Question

4. How will you test a leaf for the presence of starch?​

Answer 1

Answer:

sᴛᴀʀᴄʜ ᴛᴇsᴛɪɴɢ

ɪᴏᴅɪɴᴇ sᴏʟᴜᴛɪᴏɴ ɪs ᴜsᴇᴅ ᴛᴏ ᴛᴇsᴛ ʟᴇᴀᴠᴇs ғᴏʀ ᴛʜᴇ ᴘʀᴇsᴇɴᴄᴇ ᴏғ sᴛᴀʀᴄʜ. ... ʜᴇᴀᴛ ᴀ ᴘʟᴀɴᴛ ʟᴇᴀғ ɪɴ ʙᴏɪʟɪɴɢ ᴡᴀᴛᴇʀ ғᴏʀ 30 sᴇᴄᴏɴᴅs (ᴛʜɪs sᴛᴏᴘs ɪᴛs ᴄʜᴇᴍɪᴄᴀʟ ʀᴇᴀᴄᴛɪᴏɴs) ʜᴇᴀᴛ ɪᴛ ɪɴ ʙᴏɪʟɪɴɢ ᴇᴛʜᴀɴᴏʟ ғᴏʀ ᴀ ғᴇᴡ ᴍɪɴᴜᴛᴇs (ᴛʜɪs ʀᴇᴍᴏᴠᴇs ᴍᴏsᴛ ᴏғ ɪᴛs ᴄᴏʟᴏᴜʀ) ᴡᴀsʜ ᴡɪᴛʜ ᴡᴀᴛᴇʀ ᴀɴᴅ sᴘʀᴇᴀᴅ ᴏɴᴛᴏ ᴀ ᴡʜɪᴛᴇ ᴛɪʟᴇ.

Answer 2

Answer:

Starch testing

Iodine solution is used to test leaves for the presence of starch. ... heat a plant leaf in boiling water for 30 seconds (this stops its chemical reactions) heat it in boiling ethanol for a few minutes (this removes most of its colour) wash with water and spread onto a white tile.