AQA GCSE Biology Biology Paper 2 (Foundation), June 2022: Question 7

✅ Correct Answers

• Top missing row: Kingdom
• Lower missing row: Genus

Must be in this exact order to match the hierarchy.

💡 Key Knowledge

Remember the order from highest to lowest rank using a mnemonic:

King Philip Came Over For Good Soup

Kingdom → Phylum → Class → Order → Family → Genus → Species

❌ Common Errors

• Confusing Genus with Species or choosing irrelevant ecological terms like Community or Population.
• Writing "Mammal" (which is a Class, not a classification rank).

✅ Correct Answer

Tick: Linnaeus (Carl Linnaeus)

💡 Key Knowledge: Scientist Roles

• Linnaeus: Classification system and binomial naming.
• Darwin: Theory of evolution by natural selection.
• Lamarck: Theory of acquired characteristics (use and disuse).
• Mendel: Father of modern genetics (inheritance in pea plants).

🧠 Exam Technique

Don't confuse evolutionary scientists with taxonomists! Linnaeus pioneered grouping organisms by shared visible characteristics long before Darwin proposed natural selection.

✅ Correct Answer

Tick: Elrathia kingii

💡 Key Knowledge

The binomial system gives every species a two-word Latin name:

• First word: Genus (capitalised) → Elrathia
• Second word: Species (lowercase) → kingii

❌ Common Errors

• Selecting Arthropoda kingii (pairing Phylum with Species).
• Selecting Trilobita kingii (pairing Class with Species).

✅ Correct Answers (Tick two boxes)

• ☑ Trilobite A was found in older rocks than trilobite B.
• ☑ Trilobite B is more complex than trilobite A.

💡 Key Knowledge: Reading the Diagrams

• Figure 11 (Rock Strata): Sedimentary rock layers form chronologically. Deeper layers are older. Trilobite A is in a deeper, lower layer than B, proving A existed earlier in time.
• Figure 10 (Fossil Anatomy): Trilobite B has more ribs, distinct segments, and extended spine-like features compared to the smoother, simpler body shape of A. Evolution generally progresses towards greater structural complexity.

❌ Common Errors

• Ticking "were in the same type of rock" — doesn't support an ancestor-descendant timeline.
• Ticking "smaller mass" or "different colour" — rock colours in diagrams or specimen mass do not provide scientific evidence for evolutionary divergence.

✅ Correct Answers

The animal dies and falls to the sea bed.

• The animal is buried in sediments. [1]
• The soft parts of the animal decay. [1]
• The remains which do not decay are replaced by minerals. [1]

Must be in this exact order.

💡 Key Knowledge: How Fossils Form

1. Organism dies and quickly sinks, getting covered by sediment (sand, silt, mud), preventing scavengers from destroying it.
2. Microbes break down only the soft tissues (soft parts decay).
3. Hard parts (shells/exoskeletons) undergo mineralisation: dissolved minerals seep in through groundwater and turn the remains to stone over millions of years.

❌ Common Errors

• Writing "bones" decay — trilobites are arthropods with exoskeletons, not vertebrates with bones!
• Swapping sediments and minerals.

✅ Correct Answers (Choose any three)

• Climate change (e.g. drought, ice age, global warming)
• Catastrophic events (e.g. volcanic activity, asteroid collision)
• New predators (or hunting)
• New disease / new pathogen
• Competition for food
• Competition for mates
• Loss of habitat / habitat change

🧠 Exam Technique: Be Specific!

Examiners frequently penalise vague answers here:

• Do not just say "competition" — you must specify what they compete for: competition for food or competition for mates.
• Do not write "weather" — weather is day-to-day. You must state climate change, drought, or ice age.
• Do not write just "pollution" (unqualified).

❌ Common Errors

• Writing overlapping points, e.g., "ice age" and "climate change" (these only award 1 mark together).
• Saying "they died out" — this is the definition of extinction, not a cause!

✅ Correct Answers (Any one of the following)

• There is no / insufficient / lack of evidence.
• Cannot perform an experiment to find out.
• No-one was there to observe what happened.

💡 Key Knowledge: Incomplete Fossil Records

Trilobites lived 400 to 500 million years ago. Most dead organisms do not fossilise because they decay completely or are destroyed by geological processes (earthquakes, erosion, melting into magma).

Therefore, the fossil record contains large gaps, meaning definitive proof of the exact triggering event is impossible to observe directly.

🧠 Exam Technique

A simple, clear sentence like "There is insufficient fossil evidence" or "No humans were alive to observe it" is all that is required for this 1-mark 'suggest' question.