Mock Part One.

Question 1

Two symptoms of infection by Salmonella are vomiting and diarrhoea.
What causes these symptoms?

Answer 1

Toxins are secreted from the bacteria.

Question 2

Give two ways a person with a mild infection of Salmonella can help prevent the spread of the bacteria to other people.

Answer 2

Wash hands before preparing food

Isolate yourself

Question 3

What type of drug can the doctor prescribe to kill the bacteria?

Answer 3

Antibiotics.

Question 4

A person with AIDS may take longer than a healthy person to recover from a Salmonella infection.
Explain why.

Answer 4

The immune system is damaged.

White blood cells cannot kill bacteria.

Question 5

Suggest one way farmers could prevent the transmission of Salmonella from chickens to humans

Answer 5

Give chickens antibiotics.

Question 6

What measurement would the scientist need to take to calculate the area where no bacteria were growing?

Answer 6

The radius of the area where their is no bacteria present.

Question 7

Give one change to the investigation that would allow the scientist to check if the results are repeatable.

Answer 7

Repeat the investigation and see if the results are either consistent and similar.

Question 8

Suggest one other factor the restaurant owner should consider when choosing which cleaning liquid to use.

Answer 8

Whether the product is toxic.

Question 9

Give one other metabolic reaction in cells.

Answer 9

Respiration,

Question 10

During excersize the heart rate of smokers increases more than the heart rate of non-smokers - Design and investigation for this hypothesis.

Answer 10

You need to find two groups of people - non-smokers and smokers
• have at least five to ten people in each group or large groups
• get each person to do (jogging) exercise
•controlled variable ; - same number of people in each group or large groups - same gender - same level of activity / exercise - same age - no health issues / illnesses - same type of exercise - same time for exercise
• record heart rate for each person before and after exercise
• calculate increase in heart rate for each person after exercise • compare results for each group

Question 11

Name two substances transported in the blood plasma.

Answer 11

Lactic acid.

Water.

Question 12

Why having more red blood cells is an advantage to an athlete.

Answer 12

More haemoglobin so more oxygen can be transported.

For more aerobic respiration of the muscles.

Question 13

Which blood vessels carry deoxgenated blood?

Answer 13

Pulmonary artery.

Vena Cava.

Question 14

Which blood vessel carries blood into the right atrium?

Answer 14

B

Question 15

Compare artery structure with the vein.

Answer 15

Arteries dont have valves wheras veins do.
Arteries have a narrower lumen wheras veins have a wider lumen.
Arteries have a thicker layer of elastic tissue wheras veins have a thinner layer of elastic tissue.

Question 16

What condition is treated using an artificial pacemaker?

Answer 16

Arrythmia.

Question 17

Reasons why mouthpeice of an aphid has a high concentration of sugar after feeding.

Answer 17

Aphid has been feeding from the phloem.

Question 18

Explain how magnesium deficiency causes yellow leaves and stunted growth.

Answer 18

yellow leaves due to lack of chlorophyll
therefore less light absorbed by chlorophyll
therefore lower rate of photosynthesis
therefore plant makes less glucose
therefore plant converts less glucose into protein for growth, so growth is stunted

Question 19

Describe how scientists use the protein to produce PVY monoclonal antibody?

Answer 19

inject the protein into a mouse
combine lymphocytes with tumour cells to make hybridoma cells.
find a hybridoma which makes a monoclonal antibody specific to PVY
the scientist should clone the hybridoma to produce many cells to make the antibody

Question 20

Molecules are genes made from?

Answer 20

DNA.

Question 21

What is the function of cell membrane?

Answer 21

controls the movement of substances in and out of cell

Question 22

Why do people with asthma find it hard to breathe?

Answer 22

fewer (digestive) enzymes enter small intestine • (so) enzymes break down / digest less food • (therefore) less absorption of nutrients • (so) less glucose can enter the blood(stream) • (so) less (glucose) available for respiration • (less absorption of nutrients so) fewer amino acids can enter the blood(stream) • (so) less protein is made (for growth) ignore ref to bile

less oxygen enters blood(stream) / reaches cells / organs / tissues (ignore body / lungs) • (so) less (oxygen) available for (aerobic) respiration • (so) less energy released / available (for growth)

Question 23

How stem cells are used to make a lung.

Answer 23

take stem cells from patient (bone marrow / skin)
remove CF gene
create embryo using these stem cells
remove stem cells (from embryo) and / allow them to differentiate into lung (cells)

Question 24

Why do peopple disagree with stem cells?

Answer 24

Loss of potential human life.

Question 25

How hould you test milk for carbs?

Answer 25

• Biuret reagent tests for protein
• add Biuret reagent to milk
• solution will turn (from blue) to lilac if positive
• iodine solution tests for starch (ignore iodine unqualified)
• add iodine solution to milk
• solution will turn (from orange / brown) to blue / black if positive
• Benedict’s reagent tests for sugars
• add Benedict’s reagent to milk and boil / heat (allow any temperature above 60 °C)
• solution will turn (from blue) to (brick) red / brown / orange / yellow / green if positive

Question 26

Why indicator becomes colourless?

Answer 26

lipase breaks down fat into fatty acids (and glycerol)
(and) fatty acids lower the pH
(and when) fatty acids cause the pH to be below 10 (the indicator becomes colourless

Question 27

Why are pH inaccurate?

Answer 27

Colour is based on opinion.