6 exam-style questions with full mark schemes and model answers. Write your own answer and the AI examiner marks it against the mark scheme.
Learn this properly: Cell Division and GrowthA person accidentally touches a very hot oven tray and pulls their hand away almost instantly, before they feel any pain. This is a reflex action.
Describe and explain how the reflex arc produces this rapid response. In your answer you should refer to the named parts of the pathway, the role of synapses, and why a reflex response is faster than a normal voluntary response. (6 marks)
In pea plants, the allele for tall stems (T) is dominant to the allele for short stems (t). A gardener crosses two pea plants that are both heterozygous (Tt).
(a) Complete a genetic diagram (Punnett square) for this cross to show the genotypes of the offspring. (2 marks)
(b) State the ratio of tall to short offspring expected, and give the probability (as a percentage) that any one offspring will be short. (2 marks)
A person looks up from reading a book to focus on a tree far away in the distance.
Describe and explain how the ciliary muscles, suspensory ligaments and lens change to allow the eye to focus on the distant tree. (3 marks)
The brain is the main coordinating centre of the central nervous system. The table lists three regions of the brain.
| Region | Function |
|---|---|
| Cerebral cortex | (i) |
| Cerebellum | (ii) |
| Medulla oblongata | (iii) |
(a) Complete the table by stating one function of each region: (i) cerebral cortex, (ii) cerebellum, (iii) medulla oblongata. (2 marks)
(b) Suggest one reason why it is difficult to treat damage or disease in the brain. (1 mark)
Neurones do not touch one another. Where two neurones meet there is a tiny gap called a synapse.
Explain how a nerve impulse is transmitted across a synapse from one neurone to the next. (2 marks)
A pea plant with the genotype Tt is described as heterozygous for stem height.
State what is meant by the term heterozygous. (1 mark)