1. Give reasons:
(a) Meristematic cells have a prominent nucleus and dense cytoplasm but they lack vacuole.
(b) Intercellular spaces are absent in sclerenchymatous tissues.
(c) We get a crunchy and granular feeling when we chew pear fruit.
(d) Branches of a tree move and bend freely in high wind velocity.
(e) It is difficult to pull out the husk of a coconut tree.
Answers
(a) Meristematic cells have a prominent nucleus and dense cytoplasm but they lack vacuole.
●- ᴍᴇʀɪsᴛᴇᴍᴀᴛɪᴄ ᴄᴇʟʟs ᴀʀᴇ ᴄᴏɴᴛɪɴᴜᴏᴜsʟʏ ᴅɪᴠɪᴅɪɴɢ ᴄᴇʟʟs sᴏ ᴛʜᴇʏ ʜᴀᴠᴇ ᴀ ᴘʀᴏᴍɪɴᴇɴᴛ ɴᴜᴄʟᴇᴜs ᴀɴᴅ ᴅᴇɴsᴇ ᴄʏᴛᴏᴘʟᴀsᴍ. ʙᴜᴛ sɪɴᴄᴇ ᴛʜᴇsᴇ ᴄᴇʟʟs ᴅᴏ ɴᴏᴛ sᴛᴏʀᴇ ғᴏᴏᴅ ᴍᴀᴛᴇʀɪᴀʟ ᴏʀ ᴡᴀsᴛᴇ ᴍᴀᴛᴇʀɪᴀʟs, ᴛʜᴇʏ ʟᴀᴄᴋ ᴠᴀᴄᴜᴏʟᴇ. sᴄʟᴇʀᴇɴᴄʜʏᴍᴀ ᴄᴇʟʟs ʜᴀᴠᴇ ʟɪɢɴɪғɪᴇᴅ ᴄᴇʟʟ ᴡᴀʟʟs ᴡʜɪᴄʜ ᴍᴀᴋᴇs ᴛʜᴇᴍ ᴄᴏᴍᴘᴀᴄᴛ ᴀɴᴅ ʟᴇᴀᴠᴇs ɴᴏ ɪɴᴛᴇʀᴄᴇʟʟᴜʟᴀʀ sᴘᴀᴄᴇs...
(b) Intercellular spaces are absent in sclerenchymatous tissues.
●- ɪɴᴛᴇʀᴄᴇʟʟᴜʟᴀʀ sᴘᴀᴄᴇs ᴀʀᴇ ᴀʙsᴇɴᴛ ɪɴ sᴄʟᴇʀᴇɴᴄʜʏᴍᴀᴛᴏᴜs ᴛɪssᴜᴇs ʙᴇᴄᴀᴜsᴇ ᴛʜᴇʏ ʜᴀᴠᴇ ᴀ ᴄᴇᴍᴇɴᴛɪɴɢ sᴜʙsᴛᴀɴᴄᴇ (ᴋɴᴏᴡɴ ᴀs ʟɪɢɴɪɴ) ᴀʀᴏᴜɴᴅ ᴛʜᴇɪʀ ᴄᴇʟʟ ᴍᴇᴍʙʀᴀɴᴇ ᴡʜɪᴄʜ ᴍᴀᴋᴇs ᴛʜᴇᴍ sᴛɪғғ ᴀɴᴅ ʜᴀʀᴅ...
(c) We get a crunchy and granular feeling when we chew pear fruit.
●- ɪɴ ᴀ ᴘᴇᴀʀ ғʀᴜɪᴛ, ᴄᴇʟʟs ᴏғ sᴄʟᴇʀᴇɴʜʏᴍᴀ ᴀʀᴇ sᴍᴀʟʟ, ʀᴏᴜɴᴅᴇᴅ ᴀɴᴅ ᴄᴀʟʟᴇᴅ sᴛᴏɴᴇ ᴄᴇʟʟs. ᴛʜᴇʏ ᴀʀᴇ ʜᴀʀᴅ ᴡɪᴛʜ ʜɪɢʜʟʏ ᴛʜɪᴄᴋᴇɴᴇᴅ ᴄᴇʟʟ ᴡᴀʟʟ. ᴛʜᴇsᴇ ᴄᴇʟʟs ɢɪᴠᴇ ᴛʜᴇ ᴄʀᴜɴᴄʜʏ ᴀɴᴅ ɢʀᴀɴᴜʟᴀʀ ғᴇᴇʟɪɴɢ ᴡʜᴇɴ ᴡᴇ ᴄʜᴇᴡ ᴘᴇᴀʀ ғʀᴜɪᴛ...
(d) Branches of a tree move and bend freely in high wind velocity.
●- ʙʀᴀɴᴄʜᴇs ᴏғ ᴀ ᴛʀᴇᴇ ᴍᴏᴠᴇ ᴀɴᴅ ʙᴇɴᴅ ғʀᴇᴇʟʏ ɪɴ ʜɪɢʜ ᴡɪɴᴅ ᴠᴇʟᴏᴄɪᴛʏ ʙᴇᴄᴀᴜsᴇ ᴏғ ᴛʜᴇ ᴘʀᴇsᴇɴᴄᴇ ᴏғ ᴄᴏʟʟᴇɴᴄʜʏᴍᴀ ᴛʜᴀᴛ ᴀᴅᴅs ᴛʜᴇ ᴘʀᴏᴘᴇʀᴛʏ ᴏғ ғʟᴇxɪʙɪʟɪᴛʏ...
(e) It is difficult to pull out the husk of a coconut tree.
●- ɪᴛ ɪs ᴅɪғғɪᴄᴜʟᴛ ᴛᴏ ᴘᴜʟʟ ᴏᴜᴛ ᴛʜᴇ ʜᴜsᴋ ᴏғ ᴀ ᴄᴏᴄᴏɴᴜᴛ ᴛʀᴇᴇ ʙᴇᴄᴀᴜsᴇ ɪᴛ ɪs ᴍᴀᴅᴇ ᴜᴘ ᴏғ sᴄʟᴇʀᴇɴᴄʜʏᴍᴀ ᴛɪssᴜᴇs ᴡʜɪᴄʜ ᴀʀᴇ ᴅᴇᴀᴅ ᴄᴇʟʟs. ᴛʜɪs ɢɪᴠᴇs ʀɪɢɪᴅɪᴛʏ ᴀɴᴅ sᴛɪғғɴᴇss...
ʜᵒᵖᵉ ⁱᵗ'ˢ ʰᵉˡᵖ ʸᵒᵘ.....
ʜᵒᵖᵉ ⁱᵗ'ˢ ʰᵉˡᵖ ʸᵒᵘ.....ғᵒˡˡᵒʷ ᴍᵉ ᴘˡᵉᵃˢᵉ.....
Explanation:
a) Meristamatic tissue cells are continuously dividing and they have prominent nucleus and a dese cytoplasm. Since they are diving rigorously they need not store food or waste products hence they lack vacuoles.
b) Cellwall of sclerenchyma are lignified and are packed densely to protect the plant and to give mechanical strength hence intercellular spaces are absent in sclerenchymatous tissues.
c) In pear fruit sclerenchyma cells are called stone cells. They are small, thick and hard. Because of this We get a crunchy and granular feeling, when we chew pear fruit.
d) Junction of the tree branch composed of collenchyma cells which provide rigidity and flexibility to the branches. Hence Branches of a tree move and bend freely in high wind velocity
e) Husk of coconut tree is sclerenchyma which is hard. Hence it is difficult to pull out the husk of a coconut tree
hopefully it will work ☺️☺️