CAT 2018 Slot 1 — VARC Question 25
The passage given below is followed by four summaries. Choose the option that best captures the author’s position.
Artificial embryo twinning is a relatively low-tech way to make clones. As the name suggests, this technique mimics the natural process that creates identical twins. In nature, twins form very early in development when the embryo splits in two. Twinning happens in the first days after egg and sperm join, while the embryo is made of just a small number of unspecialized cells. Each half of the embryo continues dividing on its own, ultimately developing into separate, complete individuals. Since they developed from the same fertilized egg, the resulting individuals are genetically identical.
Answer & solution
- A
Artificial embryo twinning is just like the natural development of twins, where during fertilization twins are formed.
- B
Artificial embryo twinning is low-tech and is close to the natural development of twins where the embryo splits into two identical twins.
- C
Artificial embryo twinning is low-tech unlike the natural development of identical twins from the embryo after fertilization.
Artificial embryo twinning is low-tech and mimetic of the natural development of genetically identical twins from the embryo after fertilization.
Easy
This is a para-summary question. Nail the central idea of the paragraph, then eliminate options that distort facts, add information not stated, or omit something essential. The passage makes two key claims: artificial embryo twinning is a low-tech way to make clones, and it mimics the natural process in which a single fertilised embryo splits to produce genetically identical individuals.
Fix the central idea. Two non-negotiable points must survive in the summary: (a) the technique is low-tech and mimics nature, and (b) in nature, twins arise when a single fertilised embryo splits, yielding genetically identical individuals. Note the timing: twinning happens in the first days after egg and sperm join — i.e. after fertilisation, not during it.
Option 1 — distorts timing, drops "low-tech". It says twins form "during fertilization." The passage clearly states twinning happens in the first days after egg and sperm join. It also omits the "low-tech" point. Eliminate.
Option 2 — close, but incomplete. It keeps "low-tech" and the splitting embryo, but it skips that the resulting individuals are genetically identical and that the splitting follows fertilisation. It captures the mechanism loosely while leaving out the defining outcome. A weaker fit than option 4.
Option 3 — sets up a false contrast. The word "unlike" implies twinning differs from natural twin development, whereas the passage says it mimics nature. This reverses the author's point. Eliminate.
Option 4 — complete and faithful. "Low-tech" + "mimetic of the natural development" + "genetically identical twins from the embryo after fertilization" packs in every essential point with correct timing and no distortion. This is the best summary.
The correct answer is Option 4: Artificial embryo twinning is low-tech and mimetic of the natural development of genetically identical twins from the embryo after fertilization.