Corrections

Question 1

What is the effect of distance from the light in the elodea practical

Answer 1

As the light is moved closer the light intensity increases so rate of photosynthesis increases so more bubbles are produced

Question 2

Why is a beaker of water placed in front of the elodea in the practical

Answer 2

To absorb heat so the temperature of the elodea remains constant

Question 3

In the elodea practical how could the experiment be made more accurate

Answer 3

Collect gas instead of counting bubbles

Question 4

What is a double circulatory system

Answer 4

When blood passes through two systems; the systemic system and the pulmonary system.

Question 5

What is the valve in the left atrium to ventricle

Answer 5

bicuspid

Question 6

What is the valve in the right atrium to ventricle

Answer 6

tricuspid

Question 7

What do the semi lunar valves do

Answer 7

• open when the heart contracts
• close when the heart relaxes
• prevent back flow of blood

Question 8

Effects of exercise on the heart

Answer 8

The heart is a muscle. Exercise makes the heart more muscular.

Question 9

Why do sports scientists measure oxygen and carbon dioxide levels

Answer 9

To more accurately measure aerobic respiration

Question 10

Effects of reduced oxygen levels on plants (4)

Answer 10

• less aerobic respiration
• less ATP (energy)
• less active transport (mineral uptake)
• nutrient deficiencies

Question 11

Effects of phosphorus deficiency

Answer 11

Poor root growth

Question 12

Effects of potassium deficiency

Answer 12

Yellowing of the leaves

Question 13

Effects of nitrate deficiency

Answer 13

Poor plant growth and repair

Question 14

Why do roots increase the rate of transpiration

Answer 14

larger surface area for water absorption

Question 15

2 functions of the small intestine

Answer 15

• absorb nutrients
• digestion of food molecules

Question 16

2 ways the small intestine is adapted to its functions

Answer 16

• produces enzymes for digestion
• has a large surface area (villi) for absorption of nutrients

Question 17

are digested food molecules insoluble or soluble

Answer 17

soluble

Question 18

is protein soluble

Answer 18

no

Question 19

are amino acids soluble

Answer 19

yes

Question 20

How can an unbalanced diet and lack of exercise lead to atheroma (2)

Answer 20

• too much fat in diet
• lack of exercise means excess fat is not used as energy

Question 21

How can atheroma lead to heart attack

Answer 21

• atheroma blocks the coronary arteries
• this prevents oxygen from reaching the heart muscle

Question 22

What are the hairs in ciliated epithelial cells called

Answer 22

cilia

Question 23

What may you find in the mucus of a smoker (3)

Answer 23

• tar
• dust
• bacteria

Question 24

What enzyme breaks down urea to ammonia

Answer 24

urease

Question 25

what changes ammonia to nitrates

Answer 25

Decomposers in the soil such as bacteria

Question 26

What do plants use nitrates for

Answer 26

to make protein

Question 27

how is protein transferred to animals in the nitrate cycle

Answer 27

plants are eaten by animals. Plant protein is changed to animal protein.

Question 28

How would action of platelets in coronary arteries be a problem (2)

Answer 28

They cause clotting. This reduces blood flow to heart muscle.

Question 29

Is protease a protein

Answer 29

Yes

Question 30

Why are the walls of the ventricles thicker than the atria

Answer 30

Atria have thinner walls as they only have to pump blood to the ventricles

Question 31

Why is the pressure between the pulmonary vein and artery different

Answer 31

The pressure drops as it passes through the lungs so it is higher in the pulmonary artery and lower in the pulmonary vein

Question 32

Why is the blood pressure in the aorta and pulmonary artery different (2)

Answer 32

- The left ventricle has a thicker wall than the right atrium - Left ventricle produces a higher pressure as it has to pump blood a larger distance (around the body)

Question 33

Why does our blood have to return to the heart before it is sent to other organs of the body

Answer 33

Blood pressure is not high enough so it returns to the heart to be pumped at high blood pressure

Question 34

Limitation of heating food under water to test its energy content experiment

Answer 34

Not all the energy goes into the water. Some energy is lost to the environment.

Question 35

what nutrient makes up most of the carbohydrates in pasta

Answer 35

starch

Question 36

what typically happens to the size of organisms and number as the trophic levels increase

Answer 36

size of the organisms increases and their numbers decrease

Question 37

Why can skimmed milk not be used in a lipase experiment

Answer 37

it does not contain enough fat

Question 38

function of the focus adjustors

Answer 38

to bring object into focus

Question 38

name one group of industrial wastes

Answer 38

heavy metals

Question 39

What does bile do to pH

Answer 39

makes pH more alkaline in the small intestine so that there is optimum pH for lipase

Question 40

To ways to alter diet to lower BMI

Answer 40

- reduce fat intake - reduce carbohydrate

Question 41

explain how oxygen production can be used as a measure of the rate of photosynthesis

Answer 41

- photosynthesis produces oxygen - If the production of oxygen increases - the rate of photosynthesis is increasing

Question 42

why does heart rate remain high after exercise

Answer 42

More oxygen can get to cells, quicker

Question 43

explain advantage of increased number of red blood cells athletes

Answer 43

- more haemoglobin - more oxygen carried by the blood - more aerobic respiratio

Question 44

Two possible sources of nitrate pollution in streams

Answer 44

- fertiliser - sewage

Question 45

How could an experiment on leaves with sodium hydroxide in one container and nothing in the other be improved

Answer 45

empty container should include water so that the volume in each flask is equal

Question 46

why would a plant be kept in the dark before starch testing

Answer 46

- to remove the starch - to show that photosynthesis took place during the experiment

Question 47

a pyramid of numbers has a small producer bar and a pyramid of biomass has a large producer bar, what does this show

Answer 47

- the pyramid of numbers show there is a small number of producers - the pyramid of biomass shows there is a large mass of producers

Question 48

one way energy is lost between trophic levels

Answer 48

ejested waste

Question 49

what pass through pores in a semi permeable membrane

Answer 49

MOLECULES

Question 50

what do phagocyte nucleus' look like

Answer 50

squiggly (bunch ob blobs joined together)

Question 51

what do lymphocytes nucleus' look like

Answer 51

circular (more regular)

Question 52

why may a person with a high body mass not be obese

Answer 52

They may not be obese just very tall