Question

Do dihybrid cross and make a punnet square when fertilization takes place between RRYY and rryy​

Answer 1

This could be calculated by using Punnet square.

Genotype: RRYY X rryy

Gametes: RY ry

F

1

Generation: RrYy

Selfing of F

1

Genotype: RrYy X RrYy

Gametes: RY, Ry, rY and ry X RY, Ry, rY and ry

F

2

Generation:

RRYY RRYy RrYY RrYy

RRYy RRyy RrYy Rryy

RrYY RrYy rrYY rrYy

RrYy Rryy rrYy rryy

Thus, it is clear that RrYy occurs 4 times in F

2

generation.

Answer 2

ᴛʜᴇʀᴇ ᴀʀᴇ ғᴏᴜʀ ᴘᴏssɪʙʟᴇ ᴄᴏᴍʙɪɴᴀᴛɪᴏɴs ᴏғ ɢᴀᴍᴇᴛᴇs ғᴏʀ ᴛʜᴇ ᴀᴀʙʙ ᴘᴀʀᴇɴᴛ. ʜᴀʟғ ᴏғ ᴛʜᴇ ɢᴀᴍᴇᴛᴇs ɢᴇᴛ ᴀ ᴅᴏᴍɪɴᴀɴᴛ ᴀ ᴀɴᴅ ᴀ ᴅᴏᴍɪɴᴀɴᴛ ʙ ᴀʟʟᴇʟᴇ; ᴛʜᴇ ᴏᴛʜᴇʀ ʜᴀʟғ ᴏғ ᴛʜᴇ ɢᴀᴍᴇᴛᴇs ɢᴇᴛ ᴀ ʀᴇᴄᴇssɪᴠᴇ ᴀ ᴀɴᴅ ᴀ ʀᴇᴄᴇssɪᴠᴇ ʙ ᴀʟʟᴇʟᴇ. ʙᴏᴛʜ ᴘᴀʀᴇɴᴛs ᴘʀᴏᴅᴜᴄᴇ % ᴇᴀᴄʜ ᴏғ ᴀʙ, ᴀʙ, ᴀʙ, ᴀɴᴅ ᴀʙ.....