Unseen Passage: Spiders

Reading Comprehension

The most characteristic feature of spiders is their ability to produce silken threads. Spiders normally have six finger-like silk glands, called ‘spinnerets’ located beneath their abdomen. To spin a web, the spider squeezes the silk out of its body through two small holes. The liquid silk is thicker than water and dries into a fine thread as soon as it comes in contact with air. Spider silk is much stronger than steel and resists breakage because of its elasticity. It can stretch up to 140 per cent of its original length. The diameter of these silken threads is about 10,000 of an inch. Spiders use this silk to make webs to trap their prey. The egg sacs of some spiders are also made of silk which pretreats the unborn progeny. Sometimes the spider can also use its silk as a safety feature. A certain species of spider ‘phidippus apacheanecs’ trails a safety line of fine silk as it jumps. It uses the silk line to recover if it misses its target. The silk of ‘Naphils Spider’ is the strongest natural fibre known.

The spinning of webs is a remarkable example of instinctive behaviour. A spider does not have to learn how to make a web, although spinning itself can be adopted to unique circumstances. For example, ‘orb’ webs are circular in shape and take an hour to build. Funnel spiders spin a net-like entrance to their homes, which helps to trap food. Similarly, trap door spiders dig their homes and spin a trap door out of their silk for trapping insects. As integral components of our biosphere, spiders have an intrinsic existence value. They are efficient predators that play an important role in controlling the pests of cotton. They are also a source of food for other creatures, such as birds and wasps. Thus, the presence of spiders is an ecological indicator signalling the health of natural ecosystem.

Q. Answer the following questions:

1. What is so special about spiders?
2. How does spider silk resists breakage?
3. Write one feature of spider silk.
4. Why are egg sacs made of silk?

Answer

1. The ability to produce silken threads makes the spider so special.
2. Spider silk resists breakage because of its elasticity.
3. Spider silk is stronger than steel.
4. The egg sacs are made of silk so as to pretreat the unborn progeny.

Q. Choose the correct alternatives:

1. The silk of ___________ is the strongest natural fibre known.
   1. funnel spiders
   2. Naphils spider
   3. spider silk
   4. None of the above
2. What important role do spiders play as a predator?
   1. their silk is used to make webs to trap prey
   2. their silk pretreats the unborn progeny
   3. play an important role in controlling pests of cotton
   4. spiders spin a net-like entrance to their homes
3. Why are spiders important for birds and wasps?
   1. they are the source of food for them
   2. spiders spin a net-like entrance to their homes
   3. the spiders can use its silk as a safety feature
   4. None of the above
4. Choose words from paragraph which means, ‘essential’.
   1. unique
   2. integral
   3. progeny
   4. indicator

Answer

1. Naphils spider
2. play an important role in controlling pests of cotton
3. they are the source of food for them
4. integral