The maximum population size of a species that a specific environment can sustain indefinitely with out degrading the ecosystem.

PNS

Contains nerves.

Axon terminal

The axon terminal is where the message is passed on to another cell, organ muscle

Dendrite

Dendrite collects information from a stimulus

Cell body

The cell body contains the nucleus and mitochondrion

CNS

Contains brain and spinal cord.

Axon

The axon transmits information from the dendrites to the axon terminal. This message is electrical (nerve impulse), it can only go one direction.

Myelin sheath

The Myelin sheath increases the speed that the message is sent down the axon

Sensory Neuron

Carries the impulse generated by the stimulus to the central nervous system. Located in the PNS

Inter neuron

Carries the impulse through the central nervous system. Location CNS

Motor neuron

Takes the impulse to effectors such as muscles or glands

Stimulus

A change in internal or external environment

Receptor

The part of the body that detects the change

Controller

The processing centre that decides if action is taken

Effector

A cell tissue or organ that responds to the controllers signal

Response

A designed change in function of a cell tissue or organ

Voluntary actions

Conscious decisions that require thought from the brain

Involuntary actions

Occur unconsciously and without thought which can make them super quick

Reflex actions

May involve only a few neurons and require no conscious thought

Cerebrum

Largest part of the brain (90%) volume. Controls - speech, decision making, cognitive function and voluntary actions.

Thalamus

In the centre of the brain, relays sensory information, regulates arousal, filters unnecessary sensory input

Hypothalamus

Small structure located under thalamus, links hormonal and nervous systems, regulates hormones.

Reticular formation

Arrangement of neuron clumps, connection to a network that runs from the hind brain to the forebrain, controls consciousness, motor control.

Pons

Pons acts as a bridge connecting the cerebellum and the forebrain, controls sleep and arousal, facial expressions, hearing

Medulla - Brain stem

Connects the brain to your spinal cord, Controls involuntary vital actions such as your breathing, blood pressure/heart rate, body temperature, coughing/sneezing, salivating

Cerebellum

Only takes up 10% of the brains volume but contains over half of the brains neurons. Controls posture, coordination, balance, movement.

Frontal lobe

Motor control and complex cognitive process, decision making, problem solving, reasoning, impulse control

Temporal lobe

Interpretation of sound, language comprehension, processing emotions, visual memory

Partial lobe

Sensory processing and spatial awareness, interpretation of touch, understanding numbers, shapes and space

Occipital Lobe

Processing visual information, perception and interpretation

Left hemisphere

Controls the right side of the body, specialised functions language processing and logic

Right hemisphere

Controls the left side of the body, specialised functions of the body are creativity and perception

Corpus callosum

A thick bridge of nerve fibres connecting the two hemispheres, Allows hemispheres to communicate

White matter

A result of Myelin coated axons of a neuron

Grey matter

Where complex processing occurs and where shorter neurons connect

Age (taste perception)

As we age our sense of taste can decline and we are less sensitive to the 5 tastes

Attention

Involves focusing our menta resources on certain information while blocking out irrelevant information

Bottom up processing

Perception that is built up from the sensory input. Bottom up processing helps you analyse different parts of a stimulus and build a meaningful understanding from them.

Chemoreceptors

Detect changes in chemical concentration

Context (taste perception)

The context in which food occurs can affect the taste

Cornea

The curved clear outer covering of your eye

Divided attention

Involves the process of simultaneously attending to two or more stimuli

Emotional state (taste perception)

Our emotional state can affect our taste, for example liking foods because of childhood nostalgia

Food culture (taste perception)

The attitudes, behaviours, customs and values around food with which we were raised can influence how we perceive the taste of other foods

Fovea

Point of central focus

Genetics (taste perception)

The genetic make up of an individual impacts the way they taste information. Genes can affect the number of taste buds we have and how sensitive they are

Iris

The coloured part of the eye that opens and closes the pupil to control the amount of light that enters the eye

Lens

A transparent curved object that bends light towards or away from a point called the focus

Mechanoreceptors

Detects change in touch, sound, motion and muscle movement