CAT 2024 Slot 3 — VARC Question 2
Five jumbled up sentences (labelled 1, 2, 3, 4 and 5), related to a topic, are given below. Four of them can be put together to form a coherent paragraph. Identify the odd sentence and key in the number of that sentence as your answer.
1. To create a synapse, the neuron has specialized structures, often seen as tiny swellings, at its terminal end of the axon where it stores the chemicals that are emitted to transmit a signal to the next neuron.
2. This fetal warm-up act—the soldering of neural connections before the eyes actually function—is crucial to the performance of the visual system.
3. The reasons for this paring back of synapses is a mystery, but synaptic pruning is thought to sharpen and reinforce the “correct” synapses, while removing the weak and unnecessary ones.
4. Neural connections between the eyes and the brain are formed long before birth, establishing the wiring and the circuitry that allow a child to begin visualizing the world the minute she emerges from the womb.
5. During this rehearsal period, synapses—points of chemical connection—between nerve cells are generated in great excess, only to be pruned back during later development.
Answer & solution
Answer: 1
Easy
Four sentences should form a coherent paragraph; one is off-topic. Find the core theme, build the chain, and the leftover sentence is the answer.
Spot the theme. Sentence 4 opens the topic: neural connections between eyes and brain form before birth (the "wiring"). Sentence 2 calls this prenatal activity a "fetal warm-up act" crucial to the visual system — it directly elaborates 4. Sentence 5 describes "this rehearsal period" in which synapses are over-generated then pruned. Sentence 3 explains the mystery and purpose of that "paring back of synapses". So 4–2–5–3 is a tight chain on prenatal vision and synaptic pruning.
Test the candidate. Sentence 1 defines, in general anatomical terms, how a neuron builds a synapse (swellings at the axon terminal storing chemicals). It is a generic mechanism statement, not tied to the eye–brain prenatal-development narrative or to pruning. It breaks the dedicated flow of 4–2–5–3.
Conclude. The four sentences 2, 3, 4, 5 cohere; sentence 1 is the intruder.
The odd sentence is 1.