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Fill in the blanks: In older trees , t...

Fill in the blanks:
In older trees , the greater part of …a…. Is dark brown due to deposition of tannins, resins, oil, guns, aromatic substances and essential oil in the central layers of the stem. These substances make it hard durable and resistant to the attacks of microorganisms and insects .This region is called .. b ...

A

a- secondary xylem, b- sapwood

B

a- secondary xylem, b- heartwood

C

a- secondary phloem,, b- softwood

D

a- secondary xylem, b- hardwood

Text Solution

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In older trees the greater part of secondary xylem is dark brown due to deposition of tannins resins oil gund aromatic substances and essential oil in the central layers of the stem. These substances make it hard durable and rsistant to the attacks opf microoorganisms and insects. This region is called heartwood.
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Statement-1 : The heart wood is more durable and resistant to the attack of the micro orgganims and insects as compared ot the sap wood. Statement-2: The heart wood contain organic compounds like oils , aromatic substance , gums, resin, tannins and phenol etc.

A2Z-ANATOMY OF FLOWERING PLANTS-Section A : Topicwise Questions Topic 6 : Secondary Growth (vascular Cambium , Cork Cambium And Seco
  1. Match the columns I II and III and choose the correct combination from...

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  2. The climatic conditons are not uniform through the year in

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  3. Recognise the figure and find out the correct matiching

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  4. Cambium is a lateral meristem that takes part in

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  5. Fill in the blanks: In older trees , the greater part of …a…. Is dar...

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  6. cellular layers form outside to inside in old dicot stem are

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  7. The peripheral region of the secondary xylem is lighter in colour and ...

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  8. older resin-clogged central seconedary xylem and younger outer seconda...

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  9. Recognise the figure and find out the correct matiching

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  10. Read the following statements and find out the incorrect statement

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  11. vascular cambium of stem is

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  12. Which of the following statement is / are not true A. Cork cambium i...

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  13. Recognise the figure and find oput the correct matching

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  14. Cambium ring in dicot stem consist of

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  15. meristem present in a vascular bundle is

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  16. Which meristem helps in increasing girth?

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  17. Among the following , secondary growth is seen in a-dicot root, b-dico...

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  18. Cork/bottle cork is formed from

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  19. Recognise the figure and find out the correct matching

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  20. In dicot root showing secondary growth, cork is found

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