1. Overpowering prey is a challenge for limbless creatures. Some species inject venom like Russell’s viper. Some others opt for an alternative non–chemical method – rat snakes, for instance, grab and push their prey against the ground, while pythons use their brawn to squeeze their quarry to death. But snakes can’t be neatly divided into venomous and non–venomo.
2. Even species listed as non–venomous aren’t completely devoid of venom. The common sand boa, for instance, produces secretions particularly toxic to birds. So the species doesn’t hedge its bets – it constricts its prey and injects venom for good measure.
3. Do vipers need venom potent enough to kill hundreds of rats with just one drop? After all, they eat only one or two at a time.
4. While predators try their darndest to kill most efficiently, their prey use any trick to avoid becoming a meal, such as developing immunity to venom. For instance, Californian ground squirrels are resistant to Northern Pacific rattlesnake venom.
5. Competition with prey is not the only thing driving snakes to evolve more and more toxic venom. Snakes also struggle to avoid becoming prey themselves.
6. Some snake predators have partial immunity to venom. Famously, mongooses are highly resistant to cobra venom, and with their speed and agility, kill snakes with impunity. It would be the death of cobras as a species if they didn’t evolve more toxic venom to immobilise mongooses.
7. Venom has another important role. It’s an extreme meat tenderiser; specific enzymes disintegrate the innards of prey. Normally, a reptile depends on the sun’s warm rays to aid digestion. Venomous snakes have an advantage: enzymes in venom digest the meal from the inside before it rots in their guts.
8. But I wonder if we, cannot use venom in our favour. In remote parts of India, local hospitality often involves leather–tough meat. I chew and chew until my jaws ache. If I spit it out or refuse, our hosts would be offended. Eventually, I swallow like a python stuffing a deer down its throat and hope I don’t choke. If only I had venom.
6.1. On the basis of your reading of the passage, answer the following questions in 30–40 words each:
(a) Russel viper and Rat snake have different methods to attack its prey. Explain.
Russels viper is a venomous snake. It injects venom into its prey, whereas rat snakes use an alternative non–chemical method–push and grab their prey against the ground immobilising it.
(b) How does sand boa kill its prey?
The sand boa first captures its prey and then injects venom. Though it belongs to the non venomous category but it does secrete some venom which is enough to kill the prey.
(c) There is a constant tussel between the predators of the prey. Why?
This is but natural because the predator has to kill and the prey has to protect itself. The ground squirrels in California are resistant to the venom of rattle snake. They develop immunity from the venom. The predator has to then think of other ways.
(d) Snakes have to guard themselves against their predators as well. How do they do this?
Snakes use their venom not only to kill their prey but also to prevent their predators from reaching them. Some of their predators, for example, mongooses are resistant to the venom. Therefore the snakes have to constantly evolve more toxic venom.
6.2. On the basis of your reading of the passage, answer of the following:
(a) The synonym of another’, in para 1 is __________.
(i) squeeze
(ii) alternative
(iii) similar
(iv) quarry
Correct option is (ii) alternative
(b) The opposite word of ‘full in para 2 is ____________.
(i) complete
(ii) measure
(iii) completely
(iv) devoid
Correct option is (iv) devoid
(c) Snakes use their venom not only to kill their prey but also to prevent their predators from reaching them. (True/False)
True
(d) Mongooses, who are highly resistant to cobra venom, kill snakes __________.
with their speed, agility and impunity
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