Super Six Markers Paper 1

Question 1

Bodies response to infection

Answer 1

1. The pathogen enters the blood stream and multiplies
   2.A realease of toxins and infection of body cells cause symptoms in the patient
2. Phagocytes engulf the pathogen
   4.b lymphocytes recognise the antigens and start to produce specific antibodies
   5.Antibodies cause agglutination of pathogens
3. Phagocytes engulf and digest agglutinated pathogens
4. The body retains antibodies specific to the disease as well as memory cells

Question 2

Vaccinations

Answer 2

Vaccines are used to induce immunity to infectious disease
Vaccine contains harmless versions of pathogens
Once in the blood stream the body issues immune response
Lymphocytes produce antibodies specific to antigen encountered
Memory cells and antibodies are produced and remain circulating in blood stream
If antigen is encountered again antibodies are produced much faster
Due to rapid nature of response antigen is unable to cause disease and patient is immune

Question 3

The pathway of human nervous system

Answer 3

A stimulus is received by a sensory neurone
Receptor produces electrical impulse
Impulse travels along sensory neuron to CNS
In CNS impulse is passed onto a relay neuron
The relay neurone links to the motor neurone where it travels until
It reaches the effector
The effector that is either a muscle of gland carries out a response

Question 4

Reflex arc pain

Answer 4

Pin is stepped on (stimulus) is detected by pain receptor in skin
Sensory neurone sends electrical impulse to the spinal chord
An electrical impulse is passed to relay neurone
Relay neurone synapses with a motor neurone
Motor neurone carries impulse to muscle in leg (effector)
When stimulated muscle will contract and pull foot away (response)

Question 5

DNA extraction

Answer 5

Mash fruit and mix in beaker containing detergent
Detergent breaks down cell membrane causing fruit cells to release there dna
Filter mixture into a test tube this removes debris
Gently add some ice cold ethanol to the filtrate by pouring the ethanol slowly down the side of the test tube
This causes dna to precipititate as dna is insoluble in ethanol

Question 6

Genetic engineering

Answer 6

Remove double stranded dna from cell
Cut desired gene out of dna using restriction enzyme to leave single stranded sticky ends
Remove a plasmid from bacteria
Cut plasmid open using same restriction enzyme to produce complementary sticky ends
Insert gene into plasmid using dna ligase - which allow h bonds to form between bases
Insert recombinant plasmid into bacteria using gene gun
Leave to divide by binary fission