BIO ( 5,6 )
Germ-line
WHAT IS VIRULENCE?
The ability of a pathogen to infect or damage a host
WHAT ARE COILS IN A TRANSFORMER LINKED BY?
ELECTROMAGNETIC INDUCTION OR FLUX LINKAGE
WHAT IS AN ABSORPTION SPECTRA?
The wavelengths of light absorbed by a particular material when light passes through it
WHAT IS THE PH OF BLEACH?
13
HOW DO FROGS REPRODUCE? (FERTILISATION, TYPE OF REPRODUCTION)
Sexually
External fertilisation
WHAT IS BACTERIOSTATIC?
An antibiotic that hinders bacterial growth - doesn't kill bacteria
WHAT FACTORS DOES THE MAGNETIC FORCE ON A MOVING CHARGE DEPEND ON? - NAME AT LEAST 2
CHARGE, VELOCITY, MAGNETIC FIELD STRENGTH
WHAT ARE MESONS MADE OF?
WHAT IS LE CHATELIER'S PRINCIPLE?
WHY DO SOME IDENTICAL TWINS LOOK DIFFERENT?
Phenotype - gene expression
OR
Environmental differences
OR
Mutations in DNA replication / PPS
WHAT ARE THE STEPS IN A FEEDBACK LOOP?
Homeostasis > Stimulus > Receptor > Control centre > Effector > Equilibrium > Homeostasis
WHY MUST AN OBJECT REACH ESCAPE VELOCITY TO LEAVE A PLANET'S GRAVITATIONAL FIELD WITHOUT RETURNING?
ESCAPE VELOCITY = MINIMUM INITIAL SPEED NEEDED TO ESCAPE A GRAVITATIONAL FIELD
The object must have enough kinetic energy to overcome the gravitational potential energy holding it to the planet. At escape velocity, the object can move infinitely far away with zero final speed.
NAME LIMITATIONS OF NEWTON'S MODEL OF LIGHT
Colours of light, interference, partial reflection and refraction
WHAT IS KEQ?
The ratio of the concentration of products to reactants
WHAT DIRECTION DOES DNA MOVE IN GEL ELECTROPHORESIS?
Towards the positive electrode
WHAT IS KOCH'S FOURTH POSTULATE?
When the isolated microorganism is inoculated into a healthy host, the new host must develop the same disease as the first
WHEN AN OBJECT IS UNDERGOING CIRCULAR MOTION, WHAT IS LINEAR VELOCITY AND WHAT DOES IT REPRESENT?
Linear velocity = speed of the object along the circumference of object
It represents how quickly the object travels around the circular path
WHY DOES BETA DECAY CHANGE THE IDENTITY OF AN ATOM BUT NOT ITS MASS NUMBER?
A neutron changes into a proton and emits a β⁻ particle.
The number of nucleons stays the same → mass number unchanged.
The number of protons increases by 1 → atomic number increases by 1, changing the element.
WHAT IS THE FUNCTIONAL GROUP OF AN ALCOHOL
-OH
WHAT IS ONE EXAMPLE OF A CHEMICAL MUTAGEN?
Reactive oxygen species - e.g. Hydrogen peroxide
OR
Benzene
OR
Intercalanting agents - e.g. Ethidium
OR
Alkylating agents - e.g. Nitrosamines (Tobacco smoke)
OR
BAse analogues - e.g. 5-bromouracil
WHAT ARE PROTO-ONCOGENES?
Normal genes which stimulate cell growth and mitosis - cause cancer when mutated or overexpressed
WHY DOES AN ELECTRIC MOTOR DRAW MORE CURRENT WHEN STARTING THAT WHEN OPERATING AT ITS NORMAL SPEED? - EXPLAIN USING EMF
Start up = little/no back EMF, high current
Motor speeds up = back EMF increases, opposes the applied EMF, reduces current
Operating speed = back EMF and applied EMF are balanced
WHAT KEY OBSERVATIONS OF THE PHOTOELECTRIC EFFECT CHALLENGED THE WAVE MODEL OF LIGHT?
Minimum frequency needed, regardless of intensity
Intensity -> number of electrons emitted
No time delay in emission
Threshold frequency varies between materials
WHAT IS AN ISOMER?
Molecules that share the same chemical formula but different structural arrangements