Cite

Question 1

State how bacteria multiply

Answer 1

Simple cell division/binary fission

Question 2

Describe how to prepare uncontaminated bacterial culture for investigating the action of disinfectants and antibiotics

Answer 2

.petri dishes and culture media must be sterilised before use
.inoculating loops must be sterilised by passing through a flame
.the lid of the petri dish is secured with tape and placed upside down
.in school labs, cultures should be incubated at 25°c

Question 3

Define monoclonal antibodies

Answer 3

Produced from a single clone of cells. The antibodies are specific to the binding site on one protein antigen and so are able to target a specific chemical or specific cells in the body.

Question 4

Give 4 uses of monoclonal antibodies

Answer 4

. Diagnosis e.g pregnancy tests
.lab tests to test for chemicals in blood or detect pathogens
.research to locate specific molecules in a cell or tissue by binding a fluorescent dye to them
.treating diseases e.g cancer

Question 5

State the reason for the low use of monoclonal antibodies

Answer 5

Monoclonal antibodies create more sideeffects than expected. They are not yet as widely used as everyone hoped when first developed

Question 6

Give 6 ways of detecting the presence of plant diseases

Answer 6

.stunted growth
.spots on leaves
.areas of decay
.Malformed stems or leaves
.discolouration
.presence of pests

Question 7

State the effects of ion deficiencies in plants

Answer 7

.Stunted growth caused by nitrate deficiency(needed for protein synthesis)
.chlorosis causex by magnesium deficiency (needed to produce chlorophyll)

Question 8

Describe the physical defence responses to plant pathogens

Answer 8

Cellulose in cell walls,tough waxy cuticle on leaves, bark layers of dead cells around stems

Question 9

Describe the physical defence responses to plant pathogens

Answer 9

Cellulose in cell walls,tough waxy cuticle on leaves, bark layers of dead cells around stems

Question 10

Describe the chemical defences to plant pathogens

Answer 10

Antibacterial chemicals, poisons to deter herbivores

Question 11

Describe the mechanical defences to plant pathogens

Answer 11

Thorns and hairs to determine animals, leaves which droop or curl when touched, mimicry to trick animals

Question 12

State the position and function of the cerebral cortex

Answer 12

Front of brain. Controls learning and memory

Question 13

State the position and function of the cerebellum

Answer 13

Back of brain. Controls movement

Question 14

State the position and function of the medulla

Answer 14

Lower front. Controls unconscious processes e.g breathing and heart beat

Question 15

Describe how the eye focuses on a near object

Answer 15

The ciliary muscles contract. The suspensory ligaments loosen. The lens thickens and refracts light strongly

Question 16

Describe how the eye focuses on a distant object

Answer 16

The ciliary muscles relax. The suspensory ligaments are pulled tight. The lens is pulled thin and only slightly refracts light rays

Question 17

Describe the body response to high temperature

Answer 17

Vasodilation and sweat is produced to transfer energy from the skin to the environment

Question 18

Describe the response to low temperature

Answer 18

Blood vessels constrict vasoconstriction, sweating stops and skeletal muscles contract shiver

Question 19

Describe how excess protein is removed from the body