Food chains
Ecological relationships and adaptions
Safety in wiring
Simple circuits and measurements
Tricky will make you think
100
Compare an autotroph and heterotroph
Autotrophs are producers they make their own food, heterotrophs are consumers they eat below them in a food chain
100
What is the term that both organisms gain from
what is the term when one organism gains and the other has no impact
mutualism
commensalism
100
Which is reusable a fuse or a circuit breaker?
circuit breaker
100
What measures current? What are the units?
What measures Voltage? What are the units?
Ammeter - amps (A)
Voltmeter - voltage (V)
100
How does high voltage assist in the reduction of energy losses in transmission lines/power lines?
All wires have a set resistance - so the higher the voltage the less the current. Less current, less heat
200
Is this a pyramid of numbers, energy or biomass
Pyramid of energy
200
Suggest a reason for the multiple cycles in this graph
seasons - such as weather
Mating cycles
200
2 characteristics of a fuse are:
high resistance
Low melting point
200
R1 and R2 have the same values. What is the voltage on the meter?
6V -
battery is 12v the two components equally share the source voltage 12/2 =6
200
Will the voltmeters all record the same or different? Why?
Should be the same as wires and ammeters have minimal resistance
300
List 3 ways energy is lost in a food chain
heat due to respiration
not all of the organism in the trophic level below was consumed ie bones, hair/fur, internal organs
The organism uses up energy in its daily life
Some energy consumed is excreted
300
why does the prey cycle lead and the predator cycle lag? Suggest 2 reasons
there must be enough food supply (prey) to sustain the predator
energy losses in food chains it is typical that only 10% of energy is passed to the next trophic level
predators tend to be larger than prey and need a greater energy intake
300
If a 7A appliance is connected to a power point, the factory wiring is rated to 10A (meaning the wires in the walls to the power points won't be degraded until the current goes above 10A), which of the following fuse or circuit breaker ratings would be best to protect the appliance?
7A, 9A, 11A, 15 A
9A - just a little higher than the applicance.
7A is no good its likely to blow every time the appliance is in use.
300
What is the value of the resistor?
V=IR
R=V/I
R=10/2
R = 5 ohms
300
If the variable resistor increased its length - what would happen the lamp and ammeter?
Increase in length, increases resistance in the circuit. Lamp would become dimmer, current would reduce
400
what are the word and chemical equations for photosynthesis?
400
What does SPB mean in terms of adaptations
Structural
Physiological
Behavioral
400
Often the earth pin on a 3 pin plug is bigger and thicker - why?
Note this plug is not from Australia but shows the larger earth pin
remember the three things that effect resistance (length, diameter and type of material)
the thicker metal pin is similar to a larger diameter, it will have less resistance, so it can ëarth" any current more effectively
**often unwanted current
400
If all lamps have the same resistance and the current in one lamp is 2.5A what is the current in the ammeter shown
7.5A
The ammeter is located where 3 circuits flow
2.5+2.5+2.5
400
Would all these lamps glow with the same brilliance if they were all the same kind?
the one on the right would have more current through it
500
A student carried out a practical activity - suggest the expected results if they covered pond weed in different coloured cellophane - their IV was these colours of cellophane - clear, yellow, green, red, dark blue
The colored cellophane is letting light of only one color pass through. Plants absorb light and convert it to chemical energy, which they use for growth. Plants don't absorb all colors equally, though, and which color of light they absorb the most depends on which light-absorbing pigments the plant has.
500
Give an example of adaptations made by desert animals in Australia
nocturnal to avoid the heat (Behavioral)
slow the metabolism down (phsyiological) to conserve energy
Coloured to match their environment (structural)
Length of kidney loop of henle (structural) this is to absorb as much water from urine as possible
Plants have spikes not leaves (structural) to reduce water loss
500
what's going on? what material is needed for this to work a conductor on insulator?
static electricity
the balloon has been rubbed and it has gained electrons, making it MORE negative than the hair.
The hair is now attracted to the balloon
500
What is the unknown voltage drop?
5V
9V-4V = 5V