Read the passage given below and answer the questions that follow :
The most characteristic feature of spiders is their ability to produce silken threads. Spiders
normally have six fingerfike 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 to 140 percent of its original length. The diameter of these silken threads is
about ten-thousand of an inch. This silk is used 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 them 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 intrinsic existence value. They are
efficient predators that play an important role in controlling 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.
Based on the passage answer the following questions :
(a) What is so special about spiders
(b) How does a spider spin a web
(c) Write one feature of spider silk.
(d) Why are egg sacs made of silk 1’
(e) Do spiders learn to make web
(f) What important role do spiders play as a predator
(g) Why are spiders important forbirds and wasps
(h) Choose words from paragraph which means, ’Essential'.
Answers
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(a) The ability to produce silken threads makes the spider so special.
(b) The spider squeezes the silk out of its body. Since it is thicker, it dries into fine thread when it comes in contact with the air.
(c) Spider silk is stronger than steel.
(d) The egg sacs are made of silk so as to pretreat the unborn progeny.
(e) The spinning of webs is a remarkable example of its instinctive behaviour. Hence, a spider does not have to learn to make a web.
(f) As a predator, spiders play an important role in controlling the pests of cotton.
(g) Spiders are important for birds and wasps as they are the source of food for them.
(h) ’Integral'
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