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Edexcel igcse biology 1B

Hi how did everyone find the exam, there were a couple harder questions but in general I reckon I did well. Willing to discuss if anyone wants?
My responses and all the questions

I know someone who memorised all the questions. If anyone spots any pontential errors please do give me a shout!

Q1: food web (4 marks; 2MCQs, drawing food chain),

Q2: substances absorbed from the blood by animal what are they and why are they absorbed (4 marks),

glucose - gain energy

urea and excretory gasses - removed from human body?

Q3 transfers pathogens why are pathogens transferred to another person by mosquito (2marks)

blood taken in by mosquito BUT it may take in pathogen/disease causing microorganism

Pathogen inside blood of mosquito or on it

Mosquito moves to the second organism, inserts nose, may inject pathogen in blood stream

Q4 calculating magnification correct (2 marks),

that was correct

Q5: effect of changing light intensity on pondweed's rate of photosynthesis,

increasing light intensity /\ photosynthesis

Q6: fill in the blanks for yoghurt production (7 marks)

think got 1 wrong label possibly

Q7: respirometer what is the equation for aerobic respiration

don’t think I got anything wrong

Q8: greenhouse gases, greenhouse gas effect, calculating percentage of emissions by energy production, commenting on results,

forgot water vapour is green house gas (-1)

Q9: flower, sexual vs asexual reproduction 3 differences, artificial and natural in plants,

ASEXUAL no genetic variation VS sexual

ASEXUAL needs no mate VS sexual

ASEXUAL faster & no need to find mate so more daughter cells

Q10: woman with 4.3 litres of blood calculation (3 marks)

Q11: percentage difference in mass of haemoglobin calculation (WHY MASS HAEMOGGLOBYN INCREASES BUT NUMBER RED BLOOD CELLS DECREASES) (2 marks)

haemoglobin mass /\ for 2nd highest altitude but decreases 3rd highest this is because person takes heavier/deeper breaths where they get in more O2 so mass haemoglobin decreases

mass RBC decreases because less o2 to carry

Q12 comment on results (5 marks)

don’t think I got anything wrong,

Q13 three differences between WBCs and RBCs structure(3 marks)

RBC have no nucleus

RBC have a biconcave shape

RBC has haemoglobin

Q14: cystic fibrosis what happens if it blocks the pancreas and effect on build up in the cervix,

blocking the sperm so no fusion so decreased successful pregnancy

for the pancreas it blocks the [pancreas with secretes PROTEASE, LIPASE AND AMYLASE] hence some material TAKES LONGER TO DIGEST and ALSO IT MEANS LESS IS ABSORBED

Q15: different solutions of mineral ions and why might in an experiment they use full concentration and not dilute it with water

full concentrations ensures that the full effects are visible

q16: designing experiment for the co2 concentration for maximum crop yield

Use differing amounts of soda lime to very CO2 exposure AND maintain different 5 different plants same weight, species, high, age and put them in dark room for 48 hours to reduce photosynthesis rate to 0 and one of them has no soda lime and different amounts of differing concentrations and ensure same exposure to sun light and water and mineral ions in the soil and the same amount of sunlight access and then you measure the thing and you measure change in height or number of leaves or weight and you repeat multiple time, take average, discount anomalous results

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