This year’s DSE Biology Paper 1 (core) was easier than last year’s, but Paper 2 (electives) was harder, teachers said.
Section 1A, which consisted of 36 multiple choice questions, was one of the easiest in the five years since the Biology DSE exam was established, said Hugo Kam, a tutor at Modern Education.
“Most of the topics and question types have appeared in past papers before,” he said.
But Scarlett Chu, a tutor at Beacon College, pointed out that some of the questions, such as Q4 on the make up of a polynucleotide and Q12 on microscopes, tested some very basic knowledge that students might have overlooked.
“Reasons for using high or low magnification in a microscope are topics students learn in Form Three, so they may not have revised that, thinking it isn’t important,” she said.
One unfamiliar multiple choice question was Q14, where students were asked for the first time in the DSE to pick the correct evolutionary tree from the data provided.
Section 1B, which consisted of 10 structural questions and an essay question, was also pretty straightforward.
“Q3 tested photosynthesis, which hadn’t appeared before, so it was expected to come up,” said Yau Chak-man, a teacher at Christian Alliance SC Chan Memorial College.
However, Kam noted that this question could have been tricky because it required students to identify parts observed in a micrograph. Students who cannot would likely lose all six marks in this question. “There is a trend of including more micrographs and images in the exam, so students can’t just memorise biological processes from textbooks,” he said.
Kam added that while there are usually three experiment-based questions in Section 1B, this year there was just one. Q8, one of the toughest questions of the section, tested students on the regeneration of algae. Chu said most students are accustomed to thinking that algae regenerate with the cap, but in this case it regenerated from the root. “Students need a bit of imagination and need to have the flexibility to unlearn some of their preconceptions,” she said. This question also asked about the “nature of science” demonstrated in the experiment. Yau said it is relatively difficult for students to score marks here, because they must answer using the correct keywords mentioned in the narrow marking scheme. “This was also tested last year and even students who got Level 5** last year couldn’t get marks,” he said.
Q5 was another tough questions, said Chu, because students would not have previously studied the lethal temperature introduced in the question. Establishing two habitats, middle shore and lower shore, further distracted students.
“When doing questions that you are unfamiliar with, remember that the Examination Authority will only test things you have already learned,” she said. “Think about which topic they are assessing you on. Usually when you see past this, the question is quite simple.”
Yau added that students with field trip experience would be better equipped to handle this question, but he said it was more difficult to arrange field trips for DSE biology students compared with the previous A-Level students, because of the greater number of students that take the subject.
Yau said what surprised him most was Q10, a 13-mark question on genetics. “That’s a lot of marks, so students strong in this area could easily get a level up,” he said.
The essay question, which asked students to compare the gas exchange mechanisms in plants and humans, was quite easy, said Kam. The key was to compare the common factors, instead of just stating separately how plants and humans exchanged gas. “So it’s crucial to find the keyword in the question to identify what it’s testing you on,” he said. Chu recommended studying marking schemes and pinpointing how it relates to the question asked.
The teachers agreed that Paper Two was challenging. Section A (Human Physiology: Regulation and Control) and Section C (Microoganisms and Humans) involved applications that may be familiar in daily life (athletes in Q1; sushi in Q3), but Section B (Applied Ecology) and Section D (Biotechnology) involved unfamiliar issues that seldom appear in textbooks. Q2 tested about antibiotics in water, and Q4 on Parkinson’s disease.
A student surnamed Wong who sat the exam today said she also noted more data interpretation in this years’ questions. “2b (Applied Ecology) is a super clumsy question about data interpretation. It didn’t need much knowledge about biological principles, but that’s the problem because the answers cannot be recited. You need to make sense of the given data,” she said.
“It’s very clear that core concepts that are mostly tested in Paper One have a bigger presence in Paper Two. This year it covered about 50 per cent of the marks, whereas it would have been 30 to 40 per cent in previous years,” said Kam. “Many textbooks separate core and elective content, and it’s especially hard for students to make the connection.” For example, Q4 began by asking students about the central nervous system, before going on to ask about the biotechnology involved in curing Parkinson’s disease.
For students preparing for the DSE biology exam in the coming years, Chu said the ecosystem would continue to be a topic of focus. She said it was also important to study topics with experiments involved thoroughly, such as plant-based topics, because that’s usually how new questions are conceived. Kam also suggested focusing less on memorisation, but understanding concepts through graphs and images. He said it is also key to pay attention during lab sessions to learn about the logic and purpose of various experimental set ups, as he believes this will continue to be a focus of exam questions. “Some schools only arrange for their students to do experiments once a year, which is the basic requirement by the examination authority,” he said. “Because the more experiments the teachers arrange, the more work it is for them.”
He also recommends students read science articles to help with applications questions.
To get a pass, or Level 2, Kam said students would need around 35 per cent. To get a Level 4, students would need around 55 per cent. Since the paper this year was relatively easy, he said about 80 per cent would be needed to get a Level 5**.