Past Paper Q Flashcards
A person was in an accident and their memory is affected.
Which part of the brain is most likely to have been injured?
Cerebrum
What does short sightedness do
Let’s you see close thing but not far away things
Chronic venous insufficiency (CVI) is a condition caused by faulty valves found in some
blood vessels in the legs.
Describe how CVI will affect the person’s blood circulation.
Suggest one symptom of this condition.
Blood will back flow and collect in veinss causing irritation, swelling and itchiness
Give one factor, other than lack of water intake, that could cause a person to have
concentrated urine
Lots of salt in diet
Nephritis is a condition where part of the kidney tubule becomes inflamed. The result of this
is that proteins can enter the tubule and pass out in the urine.
Describe a test that could be used to determine if a patient has nephritis.
Use buries solution
-> blue to purple indicates protein presence
Hormones are part of the endocrine system.
Describe two differences between the endocrine system and the nervous system.
Endocrine system uses hormones, whereas nervous system uses nervous impulses
Endocrine uses bloodstream to travel, nervous system uses neurones and nerves
Why does the number of people with type two diabetes increase as it reaches 2016 but then decrease slightly
-> more people, have poorer diets
-> more sugar in diets
-> however more awareness meaning the number is decreasing
Scientists researching how mitochondria produce ATP came up with a theory.
Their theory said:
• Hydrogen ions are transported into the space between the two membranes surrounding
the mitochondria, shown in Fig. 25.1.
• The ions become concentrated in this space.
• The ions diffuse back into the mitochondria making ATP.
To test this theory the scientists removed the outer membrane of the mitochondria
The result of their experiment showed that less ATP is formed.
Why was their theory correct
-> ions cannot build up
-> cannot diffuse back into mitochondria
What is the purpose of the water beaker above the Potometer
To reset the gas bubble to the start of the scale
Polymenorrhea is a condition which affects the menstrual cycle.
Symptoms of the condition include the time between ovulation and the next period being shorter
than usual.
What hormone could treat this condition ans why
Progesterone
Maintains uterine lining
Light is one environmental factor that affects plants.
Explain how increasing the temperature from 15 °C to 40 °C can affect plants.
-> increased rate of biological processes such as photosynthesis or respiration
-> this is beacause particles involved in these processes gain ke due to increased temperature meaning that the reaction collisions are m or frequent
-> enzyme substrate catalysed reactions also speed up, as the collisions happen quicker and the reaction is catalysed. If the temperature is increased by too much then the enzymes may denature
Explain how guard cells change shape to open stomata.
(4 marks)
-> guard cells photosynthesis meaning they produce their own sugar
-> guard cells are more concentrated and havw a higher WP than epidermal cells
-> meaning water moves into guard cells via osmosis from an area of High WP to low WP
-> the guard cell swells and becomes turgid
-> outer wall of guard cell bends, but inner wall is much thicker meaning it only bends slightly
-> stomata opens depending on turgidity of guard cell.
Explain why homeostasis is important for metabolism in humans.
-> it allows (metabolic) reactions to happen at appropriate rates
-> allows optimum temperature and pH for enzyme controlled reactions
Give one way that the structure of blood vessels allows them to change blood flow in the
skin.
Elastic walls help the blood vessel to widen to allow more blood to flow through them
Explain three changes caused by adrenaline prepare muscles for exercise.
-> high blood pressure so more blood flow to the muscles
-> glucagon produced in order to break down glycogen into glucose So that the muscles can use it
-> increased breathing rate for increased oxygen intake to provide muscles with more oxygen
Which tissue in the wall of the heart contracts to pump the blood?
Cardiac muscle
Explain why a person why is dehydrated running a marathon has higher temperature and heart rate than someone who is good hydrated
-> muscles generate heat during excersise
-> heart rate increases in both people to supply muscles
-> however, dehydrated person has a higher body temperature beacause the lack of water means less sweat is prodieces
-> the dehydrated persons body cannot cool itself down causing the body temperature to be much higher than a regularly hydrated person
-> the lack of water also produces a drop in blood volume, meaning heart works harder to compensate pumping blood meaning heart rate increases
Suggest what an athlete could do in advance to minimise the effect of the challenges
during a desert marathon.
-> drink lots of water before the race
-> increase exposure to heat when training
Identify three problems with using colours to estimate theconcentration of glucose in a food.
(Benedict’s solution)
-> glucose may not be the only sugar present in the food
-> different people interpret different colours differently
-> colour of food could also affect what colour the solution looks
What does the S stage represent in cell cycle
DNA replication (synthesis)
What does the m stage represent in cell cycle
Cell division (mitosis)
Explain how the structure of DNA determines the type of protein made.
DNA determines sequence of amino acids.
Order of bases in DNA determines type of protein made
