LC Biology case studies
LC Biology · Put your knowledge to work in context.
Leaving Certificate Biology is the Irish senior-cycle biology subject, examined by the State Examinations Commission (SEC) and offered at Higher and Ordinary Level. It suits students who want a laboratory-based science subject for third-level entry in medicine, nursing, veterinary, agriculture, food science, pharmacy or environmental fields, and it also counts as a science subject for many general degree programmes. The LC Biology case studies are 5 cases and about 2,702 words.
1Catalase and the pH conclusion that outran the data
A student investigates the effect of pH on catalase activity in potato tissue. She cuts 1 g of potato into discs, adds them to 5 cm³ of 3% hydrogen peroxide adjusted to pH 4, 6, 7, 8 or 10 with buffer solution, and records the volume of oxygen collected in a gas syringe after 60 seconds.
589 words, about 3 min2Cystic fibrosis: a negative carrier test in a family with an affected child
A couple, both aged 32, have a 4-year-old daughter with cystic fibrosis. Neither parent has symptoms.
483 words, about 2 min3Pondweed bubbles: light intensity or rising temperature?
A student investigates the effect of light intensity on the rate of photosynthesis in Elodea. She places a lamp at 10, 20, 30, 40 and 50 cm from a test tube containing pondweed in 1% sodium hydrogen carbonate solution and counts the oxygen bubbles released in 2 minutes.
550 words, about 3 min4A lake below a sewage outfall: nutrients, algae and oxygen
A river enters a lake and flows out at the far end. Four stations are sampled at 2 pm on a sunny July day: A upstream of the lake, B 50 m below a sewage treatment outfall, C 500 m downstream of B, and D 2 km further downstream.
551 words, about 3 min5At 3,500 m: acclimatisation or emergency?
A 24-year-old sea-level athlete travels to 3,500 m. At rest on day 1: breathing rate 20 min⁻¹ (sea level 12), tidal volume 0.6 L (0.5 L), heart rate 95 (58), arterial oxygen saturation 88% (98%), arterial pH 7.47 (7.40), haematocrit 45% (42%).
529 words, about 3 min