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Subject :NSO    Class : Class 7

Shruti planted many plants belonging to two separate species X and Y in her garden. She watered them regularly and took proper care of them. Plants of both species flowered. After sometime Shruti noticed that only plants belonging to species X yielded fruits whereas fruit setting was absent in plants of species Y. What could be the probable reason for this?

APlants of species X are wind pollinated but plants of species Y are insect pollinated.
BSpecies X is dioecious whereas species Y is monoecious.
CPlants of species Y present in Shruti’s garden are dioecious male plants.
DPlants of species X bear only unisexual female flowers whereas plants of species Y bear bisexual flowers.


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Class : Class 7
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Subject :NSO    Class : Class 7

Read the given passage having some variables and few italicised words. Different respiratory organs are present in different organisms. X is the main respiratory organ in humans. Respiratory system of cockroach consists of small openings on the sides of its body called tracheoles which are connected to the tubes called tracheae that are further branched into spiracles. Scoliodon respires through Y which is richly supplied with blood vessels. Z is the main site of gaseous exchange in plants. Each Z is guarded by two kidney shaped subsidiary cells which are further flanked by specialised epidermal cells called guard cells.
Identify X, Y and Z in the given passage and select the incorrect option regarding them.

AWhales and dolphins also have X as their respiratory organ where alveoli is the main site of gaseous exchange.
BY is the respiratory organ in tadpole larva and sea horse.
CZ is absent in all hydrophytes but is abundantly present on the upper leaf surface of all xerophytes.
DWhen pressure inside X drops, inspiration occurs and when pressure inside X starts increasing the air contained in it is pushed out causing expiration.


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