Higher and Triple content

Question 1

What are the steps of growing bacteria in the lab. - 5 marks

Answer 1

-Sterilize the innoculating loop(which is used to transfer microorganisms) by heating it using a bunsen burner.
-Dip the sterilized loop in the bacteria zigzag it across the surface of the agar
-Place the lid on and fix it with tape to prevent microorganisms from the air contaminating the culture
-Do not seal all the way around the edge as oxygen is needed get into the dish
-Store the petri dish upsidedown at a low temperature to prevent harmful bacteria from growing

Question 2

What are the symptoms of disease in plants?(any 3 of 5) - 3 marks

Answer 2

-stunted growth
-spots on leaves
-areas of decay or rotting
-discoloration
-physical pests

Question 3

What physical barriers do plants have that reduce the invasion of pathogens?- 2 marks

Answer 3

-Cellulose cell wall-strengthen plant cells which help to resist invasion by microorganisms
-Tough waxy cuticle - acts as a barrier to the entry of pathogens

Question 4

How are monoclonal antibodies created?

Answer 4

-mouse lymphocytes make specfic antibodies but do not divide
-tumour cells divide rapidly but do not make these antibodies
-these are joined together to form a hybridoma cell
-these cells are then clones
-monoclonal antibodies are separated,purified,and the can be used

Question 5

What are the advantages of monoclonal antibodies?

Answer 5

• they bind to specific disease and doesnt not affect healthy cells
  -it could be used to treat a wind range of conditions

Question 6

What are the disadvantages of monoclonal antibodies?

Answer 6

• there are many side effects due to the hybridoma cells

Question 7

How does oxygen debt work?

Answer 7

-lactic acid is produced during anaerobic respiration
-this lacric acid need to be comverted back to glucose in the liver but the process needs water to be done
-the amount of oxygen needed to convert the lactic acid to glucose is oxygen debt
- this is why after a race your heart rate and breathing rate will increase in order to supple the body with enough oxygen

Question 8

What is the role of the liver?

Answer 8

-Detoxifying poisonous substances (such as ethanol from alchoholic drinks)
-passes the breakdown products to the blood so it can be excreted in the urine

Question 9

What is the function of the cerebral cortex?

Answer 9

-conciousness,intelligence,memory,language

Question 10

What is the function of the cerebellem?

Answer 10

-coordintaing muscular activity and balance

Question 11

What is the function of the medulla?

Answer 11

-unconscious activities such as the heartbeat,breathing

Question 12

How does glucagon control the blood hormone levels?

Answer 12

• the pancreas secretes glucagon
  -glucagon makes the liver break down glycogen converting it back to glucose
  -the stored glucose is then transported back to the blood
  -this is done using negative feedback

Question 13

How does ADH work?

Answer 13

-adh is secreted through the pituitary gland to maintain the water in the blood
-receptor cells detect the concentration of solutes in the blood
- if the concentration is too high lots of adh will be released into the blood
-this affects the kidney tubles so that it absorbs more water