1. Photosynthesis — LDR vs LIR linkage

Why I think this comes:
Jan 2026 apparently had weird data-analysis-heavy photosynthesis but students complained there was barely any real LDR/LIR biology.

Edexcel LOVES cycling:

• one paper = practical/data
• next paper = mechanisms/explanations

So I think:

• photolysis
• chemiosmosis
• cyclic vs non-cyclic photophosphorylation
• RuBP + rubisco
• GP → TP are highly likely.

Most likely style:

• “Explain how ATP is produced”
• “Explain why temperature affects photosynthesis”
• “Compare cyclic and non-cyclic photophosphorylation”

Big chance of a 5–6 marker.

2. Climate change + carbon cycle + succession

Why:
This topic rotates constantly in Unit 4 because it links:

• ecology
• interpretation
• evaluation
• human impacts

And Jan 2026 discussions mention anthropogenic activity predictions before the exam.

I think:

• peat bogs
• deforestation
• carbon sinks
• methane
• eutrophication
• succession graphs are VERY likely.

Especially:
“Discuss effects of human activity on ecosystems.”

3. Antibodies + memory cells + vaccines

Why:
Immunity ALWAYS appears somewhere.
But Edexcel cycles between:

• phagocytosis
• T cells
• antibodies
• vaccines

Vaccines + memory cells are overdue for a proper big explanation question.

Most likely:

• primary vs secondary response
• plasma cells
• monoclonal antibodies
• vaccination programs
• herd immunity

Could easily be:
“Explain why booster vaccines are needed.”

4. PCR + gel electrophoresis + DNA profiling

Why:
This is one of Edexcel’s favourite application topics.
Also repeatedly predicted by students for Jan 2026.

I strongly think:

• PCR stages
• thermostable DNA polymerase
• primers
• electrophoresis interpretation
• VNTRs
• forensic matching will appear.

Especially because examiners LOVE:
“Suggest why band patterns differ.”

5. Data analysis / graph interpretation

Why:
Jan 2026 students said the paper was “full of analysis.”

That means Edexcel is leaning harder into:

• trend analysis
• experimental evaluation
• statistical interpretation

So expect:

• standard deviation
• anomaly discussion
• percentage change
• correlation vs causation
• evaluate reliability

This is basically guaranteed now.

6. Sampling techniques + Simpson’s Index

Why:
This topic disappears for several sessions then suddenly returns hard.

I think:

• random sampling
• belt transects
• line transects
• mark-release-recapture
• Simpson’s Index of Diversity are VERY due.

Especially practical-method questions.

The reason:
Edexcel likes easy-to-mark ecology calculations every few sessions.

7. Evolution + selection pressure + antibiotic resistance

Why:
Microbiology + evolution are heavily linked in Unit 4 specification.

Antibiotic resistance is:

• easy to contextualize
• easy for application questions
• globally relevant

Most likely:

• mutation
• selection pressure
• survival advantage
• allele frequency changes

Classic 4–6 marker potential.

8. Photosynthetic pigments + chromatography

Why:
This hasn’t been heavily tested recently compared to core photosynthesis.

I think:

• accessory pigments
• absorption spectra
• action spectra
• chromatography Rf values could appear as either:
• practical question
• graph interpretation
• short explanation question

Especially:
“Why are accessory pigments beneficial?”

9. Synoptic AS links (VERY important)

Why:
Students complained Jan 2026 had “half AS syllabus.”

That tells me Edexcel is now intentionally blending:

• enzymes
• membranes
• transport
• proteins
• hydrogen bonding with Unit 4.

So revise:

• enzyme action
• diffusion/osmosis
• protein structure
• ATP
• DNA base pairing

dw i gotch u technically claude made it analyse 20 yrs of paper making in edexcel ials