Question

Mention two methods to prevent self pollination in flowers

Answer 1

flowers contain some mechanical barriers on there stigma surface to avoid artificial pollination.
2) pollen and stigma are mature at different time to avoid self pollination

Answer 2

Answer:

ᴛʜᴇʀᴇ ᴀʀᴇ ᴛᴡᴏ ꜱᴛʀᴀᴛᴇɢɪᴇꜱ ɪɴᴠᴏʟᴠᴇᴅ ɪɴ ᴘʀᴇᴠᴇɴᴛɪɴɢ ꜱᴇʟꜰ-ᴘᴏʟʟɪɴᴀᴛɪᴏɴ ɪɴ ꜰʟᴏᴡᴇʀꜱ:

ᴅɪᴄʜᴏɢᴀᴍʏ – ɪᴛ ʀᴇꜰᴇʀꜱ ᴛᴏ ᴛʜᴇ ᴘʀᴏᴅᴜᴄᴛɪᴏɴ ᴏꜰ ᴍᴀʟᴇ ᴀɴᴅ ꜰᴇᴍᴀʟᴇ ʀᴇᴘʀᴏᴅᴜᴄᴛɪᴠᴇ ᴏʀɢᴀɴꜱ ᴀᴛ ᴅɪꜰꜰᴇʀᴇɴᴛ ᴛɪᴍᴇꜱ ɪɴ ᴏʀᴅᴇʀ ᴛᴏ ᴘʀᴇᴠᴇɴᴛ ꜱᴇʟꜰ-ꜰᴇʀᴛɪʟɪᴢᴀᴛɪᴏɴ.

ꜱᴇʟꜰ-ɪɴᴄᴏᴍᴘᴀᴛɪʙɪʟɪᴛʏ – ɪᴛ ɪꜱ ᴀ ɢᴇɴᴇᴛɪᴄᴀʟʟʏ ᴄᴏɴᴛʀᴏʟʟᴇᴅ ᴍᴇᴄʜᴀɴɪꜱᴍ ɪɴ ᴡʜɪᴄʜ ᴘᴏʟʟᴇɴ ɢʀᴀɪɴꜱ ᴏꜰ ᴀ ꜰʟᴏᴡᴇʀ ᴀʀᴇ ᴜɴᴀʙʟᴇ ᴛᴏ ᴄᴏᴍᴘʟᴇᴛᴇʟʏ ɢʀᴏᴡ ᴏɴ ᴛʜᴇ ꜱᴛɪɢᴍᴀ ᴏꜰ ᴛʜᴇ ꜱᴀᴍᴇ ꜰʟᴏᴡᴇʀ.