CAT 2022 Reading Comprehension Solution 06

[PASSAGE]

The passage below is accompanied by a set of questions. Choose the best answer to each question.

[Octopuses are] misfits in their own extended families . . . They belong to the Mollusca class Cephalopoda. But they don’t look like their cousins at all. Other molluscs include sea snails, sea slugs, bivalves – most are shelled invertebrates with a dorsal foot. Cephalopods are all arms, and can be as tiny as 1 centimetre and as large at 30 feet. Some of them have brains the size of a walnut, which is large for an invertebrate. . . .

It makes sense for these molluscs to have added protection in the form of a higher cognition; they don’t have a shell covering them, and pretty much everything feeds on cephalopods, including humans. But how did cephalopods manage to secure their own invisibility cloak? Cephalopods fire from multiple cylinders to achieve this in varying degrees from species to species. There are four main catalysts – chromatophores, iridophores, papillae and leucophores. . . .

[Chromatophores] are organs on their bodies that contain pigment sacs, which have red, yellow and brown pigment granules. These sacs have a network of radial muscles, meaning muscles arranged in a circle radiating outwards. These are connected to the brain by a nerve. When the cephalopod wants to change colour, the brain carries an electrical impulse through the nerve to the muscles that expand outwards, pulling open the sacs to display the colours on the skin. Why these three colours? Because these are the colours the light reflects at the depths they live in (the rest is absorbed before it reaches those depths). . . .

Well, what about other colours? Cue the iridophores. Think of a second level of skin that has thin stacks of cells. These can reflect light back at different wavelengths. . . . It’s using the same properties that we’ve seen in hologram stickers, or rainbows on puddles of oil. You move your head and you see a different colour. The sticker isn’t doing anything but reflecting light – it’s your movement that’s changing the appearance of the colour. This property of holograms, oil and other such surfaces is called “iridescence”. . . .

Papillae are sections of the skin that can be deformed to make a texture bumpy. Even humans possess them (goosebumps) but cannot use them in the manner that cephalopods can. For instance, the use of these cells is how an octopus can wrap itself over a rock and appear jagged or how a squid or cuttlefish can imitate the look of a coral reef by growing miniature towers on its skin. It actually matches the texture of the substrate it chooses.

Finally, the leucophores: According to a paper, published in Nature, cuttlefish and octopuses possess an additional type of reflector cell called a leucophore. They are cells that scatter full spectrum light so that they appear white in a similar way that a polar bear’s fur appears white. Leucophores will also reflect any filtered light shown on them . . . If the water appears blue at a certain depth, the octopuses and cuttlefish can appear blue; if the water appears green, they appear green, and so on and so forth.

Question: 1

All of the following are reasons for octopuses being " misfits" EXCEPT that they:

exhibit higher intelligence than other molluscs.
do not possess an outer protective shell.
are consumed by humans and other animals.
have several arms.

Option: 3
Solution:
The answer to this question can be found only in the first paragraph or the second paragraph. We must look for the word ‘misfit’ and find the reasons behind those misfits. The one that is not the reason is the right answer. It is clearly given in the passage that most are shelled but octopuses are not. 2 goes out. They have higher cognition (higher implies that this too is an exception). 1 goes out because of this. The first paragraph also says that they are all arms, whereas others are shelled with a dorsal foot. Thus 4 also goes out. 3 is not an exception because there is no clarity whether this is a point of difference or similarity. The other three options are quite clear because they stand out as reasons behind octopuses being misfits.

Question: 2

Based on the passage, it can be inferred that camouflaging techniques in an octopus are most dissimilar to those in:

polar bears
cuttlefish
squids
sea snails

Option: 4
Solution:
For this too we must go the part of the passage where ‘camouflaging’ has been discussed. The second last paragraph compares octopuses with squids and cuttlefish. So, both 2 and 3 go out. The last paragraph discusses polar bears with octopuses. With respect of camouflaging, there is no any comparison between sea snails and octopuses. 4 is the right answer.

Question: 3

Based on the passage, we can infer that all of the following statements, if true, would weaken the camouflaging adeptness of Cephalopods EXCEPT:

the hydrostatic pressure at the depths at which Cephalopods reside renders radial muscle movements difficult.
the number of chromatophores in Cephalopods is half the number of iridophores and leucophores.
light reflects the colours red, green, and yellow at the depths at which Cephalopods reside.
the temperature of water at the depths at which Cephalopods reside renders the transmission of neural signals difficult.

Option: 2
Solution:
This could be a time-consuming question. We should find the option that is not weakening the camouflaging adeptness of Cephalopods. Three options are weakening and one is not. For option 1 we have to read the third paragraph, if radial muscle movement is difficult then the technique won’t work, weakening the whole process of camouflaging. 1 goes out. Iridophores is the second level of skin. It means the others are at the first level. But the impact of their numbers on the camouflaging process is not very clear. Thus 2 does nothing to the argument, it neither strengthens it nor weakens it. The passage says that red, brown, and yellow are reflected, the others are absorbed. It means even green is absorbed, but the option says that green is reflected. Thus, 3 weakens. If the transmission of neural signals is difficult, then the whole camouflaging process will not work. 2 is the best choice.

Question: 4

Which one of the following statements is not true about the camouflaging ability of Cephalopods?

Cephalopods can change their colour.
Cephalopods can change their texture.
Cephalopods can blend into the colour of their surroundings.
Cephalopods can take on the colour of their predator.

Option: 4
Solution:
The answer to this question could have been marked with little effort. We just have to find the word that we did not encounter anywhere else. There is nothing in the passage that talks about Cephalopods’ predators. Thus 4 becomes the right choice. The fact that camouflaging process is in place means 1, 2 and 3 are correct. 4 is not correct.

CAT 2022 RC passage with solution

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